late to the party, but you can't bond plastic. it's simply common sense, so you might want to do a 2 hour video on what common sense is :-D (bad danish joke)
"You can't apply bonding to protect from faulty installation elsewhere." I wholeheartedly disagree. Workmanship is always a variable when making standards, and overlapping protections save us every day.
@@lhffan But, you asked what we would do. We know that there are idiots who do unsafe work. We also know that we are all human and minds do wander. On the other hand, if the fault was in the consumer unit, bonding it could make things much worse.
It’s either earthing or bonding, they’re two separate functions. The sink isn’t an exposed conductive part, therefore not required to be earthed. The sink “could” be an extraneous conductive part, if so, it would therefore require protective bonding. If not, no protective bonding. There’s a test one can do to prove if something is or isn’t considered extraneous.
I had a thing about 15 years ago . Plastic incoming main . All the pipe work in the flat was plastic. Customer had a electric shower and complained he got a nasty shock . Shower was about 8 foot away from the incoming plastic main. Couldn’t find anything wrong on testing. It was also a intermittent thing..After a lot of head scratching it was Infact a fault on an adjacent flats water heater .The element was faulty, so was the voltage operated trip. The fault was Infact traveling through the water in the plastic pipe into my customers flat and earthing through him when he was stood in the bath using the shower.. most tradesmen round here still use copper but if it’s plastic I get them to put a small copper section in so I can earth this so this sort of thing never happens again . This was a potentially dangerous situation that no one seems to consider
I live in Germany. We have TNC-S and a plastic water pipe. The pipes in the house are made of copper and are bonded to the foundation earth. The house is almost 50 years old. As far as I know, the heating engineer has requested that the earthing is available, so the earthing is not at the inlet of the pipe but on the heating system. But that doesn't matter with copper tubes.
To the “I’d bond it anyway” brigade the video clearly shows that when it’s not extraneous it’s no different to any other metalwork in the property. If you “bond it anyway” you’re going to introduce a fault current that wouldn’t otherwise exist. We’re all about keeping fault currents away from people yet bonding an irrelevant piece of metal is increasing the chances of someone coming into contact with live metalwork. Or am I missing something?
Exactly 💯 buddy. Its potentially putting someone at risk of electric shock in the event of the pipework becoming live because there would not be a return path.
@@squakkers probably hard to prove its not once the plumbing is fully assembled mate. Have to trust the original designer... But given some of the comments on here that's probably easier said than done.
@@squakkers it's a dark area that one. Tbh I would consult niceic (since I'm paying for 2nd opinions) and get advice if I couldn't clarify. The internal pipework throughout the building can in itself be unpredictable. Ie bathroom fitters rock in and cut into the copper slapping in plastic pipe potentially breaking continuity. Put on the spot.......I would agree C2 if certain and fi.......if uncertain. Don't you just love earthing arrangements 🤦♂️
The plastic pipe obviously doesn't make a direct connection to earth, but what about any metal pipe fittings further down the road? At mains voltage water can act as a conductor (or we wouldn't worry about IP rating for things exposed to damp environments) so while the path to earth via the pipe itself doesn't connect to earth directly under the house, surely there's a path to earth via the water in the pipe itself? I accept that the potential is probably a lot lower than the actual copper earth that comes into the building though, so likely wont be a problem, but I would still expect that there is the possibility of an issue there.
@@simongreenidge6454 Where I do think there could be a concern is when the insulating section is very short. If there are meters of insulating pipe then the current is going to be reduced to non-hazardous levels, but if there are only a few centimeters of insulating pipe between sections of conductive pipe that could be a different matter.
@@petermichaelgreen Yes, an interesting situation. This video also makes me wonder whether, in a house with a plastic incoming water supply pipe; does any of the network of copper water pipe within the house be (supplementally) bonded e.g. the bathroom?
There's one more issue: The whole house is at "real earth" potential unless it's built on plastic foundations. Usually that doesn't matter, plaster, bricks and carpet aren't good conductors and the area we touch them is quite small. But now you have copper pipe through your whole house that is buried in brickwork. It makes contact over a quite large surface, plenty of parallel paths---and Ohm's law on parallel connections starts to raise its head. I'd recommend to measure the resistance between "real ground" and any touchable metallic object to decide if it should be bonded.
Yeah and if you do bond onto plastic water pipe (but a piece is in copper) what about the millions of gallons of water in the pipe, no one mentions this.... What do you think
@@tomcapon4447 But Tom... I got 15mm copper pipe then going to plastic.... But its full of water... Millions apon millions of gallons of water... So it won't travel through that?
On a brand new install i would accept the non-bonding of plastic incoming water pipes ( what about plastic gas pipes then ? ) Existing installs can and do bring the risks of cables being found under floors etc resting on metal heating pipes etc ( but they could now be all plastic !) The discussion on protecting metal sinks on older BS7671 regs brought similar conflicting views didnt it ? Personally, I'd still bond and do continuity tests to verify integrity.
"We can't bond just to cover poor installation" This is a correct statement... However. I was receiving shocks and tingles from my New washing machine and kitchen sink, turns out Mice had chewed through the Flex feeding the washer. This left the live conductor touching the water feed pipe and therefore livened-up the whole unbonded house water installation. Makes you think ?
There is a difference between grounding and bonding. The washing machine should have a proper ground wire that is wired to house grounded system. The flex cover should be bonded too.
Joe you cannot state that if the service pipework is plastic then it does not require main equipotential bonding. It is possible that elsewhere within the property that the installation copper pipework enters the true earth and comes back up again, and therefore can be deemed extraneous. A simple test to prove is what I do,....continuity test between the MET and the pipework. If the reading is
Regulation 411.3.1.2 states it. If the metal pipe enters the ground as you've described then it's a different situation and may well need a bond, if it changes to plastic where it enters and exits the ground it won't. I know what you're saying though Andrew and there'll be much more information on this subject on the way. 😊
Interesting video, but I suspect the more complex answer is "it depends". You're only considering the water supply as it enters the building. What if some of the copper is in contact with the earth elsewhere, e.g. a kitchen island? If you can guarantee that it's not, that there is probably more danger of metallic parts becoming live under fault conditions if they were bonded. However, it's also very likely that a boiler (for example) will have all the metallic pipework bonded, so the point is probably moot anyway. If in doubt measure it, and make a decision based on that.
This literally came up on r/electricians this week. Pipes not bonded at entry, shorted to hot through a stray wire, and now all the fixtures in the house have live voltage on them relative to anything plugged into an electrical outlet.
would the dpm in the floor act as an insulator to avoid contact with earth, plus you would use plastic pipes to an island to avoid the corrosion of copper , simple answer cross bond gas water and heating pipes
actually, the issue with metal piping in the ground is just the opposite. the earth is NOT a low impedance path to ground, and the bonding network is. so by bonding metal service piping, you are bringing that piping to the same potential as your ground reference. it's not such a big deal with household voltages, but you can get a palpable voltage gradient if distribution voltage starts leaking to ground. in the US, the relevant clause in the code is to the effect of, metal piping must be bonded if there is a possibility of it becoming energized. the usual interpretation of that is that a metal fitting under a sink is not likely to be energized unless it is connected to an appliance - and the appliance will be bonded, so there you have it.
I knew it!!! I thought it did not make sense when my electrician said my incoming water mains must be bonded even though it comes through MDPE pipe. Glad this video sorts it out!
In one job the guy came to change the gas meter, saying where is the earth cable to the water stop cock. We told him it is not needed as it was plastic. He left not doing the job. As he was leaving we called him an incompetent lazy ****. We kicked up about it and in also stated it was not needed quoting the reg. And not to send back this incompetent idiot. They apologised sending a different guy.
It’s recommended to still bond if the rest of the installation is all metalwork. What he said in the video about cables being spaced away from pipes is just wishful thinking. Look under your floor boards, cables wrapped around pipes is basically guaranteed, check your boiler, immersion heater, appliance cables behind sinks etc. You’d be deluded if you think everything’s a1 just because you can’t see it.
@@Chris-gt3rs With RCDs and RCBOs the need to bond a pipe not connected to earth disappears. No need. As was stated you do not design a system expecting it to be a cowboy job.
Since the city water is conductive enough to prevent static charge from building up with a non-conductive pipe it's not necessary, but if the pipe were transferring a non-conductive fluid such as oil or gas, absolutely ground both ends of it as the friction between the non-conductive pipe and the flowing non-conductive fluid builds up a static charge.
@@davidhilton7780 yes absolutely, but any conductivity in the fluid will drain the charge away, but of course with enough friction and not enough conductivity you can get a charge building faster than it dissipates.
@@TurboBaldur so wouldn't bonding both ends of a non-conducting line to conductive ends safely dissipate the static in the line and reduce the risks...
Once the metal pipework enters a class 1 appliance, like a water heater or central heating boiler, it will likely get bonded anyway via the chassis being earthed.
@@Orgakoyd by human error or accident , in europe can happen especially with boilers or washing machine . sometimes you can get electrcuted just on the wet floor
There is the electrostatic potential, and the flow of water can still give a little charge. I have seen dust cling to plastic water pipes in use, although current is minimal the field is quite large.
Most of what I was going to say has been covered below, especially Tom Capons post, but all you need to do is ask a simple question. Will bonding it make the installation less safe? obviously not, Will bonding make the installation more safe in the event of a fault? Yes it will, so you put it back. you do not know that plastic pipe has not been installed elswhere in the building that has isolated this part of the conductive pipework from other bonding at boilers, immersion heaters etc. Regs are there to provide safety( or used to be!), It is the engineers job to ensure safety, not the regs, and anything done to enhance safety is good. Mere compliance is not good enough, just an A*se covering excercise. The attitude that," the regs say I dont have to do it so I won't" is what kills people. I was trained on IEE 14th metric 1970 and have CGND Electrical Engineering. I am afraid I have little faith in the IET as the regs are difficult to understand, contradictory, and open to interpretation, which the IEE regs were not. We were trained on every regulation till we had been through the entire book TWICE, and then examined. You were allowed one retake if you failed, and then you were out of the college, and out of the industry, today, everyone passes
Totally agree about the regs. Continual incremental changes to generate more revenue for themselves and their manufacturer sponsors. The whole book needs a complete revision with thorough proof reading to eliminate the confusing terminology (who thought up the distinctions between extraneous/exposed/equipotential ! ) and numerous ambiguous contradictions. And why the need to change section numbers at all - as if there were not enough subsection levels?
I am not an electrician, but part of my job in an electronics based industry included reviewing technical specifications of the same order of complexity and detail as bs7671, though not usually so long. At best the section as a whole is made AMBIGUOUS by the second line you highlighted. At worst, it lures you into taking the second highlighted part to trump the first. My department would have asked for it to be rewritten to remove the ambiguity, if it was a specification of ours! Electricians take it to mean no need to bond if the water incomer is plastic, but I read it as meaning this: "If you have metal water main coming from the ground but a plastic stopcock or the like interrupts the conductive path, there is no need ALSO to bond the metal part rising from the ground, on the supply side of the break. Only bond the metalwork on the consumers side of the insulating break" The purpose is equipotential bonding. It says so in the heading. If you don't bond the water pipes, etc, you do not HAVE equipotential bonding. My interpretation - that you don't ALSO bond the little bit coming from the ground resolves the apparent conflict. BUT IT NEEDS A REWRITE! In almost every case this piece of pipe at "true ground" will not be more than a few inches long. The context is important, too. It is about EQUIPOTENTIAL bonding. A fridge next to a radiator will be connected to the CPC. It is logical that the radiator too is at the same potential, possibly even if a PEN fault has developed. That is what I take "equipotential" to mean. If you do not bond the pipes then the scenario you kind of dismissed might arise, that a fault - or dodgy workmanship - might cause a potential difference between metal cases of class 1 electrical equipment and nearby radiators, gas pipes, structural steel etc.
Like someone else has said I wondered about the water conducting. I am not an electrician, but have this question which many DIYers must have come across. Metal pipe into the house and to the sink with bonding at the taps. Kitchen redone with all plastic plumbing from the point the water comes into the kitchen. Stainless steel sink fitted with metal taps, but plastic tails and plastic as far as the kitchen door. I assumed that because the sink is insulated now there was no point in any sort of bonding. In fact even when there was bonding I was never sure of the logic on a metal sink. I sort of thought I understood on a plastic or pot one that connecting the hot pipe to the cold gave a route back to earth so that seemed sensible.
We do the main bonding usually in the hot press in Ireland, under the sink would be supplementary bonding to the sink, but in the new regs due to lack of bonding points, ie no flange on sinks plastic pipes and flexible braided pipes. if we prove there's no earth path we don't have to bond, ie via insulation test .
I've always been puzzled about bonding, the reason being, every piece of metal pipework is connected to a CPC, maybe not, but I can't think of the scenario when that's not the case. If you have a gas supply and boiler, the CPC for the boiler connects any metal pipework to earth as would any water heater. A gas boiler connects the CPC to both the water and gas, though I do seem to remember that some boiler manufactures don't do this, I'm not certain of that. When the water companies changed the network to plastic a lot of older properties lost their earthing system all together, as it used to be common practice to use the water pipe as very reliable earth. There are thousands of properties, especially older ones that no longer have a proper earthing system. Why aren't there dead people everywhere due to this issue?? Totally agree that there's no point bonding metallic pipework if the incoming pipes are plastic. Great video and thank you.
@@efixx Thank you for replying, when you say most CPC's will need a bigger cable it would depend how the earth fault was initiated. The adiabatic equation proves that most CPC's can withstand a far higher fault current than the protective device will let through. Food for thought.
The need for good grounding is to trip the breaker at a fault. The safety of the house comes from having one single potential on all toucheble surfaces. If all metal pipes, electrical enclosures and house frames are bonded you will not get electicuted even at a fault. No need for good earthing 😀.
@@J0nny61 we are not concerned with an internal earth fault when we talk about main bonding. We are concerned about bringing all extraneous metalwork to the same potential as the installation earth. The bonding conductor will be sized to cater for diverted neutral currents
It's correct name is equipotential bonding. Why? Because all points are at the same potential. Let's not get confused between earthing which CPC's are for, and bonding. They fulfil two different requirements.
My boilers gas pipe will bond the water pipes but this may give a potential difference as it's not as direct as bonding the water pipes directly. This applies to indirect earth connections via an immersion heater, the motorised valves, a waste disposal etc etc. The pipes to radiators or an outside tap may also be contacting the ground at various points so I think pipes should be bonded regardless to assure continuity of earth protection, seems daft not to.
The gas pipe might be bonded but why does putting supplementary bonding on water at point of entry help? If you need supplementary bonding - which given exemption for RCD protected circuits you can't imagine how you ever would in a modern domestic installation - then you'd install the supplementary bonding in the bathroom not at the stopcock.
Agree with this video but for some reason I still would prefer to bond it. Plus, isn't water conductive and technically there is a solid H2O conductor running inside the pipe which at some point will be in contact to earth via a pumping station, long shit yes but I don't entirely agree that your copper pipe is entirely insulated because you have plastic pipe. Who knows what's underground a few hundred yards away. I'm not knocking your video, you are correct, just old habits are hard to remove from the older generation. 👍👍👍👍👍
@@sm1thers no. Just measure the resistance of the part for goodness sake. If it's greater than 23kiloohms it's not extraneous. Possibly lower depending on circumstance.... No complex maths... Just knowing how to do your job.
I would bond internal metallic pipes because of the risk of they being in contact to the line conductors at some point. That should not happen in a well done electrical installation, but accidents happen and there are bad electricians who will leave wires exposed near metallic pipes.
This is to assume that the only connection point between the ground and the water pipe is the incoming pipe. An underground feed in conductive piping to a garden tap or outbuilding would do the same thing. There may be other possibilities too, whereby the property's internal conductive pipework has a connection to the ground. It may be rare, but it surprises me that it is not mentioned in the regs as a possibility. Of course, the most likely way that the copper piping would have a connection to the ground would be via a gas boiler if the incoming gas supply is via conductive pipe, but then the bonding on that ought to deal with the situation.
In the US it does require bonding. The water in the pipe is not pure, therefore it is conductive. It goes through a metal pipe in the earth somewhere. That is why we ensure all metal pipes are bonded on the US. If metal water pipes are separated by plastic pipe we have to bond both sections. Note to those who would argue with me about the water not being pure: When I say it is not pure I am not talking about how safe it is to drink. Safe to drink is a different metric as compared to purity. Tap water contains minerals. It is not pure H2O until it is distilled. All drinking water and residential tap water has minerals in it.
My thought is the pipe should be bonded as soon as it turns to metal inside the house; Reasons 1-Do you know the whole supply pipe is plastic? 2-i have seen supply pipes where the last foot has been converted to plastic but the rest underground is metal. I know tap water has a quite a high resistance per metre inside plastic but it would still provide a conductive path. 3-What if something is changed in the future and ended up grounding your copper pipes. Better to locate the cable & clamp than do it at a later date.
Yeah. If you earth something that doesn't need to be earthed, ( as you said bedframe), then that creates a dangerous situation, because now if you touch something live, and that earthed object, the current will shoot through you.
@@davepusey RCD will reduce the level of electrical shock that you may get. But you'll still get a belt but for a shortish period of time. RCDs used for protection on sockets are rated at 30mA. Studies have shown that 'usually' the heart needs over 40mA for 200mSec to go into fibrulation so it is calculated that 30mA will give a reasonable level of protection. They are not a catch all 100% safety blanket. they are an electro-mechanical device and (as such) can go wrong - that's why they need to be tested every 3 months. If anyone disagrees, how about standing on a wet floor, and put your tongue on a live cable.
if you are reading from an old code book it may be required in the updated book. if you are reading from a new book then it may have been required and discontinued. the only reasons i can think of why to bond plastic pipes os. 1. a financial kickback the more stuff you have to install the more the industry makes money so maybe grounding wire and clamps cost money and it was done for money. 2. static charge certain contents may cause static build up so it was done to bleed off static. 3. ground loops if there is a section of plastic between 2 metal pipes it is to keep all the metal sections at the same level. 4. plumber was out of pipe clamps so he used an electrical clamp but if that is the case there should be no reason to connect a grounding wire. unless the code book sais that any electrical clamp in the system has to be grounded.
JOe's analysis of the potential between the neutral at the entrance and the grounding conductor at the transformer is a bit hyperbolic. In the US NEC, there shall be a local grounding conductor in contact with the earth and connected to the ground potential terminal in the breaker box (that is the Green conductor). Bonding to the incoming water supply pipe is one method of creating a grounding connection. Other methods are to connect the earthing conductor to a grounding rod of at least 8 feet (3 meters) driven into the ground, or the attach the conductor to the metal reinforcing rods in the concrete of the foundation. (Ref. NEC-1999 article 250-C). Any non-conductive pipe shall be bridged across from the grounding electrode to the metallic interior pipes, and the exterior grounding water pipe shall be in direct contact with the earth for 3.05 meters. There is another regulation in the IRC abound the distance from the entrance of the metallic pipe to the electrical earthing conductor.
I heard about an EICR recently that had missing earth bonding labelled as a C1. Tennants had to be relocated as the rental agency freaked out. Shocking!
Interesting, I have a blue feed pipe and have earthed internal pipping but was told to also earth stake the internal side of the stopcock with 16mm. This video got me thinking, I had wanted to run a soft copper insulated radiator supply a short distance to the garage in the ground, & the boiler is external oil but the oil supply pipe does already run in the ground !!! This is going to be sleeved in the future but never the less getting wet. & what about old house pipes that in concrete floors. The supply in is overhead line & earth with a main RCD.
In The Netherlands every home has there own earth-rod connection to the earth. The water inside the pipe may be conductive as well. Therefore inside a bathroom a metal schowerdrain, a metal radiator, warter-taps etc etc are bonded to an earth-wire as well. In older houses with wooden floors, where there is a steel floor-support (in concrete on top of the wooden floor), the steel is earth-wired as well. Is that different form the UK?
Yes, most connections in the uk, except for a few rural properties have either a separate earth connection from the local distribution, or an earth connection which is tapped off the neutral as it enters the property (and the neutral is regularly earthed along its path from the transformer to the property). Bonding varies depending on the age of the property and what wiring regs were being worked to. Building metalwork is also bonded, but steelwork is not very common in uk homes (it’s only usually in one off type builds or commercial buildings). It’s amazing to see how differently different countries approach the same problems.
My house has plastic pipes coming in, but I don't know that there aren't any parts of the internal metalwork touching anything conductive that's in the ground... In fact I'm pretty sure that the metal pipe to the oil tank will be connected through the combi-boiler. This old install is bonded and I'm keen to keep it that way
Agreed, no need to bond, no point at all. I have a new build, plastic pipe and bonded anyway, I thought builders were all about saving any money they could?!?
Quite often I come across Radio Hams on a TNCS system, but with their own "RF" eath that can be anything from and aditional earth rod of some description driven into the ground to a whole scrap car buried in the garden. Some are insistant that the RF and Mains earths have to be isolated from each other, some ask why a multimeter shows a voltage difference between them, and some will actualy allow a bonding connection between them. I always suggest that the RF earth can be improved by linking them and quote ohms law :)
Hi Steve, I qualified as a radio Ham a long time ago. Separate “Earths” for power supply (mains) and Radio Frequency (RF) The mains Earth (CPC) is for protection from electric shock and for removal of power under fault conditions. This Earth can cause noise to be introduced into circuits from switch mode power supplies and power line adapters etc., RF Earth is to provide a low noise reference to incoming signals to the receiver and to provide a separate Earth for the transmitter aerial which is outputting considerable radio frequency currents. The RF Earth, very often, is part of the aerial system. There would be problems if this high power RF current was connected into the house wiring via the Earth (CPC). Ham radio equipment has a special “Earth” terminal for RF. Ham radio equipment manufacturers advise not connecting to the mains Earth (CPC). I do not transmit but just listen and all of my receiving equipment has this advice.
@@dougmorris2134 The definition of an extraneous-conductive-part as defined within BS 7671:2018 is as follows: “A conductive part liable to introduce a potential, generally Earth potential, and not forming part of the electrical installation.” ... Not forming part of the electrical installation. Your RF earth requires bonding :(
bonding is there for failure a broken element in your boiler can create the whole thing to come live .. if lightning hits pipework in your loft it needs to go to ground... a modern house were all the pipeworks made out of plastic I will agree.. what your showing needs bonding
Hi Joe, I would still bond! The reason being that as water isteslf conducts electricity it becomes a return path and thefore a potential difference to the installations 'earth' value as regards an equipotential difference! Regards David
The plastic water pipe is only isolated when it is dry, otherwise it is connected to ground through the water within it so any metal pipe connected to this plastic water supply pipe is grounded through the water itself to nearest conductive pipework in the ground. A ground can also be formed through a water leak. If there was a fault applying a voltage to metal pipework connected to a plastic water main there may appear to be no problem until one day there is a leak and the pipework is now effectively grounded creating a return path. This leads to a situation where it could be rather difficult to determine why breakers suddenly start tripping for seemingly no reason (possibly intermittently), people suddenly getting electric shocks in the bath or shower with seemingly no apparent fault and other anomalies. Whereas if the metal pipework was grounded the fault would be apparent straight away and not seem to disappear and then return as well as there being a ground connection that could me tested for current flow which would drastically increase the possibility of diagnosis in a timely manner and genuinely protect peoples lives.
Commenting from the other side of the pond, there are benefits to bonding sink piping and fixtures to earth. Customer safety. Bathrooms/washrooms have a GFCI receptacle for personal safety if a hair dryer or electric appliance fall into a sink full of water. If the metal faucet fixtures are not bonded, (PVC DWV pipe and/or pex/CPVC supply lines) the electrified water has no discharge path except thru the person to the floor. If the faucet, sink and flex piping is bonded to earth, the GFCI will sense the fault and trip. Without the fault, the gfci will happily keep the appliance electrified and running since the electricity is flowing into and out of the device as planned-no fault, but a deadly condition still exists if a customer reaches into the sink to pull out the device. There are videos where electricians have turned on hair dryers, dropped them into a sink filled with water and the appliance happily keeps running since no fault current is detected by either the socket's GFCI nor the device's GFCI plug. I'm not familiar with UK RCDs to know if they will detect this condition and protect occupants in the same way.
This analysis is wrong. Consider the scenario where there is no bonding and a GFCI is present. If the customer reaches into the sink and there is a dangerously high potential present, the customers body acts as a resistance to earth and current starts to flow through them. The live and neutral currents are no longer the same and the GFCI trips, cutting the power off and preventing electrocution. Dropping a hair dryer in to the water in the sink with the hairdryer switched on doesn't result in the GFCI tripping because the live and neutral currents are the same, there is no path to earth. The porcelain of the sink is an insulator . As soon you put your hand into that water, there is a path to earth through your body, there is potential across your body, and that potential difference starts to cause a current to flow through it, which now means the live and neutral currents are no longer the same, and hence the GFCI trips. So yes, placing a hair dryer into water creates a dangerous situation, but the GFCI will prevent the person being electrocuted. Earth bonding the metal water outlet pipe and the metal plug hole (if it is made of metal) does help, as it should (not guaranteed) cause the circuit breaker in the consumer unit/distribution board to trip. But the safest way to prevent electrocution is through the use of the GFCI. If the outlet pipe is plastic then bonding it is pointless as it is not conductive (except at very high voltages!)
What if there is a bond wire to the cold water pipe inside the apartment. At some point, the plumber replaced the feeder pipe with PEX. Is there an easy way to check whether that was the main earth ground of the apartment, and would it need to be rebonded or to add earthing rods?
Good video, ta. I'd bond it, I've just been in a house where the owner drilled a cable (but didn't realise it at the time) when fitting his metal curtain tie backs. The tie back was lightly touching a painted central heating pipe, which was sitting at about 190v to earth. The reason I was called was that he was getting shocks in the shower. Neither the mcb or rcd was tripping ( no idea why, the rcd tested ok). If it had been properly bonded, it would have tripped. It had been like this for about 2 months!
Good day this is Mike from Amsterdam Holland we got the same problem here but the regulations are you have to bond your tube because when it conduisait it will still conduct the bonding
Even tho the water pipe entry is plastic, the copper pipes in the house come into contact with all sorts and if you measure a resistance to earth, then it may need bonding.
Here in Germany it's different. The incoming gas pipe is usually plastic, after the meter usually metal. You'll have to bond that metal part. Copper piping for the radiators -> bond. Shield of incoming antenna cable (cable TV or satellite) -> bond. If the incoming gas pipe is metal and has one of these short plastic pipes in between as an electric isolator you are only permitted to bond the pipe after that isolator. If you want to bond the part before the plastic isolator you'll have to implement SPD into the bonding wire. Until 2003 we even bonded metal bath tubs and shower trays because they were considered as being extraneous conductive parts. And they still have the terminal for a bonding wire today, for in case you install it in old installation. Because there you'll have to bond it again with at least 6mm² copper wire.
@@สมบัติสตีเวนสัน-น6ษ Maybe, but cast iron drain pipes were state of the art during the 1950s. Later in newer constuctions replaced by non-conductive glazed ceramic pipes, and then again by plastic pipes. Inside of the building polypropylene and outside PVC-U (unplasticized PVC). The PP can handle higher temperatures better than the PVC and is also more resistant against corrosive chemicals like detergents from dishwashers and washing machines. But the PP can't handle to be buried directly into the ground, you either use the PVC or embed them into concrete t reduce the pressure caused by the soil it's embedded into. For easier determination the PP pipes are grey and the PVC ones are orange or brown.
I've seen a voltage difference between cold and hot pipes within a house form when the hot water pipe heats up as a tap opens. I'm just wondering if in future a reg will come out with a bonding portion of pipe to bring the water to a zero potential.
3:12 "And because fault current is usually quite high, the voltage pushing it along can get quite high too". Apologies if I've interpreted this incorrectly, but the fault current will only be high if the voltage, or the potential, is high. The resistance between the fault and the ground source will dictate the voltage and thus the current. My understanding of equipotential bonding was also to do with the potential influence of other phases within the area. eg, the neighbours house could be on L2 whereas my house is on L3. A fault on their shower could introduce a potential between close pipework and a grounded receptacle in my house. In other words, it ensures that all potential fault currents across the area have a common (neutral) path to the center point of the transformer.
Almost right on the first point (unless you want to get into quantum mechanical explanations of electromagnetism). It takes a voltage to drive a current. BUT don't forget there is a current in the supply side too, so that drops a voltage; the voltage at the fault point is based on the ratio of the resistances on both paths to the transformer. Assuming (!) they are the same, the voltage would be about half the expected supply voltage. Slightly less resistance in the return path, and the voltage will be slightly lower than half.
Depends on what sort of floor the house has, if it's soil under boards like in an old terrace, there's a chance of pipes resting on the soil even if the income is pvc. Then there's a chance of the floor being unfilled and concerted to stop pooling surface water on the surface.
My plumber fitted a new stop tap, he used a plastic push fit connector onto the main water feed in then copper pipe then stop tap as it was live when he changed it. He left the bonding wire disconnected. Now because I have a plastic connector between the main feed and the house pipe work does it still need bonding as the old wire doesn’t reach to what’s left of the inlet feed pipe
I think a return to the physics lab might be in order. Some interesting experiments in contact with water from metal and then water in MDPE which may or maynot be a presurised pipe or empty from water completely! Earthing, bonding and a mix and match of both people like to use is not the answer to all situations. Let's go back to oil lamps and candles and avoid the electric shock but careful not to burn your house down :)
From another country so please excuse my ignorance, but given the water is conductive enough to cause electrocution and is likely contacting the literal earth just outside the property at the next metal fitting and thus has potential, why would you not bond it anyway to ensure no potential shocks? In my country our version of TN-C-S also adds an earthing steak at the property to help prevent this situation. If you have disconnected all your bonds from the incoming water supply you can test this by checking the voltage potential from both your taps and electrical Earth. I'm also surprised you don't have an earth steak, what would happen if you touched a metal exterior wall mounted light and the literal earth in the rain?
I would leave a earth bond floating around the incoming water on a new rewire just incase there is some major change to the water supply...unlikely but the hassle of not having it around is more... But not connect... and just leave in board but mark it not connected... Depends lots of variables..
I'd bond it anyway because you have no way of knowing if the homeowner has installed a metal pipe elsewhere that exits the building, to an outhouse etc. If there was no plastic between that and the incoming metal stopcock then the pipework would then all be at earth potential. You could argue that that shouldn't happen but it's unlikely that a home diyer or plumber would consider that and possibly neither should they have to - it's the electrician's job to ascertain that and plan ahead for it. You mentioned a possibly scenario for not including bonding because it shouldn't be relied upon to prevent danger where other regs have been violated but then surely that is the same for a metal pipe coming in. The earth bonding is there to provide a path back to the panel in the case of a fault which could occur even with a plastic pipe entering, such as driving a nail through a pipe and cable at the same time... I'd say the difference would be that the bed can be moved but the pipework cannot be so should be bonded. You could argue though that the bonding could occur at the most convenient location and not necessarily within the regs distance of entry to the building...
When the main water pipe is metal and the internal pipes are plastic, which is quite common, the few inches of metal pipe into the house needs bonding.
Totally agree, bonding is not needed. Water in the pipe really is a poor conductor - not enough ions in it, so quite high resistance path - higher than the alternative (wiring), or if it were in a metal pipe (copper, iron etc). One minor comment, the two earth points will not always be at the same potential ("0v"); I don't recommend measuring unless in a very controlled environment, but if you disconnect ALL the bonding and measure during a thunderstorm, you'll see the effect...and depending on local conditions, the resistance can be low enough for a respectable current (or can be just potential).
Definitely earth it. I have just discovered my stopcock was live due to fault on Powergrid cable making my earth rod live. Powergrid told me the water pipe should be earthed but the supply pipe installer failed to tell me.
So if your earth rod is live and you also earth the water is that not live too? If it’s plastic then it can’t become live, the only way it can become live is if you then earth the copper pipe.
@@DTech101The water was live, cooper pipework, taps, bath, all metal surfaces including radiators. They tell me it's now repaired as they've replaced the 90 year old box on the utility pole and part of the cable but I'm terrified!!
@@DTech101 Yes there was nothing wrong with my side it was their equipment energizing the lead on my supply cable, but they've confused me by saying my water pipe should be earthed also. I've since been told that wouldn't have made any difference as the earth rod was energized.
My home in the US has plastic PEX piping and it is not bonded to the electrical service ground. Code does not require it. However, water is a conductor and water flows from buried metal pipe in the street and comes in contact with metal valves and fixtures in the home. Could a voltage potential be applied somewhere in the system, perhaps a faulty electric water heater element? Perhaps bonding at a location near the entrance via a stainless steel or brass pipe fitting might be a good idea?
@@stuartcraigon2003 your combi boiler is earthed through the spur , so you have continuity through the combi boiler to the internal copper water pipe , so your potential on the copper water pipe has a potential of 0V, even if incoming water is plastic.
Unless the incoming water supply is demineralised water then it will be conductive (If there were any more minerals in our hard water local supply, it would be supplied in sacks). Regardless of the entry to the house, some of the downstream supply pipework may be metal anyway so there is possibly still a risk. Has there been any investigation as to this being credible? Edit:- I have read some more of the earlier comments regarding water being conductive and I would add this observation based on my experiences in power stations- Demineralised water is non conductive, in fact it is used to cool HV stator windings in large alternators. Insulating pipework lies between the windings and the pumps. However, town water supply is conductive otherwise the electrode boiler (that was used for emergency use in part of the plant) would not work, as it depended on high currents passing through the water within. My personal choice would be to bond anyway, as the IET rules on earthing seem to change rather often.
The main water supply have probably something, somewhere, metallic (an older pipe, a shutoff valve, etc) touching the water inside the pipe, and the earth outside the pipe. So the water is touching the earth via this part. Then if you have something metallic in your installation inside the house, touching the water, a faucet, a valve, a pipe, then this metallic part is touching the earth too, via the water that is touching the metallic part outside, that is touching the earth... 🤷🏻
How about this scenario, “a non extraneous” water pipe with an insulating section at its point of entry doesn’t require a main equipotential bond. So what about when this turns internally into a copper water pipe installation, then this copper pipe is installed into a metallic boiler manifold. Then this manifold connects to the extraneous gas pipe work (with a metallic section at its point of entry) surely now this “common” copper pipe work is now deemed to be extraneous???? And how the hell do you successfully perform a 22K test on “commoned up” gas and water copper pipe work installation? 🤷♂️
@@markpotter8280 yes I agree but the extraneous gas pipe work is making the non extraneous water, an extraneous conductive part, and there’s no way of separating the two.
Go to 1:08; it says "Metallic pipes entering the building having an insulating section at their point of entry need not be connected to the PEB." - ie; you do not have to bond to the utility company's incoming metal pipe, should it exist. The clue is in the words: "Metallic pipes entering the building". You have a plastic pipe entering the building. Section (i) 5 lines above it says: "Water installation pipes". That includes all metalwork connected to the water pipes on your side of the plastic building-entry pipe. Here is a sample reason for earthing all metallic parts: If you have a fault in your immersion heater/water heater/pump etc, it will render the entire house heating-system live, radiators and all if it is not bonded. Read the rules, they are there for your protection!
The same reg states that the metal water pipes will need bonding if they are extraneous conductive parts. If they're not introducing 0v potential they're not extraneous and won't need bonding. It's not being a water pipe that makes it need bonding it's being an extraneous conductive part.
A PEN fault will promote an alternative return path for neutral current through any extraneous earth connection ie metal water or gas pipes, either from the property affected or as a bypass through a property from an adjacent property on the same supply. Plastic service pipes do at least prevent a dangerous rise in main earth current due to PEN faults. They are more common than you think - check out Team Electrical podcasts 1 and 2 on Diverted Neutral Current. We are not taught to think critically so we expect the DNO head to be whatever it appears to be. Today most service heads are TNC-S and not TNS because somewhere outside the property a repair to the old PILC cable will have made the supply TNC-S. The only exception might be in a rural area where supplies are mostly fed overhead.
I would bond metal pipework, There are that many metal central heating pipes and cold and hot water pipes in contact with the ground that there may be a chance that your plumbing would be in contact with the general mass of earth.
Very well put. I'm of the same mind it makes sense not to connect it but having it connected doesn't seem like it would be that much harm and would be extra insurance in-case of an unintended fault. I'm not thinking poor workmanship that should be the above all standard is that accounts for so many things. I'm thinking water heaters and boilers which are already grounded anyway having a fault or other water loving electric appliances. And well water is non-conductive in a pure state most water has some minerals in it so it wouldn't be truly nonconductive. So does this mean if I have plastic piping going to my tub I can make toast in the bath? Well apart from the GFCI/RCD.
My house has bonding in the bathroom, kitchen and down stairs loo. But the pipe bringing in the mains eater to the d s loo is plastic. All water supply pipes in the house are copper except the ufh on the ground floor. So if all copper pipes have bonding but I do not believe is bonded back to ground? So what is the point, think the house was built in the 70"s Should I bond the nearest pipe to the supply metal protective shield, which is under the stairs and the ufh manifold 22mm copper pipes are there to approx 1 meter away. Thanks for the thoughts on earth bonding and video.
In the USA is impossible to bond or ground anything that does not conduct electricity like plastic pipe. If you have plastic pipe feeding water to a metal kitchen sink that has plastic drain you should bond sink.
So out of interest on the EIC do you put N/A in the tick box then? Would this be sufficient or would you need to prove bonding is not necessary by providing a measured resistance value to prove it isn’t required ?
I think you're playing devils advocate here Joe!! In the video, you've completely ignored the issue of metalwork within an installation picking up an earth potential along its route by virtue of being buried in the ground, for some reason, despite it having a plastic supply - see, for example, sections 4.3 and 4.5 of the OSG.
Not intentionally John, this is the first video of many on this subject and you're quite right about pipes entering the ground elsewhere, however that would be a different situation to the one considered in this video. We'll get to other scenarios down the line. 👍
In the sketch he says the water pipe could be lower resistance than the earthing, however the pipe has to connect to the earthing bond of the transformer to make a circuit, no way can it be lower as it is connecting to the same bonding on the transformer. It can be equal to the earthing or higher but not lower
We can't allow bonding to cover poor installation. You might as well say we can't allow seatbelts to cover for bad driving. Making that the dumbest statement I have heard in a while as there is a *lot* of bad installation out there, and you can't just magic it away. Besides just because it was installed correctly you cannot reasonably assume no damage will ever occur or failures happen over the life span of the installation which could reasonably expected to be decades.
I'm with you here. I understand there is no need from the introduction of a new potential, but I want to know in fault conditions that my metal pipe work is going to trigger the fault protection rather than come live.
His statement is perfectly valid. Non extraneous parts, metallic or not, dont need bonding! Please dont think you are in some way doing a better installation by applying it. Cut and pasted from the IET mythbuster series 2018: “It is easy to think that bonding such items won’t hurt even if it is not necessary, but remember that by doing so it gives rise to the possibility of exporting fault voltages throughout an installation; it could transpire to be more dangerous than not bonding in the first place.”
Personaly i would bond regardless. If there was a fault on an imersion water heater element for example that could create a hazard, the tank would be bonded by the earth on the immersion heater anyway. IMHO if its copper from the water service delivery would bond and I think most engineers would.
I *do* hope there isn't anyone out there doing any sort of installation (of anything, really) dim enough to think that a *plastic* pipe needs a bonding strap attached to it!
In a house with radiators that are plumbed with copper pipe; are the central heating water pipes bonded completely independently of the house water supply? Could disconnecting the water pipe bonding mess with the radiator bonding?
I disagree, equipotential means everything at equal potential When i did my refresher on the 16th this came up (i'm now retired), all extraneous metalwork within the building must be bonded together, that includes water and gas pipes. One example would be an installation that has a bit of age, maybe for some reason the earth became disconnected at the immersion heater, then the element bblew apart, you would have live pipework, so the bonding would prevent shocks. Case in point, your bonding strap is on the consumer side of the valve, iirc that's what the regs tells you to do, you're not earthing the water boards pipes, you're protecting the property I remember it got a bit crazy on bonding that there were special clips to go on radiators (because ptfe is an insulator), metal window frames had to be bonded, as well as the drop chains on light fittings (a physical wire soldered to each link), thanksfully there was an update to the regs, but yeah, internal pipework should be bonded together. as well as stainless steel sinks (how many people put a kettle on the draining board)
Great vid I’m sure, but things appear and one doesn’t see them appear ( or at least I didn’t ) a flash or a circle ⭕️ maybe pulsating would help the less canny amongst us, ..😊
It best to disconnect the bonding cable entirely as with no connect to earth at the water pipe it makes it worse, you then could have live cable from your CU to....you! Or your copper pipe work onwards from the MDPE....but hey if that happens you won't get limescale ?
Hooking up the bonding in the CU is one of the worst ways, in my opinion only a "crutch", a better than nothing solution. There are better methods. For example here in Germany all bonding wires go to a central "potential equalisation bar" in the house. That is hooked up directly to the PEN in the service entrance box (TN-C-S), or the earth electrode of the building (TT). In most cases you got both here, since it is mandatory to have an earth electrode here in buildings errected after 1980. Even in TN-systems. In older buildings the incoming water pipe was designed to serve as an earth electrode, but since the cities here replace their old thick cast iron piping with plastic that won't work anymore. We called that "supportive earth electrode" to keep the voltage of the PEN close to real earth potential. And it also lowers the touchable voltage in case of a PEN fault. That's what this bus bar looks like: de.wikipedia.org/wiki/Potentialausgleichsschiene#/media/Datei:Potenzialausgleichsschiene.jpg www.amazon.de/DEHN-563050-Stange-Schiene-mm2/dp/B001Z5Z0B8/ref=sr_1_3?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=3WFSDTH391HE&keywords=potentialausgleichsschiene&qid=1636401777&sprefix=potentialaus%2Caps%2C176&sr=8-3
If the bonding cable developed a fault would you, stood in shoes on your kitchen tiles, be an easier path to earth than the plastic pipework? I'm an apprentice and curious :)
@@electricalstuff259 it is about difference between you and what you are touching Vs what you touch with another part of your body....you only need 50ma across ya heart to die...the bigger path of resistance the better. Best not to touch stuff with left hand or both at same time:)
How much potential could exist if the plastic was only a couple meters long does not water within the pipehave a low enough restitance to be a path/hazard where it is then connected to the lead incomer just thenother side of the wall. The short piece of plastic isnot acting as a complete isolation from ground? So a potential could exist?
Most likely the system beit gas or electric that's heating the water will be also bonded so in affect your piping will be bonded however I would bond it anyway just in case something were to accidentally come in contact or in the future say somebody runs a new supply line in that's copper unlikely or an out outside tap with copper. But that's my opinion and I'm living in a house where there's a ton of copper piping and it's not bonded because the income is plastic.
I am aware of this before, does not sound right to me that exposed metal in a house is not bonded, most houses will have a boiler of some description, chances are the water pipes will pick up an earth anyway. You mention we cannot allow for bad workmanship that say a cable melted and made the metal work live to be an excuse, yet we have all sorts of safety measures in place to stop electric shock, mmm not convinced.
It's not even anything to do with cables contacting pipes, safety devices in the DB will deal with that, its about lightning strikes more than anything.
Does this still apply when these water pipes are surface mounted on walls throughout an installation and include outside taps and electric water heaters? As exposed conductive parts, there is no question that they shouldn't become live, but what does the term 'under fault conditions' apply to? (Have bonded pipes in an installation like this recently)
Looks like a lot of folk got tripped up with the "You can't apply bonding to protect from faulty installation elsewhere." quote. You have to remember that the original standard was an extra protection in ALREADY - it will only reduce harm in a very specific fault condition. We shouldn't pass up on a safety factor just because "someone else should be being safe" but you do have to be practical. There is absolutely no sense in arbitrarily applying safety factors to things without a clear requirement. If the standard does not *require* it and there is no practical reason to *replace* it then don't. If there's a reason above and beyond the standard and you deem it appropriate, then go for it. Otherwise you're just going down the rabbit hole of "what if" and that leads to plain idiotic stuff. I see a lot of "what if" here. Well what if the pipe leaks, should we double jacket all the pipes? Should we bond our bed frames in case I spill my water on my heated blanket? Of course not. By all means, stand by your own work and apply your own logic. But I won't advocate for willy-nilly protection applications for just in case. It can introduce more risk than it's worth. Here's a "what if" for the crowd. What if someone does a bad electrical installation and uses that ground on the sink thinking it's a good ground. The appliance faults, but not to ground, now it faults to the sink and the user is at risk of shock. Oh the "what if" crowd. Always a scenario.
My question is if the municiple side of the pipe is metal somewhere would we still not have conductivity through the water in the pipes into the earth! Thereofre metalic surfaces like water taps would still be a danger?
What's inside that pipe? Water. Is water conductive? Yes. Only pure distilled water is not a good conductor. Will there be a metallic water pipe somewhere upstream connected to earth ground? Yes, there will be. Consequently, is there a conductive path between the metallic section of pipe in your house and earth ground? Yes, across the water in the pipe. Hence, do you need bonding of the metallic section of the pipe in your house? Yes. End of lesson. Side note: electromagnetic and electrostatic charge can also be a factor that can cause a potential voltage on unearthed metalwork.
@@efixx Depending on the level of hardness - that's how many minerals are dissolved in it - from 5x10-⁴ to 5x10-² μS/cm. Enough to create a conductive path between two sections of metallic pipes. Tap water is not an isolator. Try, you'll be surprised. Grounding will also greatly reduce the possibility of galvanic corrosion in the pipes inside the house.
In the majority of cases the internal metallic pipe work would be indirectly connected to the CPC of the boiler circuit and therefore to the MET. Annoyingly this reg change came out two months after I had battled pulling in a new 15m 10mm for the missing water bond in my own house when I refurbished the kitchen, I only needed to wait a few weeks to save myself a lot of effort … 😂😂😂
I wear my seatbelt with no intention to have a crash so I'd connect it .. And seen as water is conductive what if there is a leak ? Would it then become 0v?
More electricians Q&A here 📺👉ruclips.net/p/PLmWOIPxaBWH7XMcW07S7CTQM9G-M1GHzc
late to the party, but you can't bond plastic. it's simply common sense, so you might want to do a 2 hour video on what common sense is :-D (bad danish joke)
"You can't apply bonding to protect from faulty installation elsewhere."
I wholeheartedly disagree. Workmanship is always a variable when making standards, and overlapping protections save us every day.
Not in this case
@@lhffan But, you asked what we would do. We know that there are idiots who do unsafe work. We also know that we are all human and minds do wander. On the other hand, if the fault was in the consumer unit, bonding it could make things much worse.
18th edition says no to bonding plastic incoming pipes.
btw - It’s either earthing or bonding, not earth bonding. They’re two separate functions 👍🏻
What it should say is that in that case then any metal sink or fitting should be earth bonded to a ground spike
It’s either earthing or bonding, they’re two separate functions. The sink isn’t an exposed conductive part, therefore not required to be earthed. The sink “could” be an extraneous conductive part, if so, it would therefore require protective bonding. If not, no protective bonding. There’s a test one can do to prove if something is or isn’t considered extraneous.
@@CarlCosby What is that test?
I had a thing about 15 years ago . Plastic incoming main . All the pipe work in the flat was plastic. Customer had a electric shower and complained he got a nasty shock . Shower was about 8 foot away from the incoming plastic main. Couldn’t find anything wrong on testing. It was also a intermittent thing..After a lot of head scratching it was Infact a fault on an adjacent flats water heater .The element was faulty, so was the voltage operated trip. The fault was Infact traveling through the water in the plastic pipe into my customers flat and earthing through him when he was stood in the bath using the shower..
most tradesmen round here still use copper but if it’s plastic I get them to put a small copper section in so I can earth this so this sort of thing never happens again . This was a potentially dangerous situation that no one seems to consider
In this case, was the shower unit itself, and therefore it's constituent metallic parts, not earthed?
Similar thing happened to me .. but the author of this page stated in a comment above that tap water is not the conductive .... he’s lost me there .
I live in Germany. We have TNC-S and a plastic water pipe. The pipes in the house are made of copper and are bonded to the foundation earth. The house is almost 50 years old. As far as I know, the heating engineer has requested that the earthing is available, so the earthing is not at the inlet of the pipe but on the heating system. But that doesn't matter with copper tubes.
To the “I’d bond it anyway” brigade the video clearly shows that when it’s not extraneous it’s no different to any other metalwork in the property. If you “bond it anyway” you’re going to introduce a fault current that wouldn’t otherwise exist. We’re all about keeping fault currents away from people yet bonding an irrelevant piece of metal is increasing the chances of someone coming into contact with live metalwork. Or am I missing something?
Exactly 💯 buddy. Its potentially putting someone at risk of electric shock in the event of the pipework becoming live because there would not be a return path.
@@coralbay00 so shouldn’t bonded conductive parts that are not extraneous be coded C2 or FI on an EICR?
@@squakkers probably hard to prove its not once the plumbing is fully assembled mate. Have to trust the original designer... But given some of the comments on here that's probably easier said than done.
@@squakkers it's a dark area that one. Tbh I would consult niceic (since I'm paying for 2nd opinions) and get advice if I couldn't clarify. The internal pipework throughout the building can in itself be unpredictable. Ie bathroom fitters rock in and cut into the copper slapping in plastic pipe potentially breaking continuity. Put on the spot.......I would agree C2 if certain and fi.......if uncertain.
Don't you just love earthing arrangements 🤦♂️
@@coralbay00 No! 🤣
As an apprentice, this helped me alot. More on this topic please eFIXX!!!
The plastic pipe obviously doesn't make a direct connection to earth, but what about any metal pipe fittings further down the road? At mains voltage water can act as a conductor (or we wouldn't worry about IP rating for things exposed to damp environments) so while the path to earth via the pipe itself doesn't connect to earth directly under the house, surely there's a path to earth via the water in the pipe itself?
I accept that the potential is probably a lot lower than the actual copper earth that comes into the building though, so likely wont be a problem, but I would still expect that there is the possibility of an issue there.
Exactly except bonding to the pipe would be utterly pointless but anything metal should be bonded on the water system
Demo of how little current would actually flow through the water in the pipe: ruclips.net/video/MF9DCNkaE8I/видео.html
@@simongreenidge6454 Where I do think there could be a concern is when the insulating section is very short. If there are meters of insulating pipe then the current is going to be reduced to non-hazardous levels, but if there are only a few centimeters of insulating pipe between sections of conductive pipe that could be a different matter.
If water pipe enters to the dwelling in plastic you don’t need the bonding . That is all
@@petermichaelgreen Yes, an interesting situation. This video also makes me wonder whether, in a house with a plastic incoming water supply pipe; does any of the network of copper water pipe within the house be (supplementally) bonded e.g. the bathroom?
There's one more issue: The whole house is at "real earth" potential unless it's built on plastic foundations. Usually that doesn't matter, plaster, bricks and carpet aren't good conductors and the area we touch them is quite small. But now you have copper pipe through your whole house that is buried in brickwork. It makes contact over a quite large surface, plenty of parallel paths---and Ohm's law on parallel connections starts to raise its head.
I'd recommend to measure the resistance between "real ground" and any touchable metallic object to decide if it should be bonded.
Yeah and if you do bond onto plastic water pipe (but a piece is in copper) what about the millions of gallons of water in the pipe, no one mentions this.... What do you think
@@michaelherbert2982 Unless your city pumps you seawater, it won't conduct anything through the plastic pipes.
@@tomcapon4447 But Tom... I got 15mm copper pipe then going to plastic.... But its full of water... Millions apon millions of gallons of water... So it won't travel through that?
@@michaelherbert2982 water is a awful conductor.
@@tomorichard pure water is a bad conductor but your tap water is a pretty good conductor (because it's nowhere near pure).
On a brand new install i would accept the non-bonding of plastic incoming water pipes ( what about plastic gas pipes then ? )
Existing installs can and do bring the risks of cables being found under floors etc resting on metal heating pipes etc ( but they could now be all plastic !)
The discussion on protecting metal sinks on older BS7671 regs brought similar conflicting views didnt it ?
Personally, I'd still bond and do continuity tests to verify integrity.
"We can't bond just to cover poor installation" This is a correct statement... However.
I was receiving shocks and tingles from my New washing machine and kitchen sink, turns out Mice had chewed through the Flex feeding the washer.
This left the live conductor touching the water feed pipe and therefore livened-up the whole unbonded house water installation.
Makes you think ?
Sounds like your metal pipes had no earth.
There is a difference between grounding and bonding. The washing machine should have a proper ground wire that is wired to house grounded system. The flex cover should be bonded too.
Joe you cannot state that if the service pipework is plastic then it does not require main equipotential bonding. It is possible that elsewhere within the property that the installation copper pipework enters the true earth and comes back up again, and therefore can be deemed extraneous. A simple test to prove is what I do,....continuity test between the MET and the pipework. If the reading is
Regulation 411.3.1.2 states it. If the metal pipe enters the ground as you've described then it's a different situation and may well need a bond, if it changes to plastic where it enters and exits the ground it won't. I know what you're saying though Andrew and there'll be much more information on this subject on the way. 😊
Even if it doesn't enter earth and rise again the point of bonding is nothing to do with that.
@@asp217 sure I fixed it for you seeing as you can't read!
Interesting video, but I suspect the more complex answer is "it depends". You're only considering the water supply as it enters the building. What if some of the copper is in contact with the earth elsewhere, e.g. a kitchen island? If you can guarantee that it's not, that there is probably more danger of metallic parts becoming live under fault conditions if they were bonded. However, it's also very likely that a boiler (for example) will have all the metallic pipework bonded, so the point is probably moot anyway. If in doubt measure it, and make a decision based on that.
This literally came up on r/electricians this week. Pipes not bonded at entry, shorted to hot through a stray wire, and now all the fixtures in the house have live voltage on them relative to anything plugged into an electrical outlet.
@@tomcapon4447 Which is why we have everything behind a GFCI in the Netherlands and not only bathrooms or only sockets.
@@FoodOnCrack That’s how it is in the U.K. too.
would the dpm in the floor act as an insulator to avoid contact with earth, plus you would use plastic pipes to an island to avoid the corrosion of copper , simple answer cross bond gas water and heating pipes
actually, the issue with metal piping in the ground is just the opposite. the earth is NOT a low impedance path to ground, and the bonding network is. so by bonding metal service piping, you are bringing that piping to the same potential as your ground reference. it's not such a big deal with household voltages, but you can get a palpable voltage gradient if distribution voltage starts leaking to ground.
in the US, the relevant clause in the code is to the effect of, metal piping must be bonded if there is a possibility of it becoming energized. the usual interpretation of that is that a metal fitting under a sink is not likely to be energized unless it is connected to an appliance - and the appliance will be bonded, so there you have it.
I knew it!!! I thought it did not make sense when my electrician said my incoming water mains must be bonded even though it comes through MDPE pipe. Glad this video sorts it out!
In one job the guy came to change the gas meter, saying where is the earth cable to the water stop cock. We told him it is not needed as it was plastic. He left not doing the job. As he was leaving we called him an incompetent lazy ****. We kicked up about it and in also stated it was not needed quoting the reg. And not to send back this incompetent idiot. They apologised sending a different guy.
@@johnburns4017 You sound delightful
It’s recommended to still bond if the rest of the installation is all metalwork. What he said in the video about cables being spaced away from pipes is just wishful thinking.
Look under your floor boards, cables wrapped around pipes is basically guaranteed, check your boiler, immersion heater, appliance cables behind sinks etc. You’d be deluded if you think everything’s a1 just because you can’t see it.
@@James_scott86
I do not tolerate idiots.
@@Chris-gt3rs
With RCDs and RCBOs the need to bond a pipe not connected to earth disappears. No need.
As was stated you do not design a system expecting it to be a cowboy job.
Since the city water is conductive enough to prevent static charge from building up with a non-conductive pipe it's not necessary, but if the pipe were transferring a non-conductive fluid such as oil or gas, absolutely ground both ends of it as the friction between the non-conductive pipe and the flowing non-conductive fluid builds up a static charge.
Any working fluid through a closed isolated loop will exhibit some potential...
@@davidhilton7780 yes absolutely, but any conductivity in the fluid will drain the charge away, but of course with enough friction and not enough conductivity you can get a charge building faster than it dissipates.
@@TurboBaldur so wouldn't bonding both ends of a non-conducting line to conductive ends safely dissipate the static in the line and reduce the risks...
Thanks for your input, I enjoy it greatly. And thank you for conversation on something as trivial as bonding.
Once the metal pipework enters a class 1 appliance, like a water heater or central heating boiler, it will likely get bonded anyway via the chassis being earthed.
what about when the ground cable of the appliance /socket get disconected
@@TheMakyato How would this happen?
@@Orgakoyd by human error or accident , in europe can happen especially with boilers or washing machine . sometimes you can get electrcuted just on the wet floor
There is the electrostatic potential, and the flow of water can still give a little charge. I have seen dust cling to plastic water pipes in use, although current is minimal the field is quite large.
I find the fact that this video even needs to exist and many of the comments concerning.
Most of what I was going to say has been covered below, especially Tom Capons post, but all you need to do is ask a simple question. Will bonding it make the installation less safe? obviously not, Will bonding make the installation more safe in the event of a fault? Yes it will, so you put it back. you do not know that plastic pipe has not been installed elswhere in the building that has isolated this part of the conductive pipework from other bonding at boilers, immersion heaters etc. Regs are there to provide safety( or used to be!), It is the engineers job to ensure safety, not the regs, and anything done to enhance safety is good. Mere compliance is not good enough, just an A*se covering excercise. The attitude that," the regs say I dont have to do it so I won't" is what kills people. I was trained on IEE 14th metric 1970 and have CGND Electrical Engineering. I am afraid I have little faith in the IET as the regs are difficult to understand, contradictory, and open to interpretation, which the IEE regs were not. We were trained on every regulation till we had been through the entire book TWICE, and then examined. You were allowed one retake if you failed, and then you were out of the college, and out of the industry, today, everyone passes
Totally agree about the regs. Continual incremental changes to generate more revenue for themselves and their manufacturer sponsors. The whole book needs a complete revision with thorough proof reading to eliminate the confusing terminology (who thought up the distinctions between extraneous/exposed/equipotential ! ) and numerous ambiguous contradictions. And why the need to change section numbers at all - as if there were not enough subsection levels?
I am not an electrician, but part of my job in an electronics based industry included reviewing technical specifications of the same order of complexity and detail as bs7671, though not usually so long.
At best the section as a whole is made AMBIGUOUS by the second line you highlighted. At worst, it lures you into taking the second highlighted part to trump the first.
My department would have asked for it to be rewritten to remove the ambiguity, if it was a specification of ours! Electricians take it to mean no need to bond if the water incomer is plastic, but I read it as meaning this:
"If you have metal water main coming from the ground but a plastic stopcock or the like interrupts the conductive path, there is no need ALSO to bond the metal part rising from the ground, on the supply side of the break. Only bond the metalwork on the consumers side of the insulating break"
The purpose is equipotential bonding. It says so in the heading. If you don't bond the water pipes, etc, you do not HAVE equipotential bonding. My interpretation - that you don't ALSO bond the little bit coming from the ground resolves the apparent conflict. BUT IT NEEDS A REWRITE!
In almost every case this piece of pipe at "true ground" will not be more than a few inches long. The context is important, too. It is about EQUIPOTENTIAL bonding. A fridge next to a radiator will be connected to the CPC. It is logical that the radiator too is at the same potential, possibly even if a PEN fault has developed. That is what I take "equipotential" to mean. If you do not bond the pipes then the scenario you kind of dismissed might arise, that a fault - or dodgy workmanship - might cause a potential difference between metal cases of class 1 electrical equipment and nearby radiators, gas pipes, structural steel etc.
Bond it so you don't have an argument when ev installer comes round and does a quick check. 🤣
My ev charger was installed today, but it won't be remotely activated until i get the bonding done 😒
😂so true half a idea is dangerous
Like someone else has said I wondered about the water conducting. I am not an electrician, but have this question which many DIYers must have come across. Metal pipe into the house and to the sink with bonding at the taps. Kitchen redone with all plastic plumbing from the point the water comes into the kitchen. Stainless steel sink fitted with metal taps, but plastic tails and plastic as far as the kitchen door. I assumed that because the sink is insulated now there was no point in any sort of bonding. In fact even when there was bonding I was never sure of the logic on a metal sink. I sort of thought I understood on a plastic or pot one that connecting the hot pipe to the cold gave a route back to earth so that seemed sensible.
I’ve dealt with a live gas main entering properties, it’s scary stuff, deffo bond.
Gas in Plastic?
@@scottrobinson5594 Yup, it works just as good as metal.
We do the main bonding usually in the hot press in Ireland, under the sink would be supplementary bonding to the sink, but in the new regs due to lack of bonding points, ie no flange on sinks plastic pipes and flexible braided pipes. if we prove there's no earth path we don't have to bond, ie via insulation test .
I've always been puzzled about bonding, the reason being, every piece of metal pipework is connected to a CPC, maybe not, but I can't think of the scenario when that's not the case. If you have a gas supply and boiler, the CPC for the boiler connects any metal pipework to earth as would any water heater. A gas boiler connects the CPC to both the water and gas, though I do seem to remember that some boiler manufactures don't do this, I'm not certain of that. When the water companies changed the network to plastic a lot of older properties lost their earthing system all together, as it used to be common practice to use the water pipe as very reliable earth. There are thousands of properties, especially older ones that no longer have a proper earthing system. Why aren't there dead people everywhere due to this issue?? Totally agree that there's no point bonding metallic pipework if the incoming pipes are plastic. Great video and thank you.
All very good points, any metal work that does need bonding will need a bigger cable than most CPCs provide though. Stay tuned for more!
@@efixx Thank you for replying, when you say most CPC's will need a bigger cable it would depend how the earth fault was initiated. The adiabatic equation proves that most CPC's can withstand a far higher fault current than the protective device will let through. Food for thought.
The need for good grounding is to trip the breaker at a fault. The safety of the house comes from having one single potential on all toucheble surfaces. If all metal pipes, electrical enclosures and house frames are bonded you will not get electicuted even at a fault. No need for good earthing 😀.
@@J0nny61 we are not concerned with an internal earth fault when we talk about main bonding. We are concerned about bringing all extraneous metalwork to the same potential as the installation earth. The bonding conductor will be sized to cater for diverted neutral currents
It's correct name is equipotential bonding. Why? Because all points are at the same potential.
Let's not get confused between earthing which CPC's are for, and bonding. They fulfil two different requirements.
My boilers gas pipe will bond the water pipes but this may give a potential difference as it's not as direct as bonding the water pipes directly. This applies to indirect earth connections via an immersion heater, the motorised valves, a waste disposal etc etc. The pipes to radiators or an outside tap may also be contacting the ground at various points so I think pipes should be bonded regardless to assure continuity of earth protection, seems daft not to.
The gas pipe might be bonded but why does putting supplementary bonding on water at point of entry help?
If you need supplementary bonding - which given exemption for RCD protected circuits you can't imagine how you ever would in a modern domestic installation - then you'd install the supplementary bonding in the bathroom not at the stopcock.
Agree with this video but for some reason I still would prefer to bond it. Plus, isn't water conductive and technically there is a solid H2O conductor running inside the pipe which at some point will be in contact to earth via a pumping station, long shit yes but I don't entirely agree that your copper pipe is entirely insulated because you have plastic pipe. Who knows what's underground a few hundred yards away.
I'm not knocking your video, you are correct, just old habits are hard to remove from the older generation.
👍👍👍👍👍
That's why you should test it...
it conducts, but if you do the maths with the equivalent resistors all is well, maybe he should do the video with the detailed maths.
@@sm1thers no. Just measure the resistance of the part for goodness sake. If it's greater than 23kiloohms it's not extraneous. Possibly lower depending on circumstance.... No complex maths... Just knowing how to do your job.
I would bond internal metallic pipes because of the risk of they being in contact to the line conductors at some point. That should not happen in a well done electrical installation, but accidents happen and there are bad electricians who will leave wires exposed near metallic pipes.
This is to assume that the only connection point between the ground and the water pipe is the incoming pipe. An underground feed in conductive piping to a garden tap or outbuilding would do the same thing. There may be other possibilities too, whereby the property's internal conductive pipework has a connection to the ground. It may be rare, but it surprises me that it is not mentioned in the regs as a possibility.
Of course, the most likely way that the copper piping would have a connection to the ground would be via a gas boiler if the incoming gas supply is via conductive pipe, but then the bonding on that ought to deal with the situation.
In the US it does require bonding. The water in the pipe is not pure, therefore it is conductive. It goes through a metal pipe in the earth somewhere. That is why we ensure all metal pipes are bonded on the US. If metal water pipes are separated by plastic pipe we have to bond both sections.
Note to those who would argue with me about the water not being pure: When I say it is not pure I am not talking about how safe it is to drink. Safe to drink is a different metric as compared to purity. Tap water contains minerals. It is not pure H2O until it is distilled. All drinking water and residential tap water has minerals in it.
My thought is the pipe should be bonded as soon as it turns to metal inside the house;
Reasons
1-Do you know the whole supply pipe is plastic?
2-i have seen supply pipes where the last foot has been converted to plastic but the rest underground is metal. I know tap water has a quite a high resistance per metre inside plastic but it would still provide a conductive path.
3-What if something is changed in the future and ended up grounding your copper pipes. Better to locate the cable & clamp than do it at a later date.
Yeah. If you earth something that doesn't need to be earthed, ( as you said bedframe), then that creates a dangerous situation, because now if you touch something live, and that earthed object, the current will shoot through you.
Yur, could be dangerous.
But that is why we have RCDs now.
@@davepusey RCD will reduce the level of electrical shock that you may get. But you'll still get a belt but for a shortish period of time.
RCDs used for protection on sockets are rated at 30mA. Studies have shown that 'usually' the heart needs over 40mA for 200mSec to go into fibrulation so it is calculated that 30mA will give a reasonable level of protection.
They are not a catch all 100% safety blanket. they are an electro-mechanical device and (as such) can go wrong - that's why they need to be tested every 3 months.
If anyone disagrees, how about standing on a wet floor, and put your tongue on a live cable.
if you are reading from an old code book it may be required in the updated book.
if you are reading from a new book then it may have been required and discontinued.
the only reasons i can think of why to bond plastic pipes os.
1. a financial kickback the more stuff you have to install the more the industry makes money so maybe grounding wire and clamps cost money and it was done for money.
2. static charge certain contents may cause static build up so it was done to bleed off static.
3. ground loops if there is a section of plastic between 2 metal pipes it is to keep all the metal sections at the same level.
4. plumber was out of pipe clamps so he used an electrical clamp but if that is the case there should be no reason to connect a grounding wire.
unless the code book sais that any electrical clamp in the system has to be grounded.
JOe's analysis of the potential between the neutral at the entrance and the grounding conductor at the transformer is a bit hyperbolic. In the US NEC, there shall be a local grounding conductor in contact with the earth and connected to the ground potential terminal in the breaker box (that is the Green conductor). Bonding to the incoming water supply pipe is one method of creating a grounding connection. Other methods are to connect the earthing conductor to a grounding rod of at least 8 feet (3 meters) driven into the ground, or the attach the conductor to the metal reinforcing rods in the concrete of the foundation. (Ref. NEC-1999 article 250-C). Any non-conductive pipe shall be bridged across from the grounding electrode to the metallic interior pipes, and the exterior grounding water pipe shall be in direct contact with the earth for 3.05 meters. There is another regulation in the IRC abound the distance from the entrance of the metallic pipe to the electrical earthing conductor.
I heard about an EICR recently that had missing earth bonding labelled as a C1. Tennants had to be relocated as the rental agency freaked out. Shocking!
A missing bond is a C1? Thats crazy.
@@alouisschafer7212 i agree its not immediately dangerous
Your tutorials are excellent.
Interesting, I have a blue feed pipe and have earthed internal pipping but was told to also earth stake the internal side of the stopcock with 16mm.
This video got me thinking, I had wanted to run a soft copper insulated radiator supply a short distance to the garage in the ground, & the boiler is external oil but the oil supply pipe does already run in the ground !!! This is going to be sleeved in the future but never the less getting wet. & what about old house pipes that in concrete floors. The supply in is overhead line & earth with a main RCD.
In The Netherlands every home has there own earth-rod connection to the earth.
The water inside the pipe may be conductive as well. Therefore inside a bathroom a metal schowerdrain, a metal radiator, warter-taps etc etc are bonded to an earth-wire as well.
In older houses with wooden floors, where there is a steel floor-support (in concrete on top of the wooden floor), the steel is earth-wired as well.
Is that different form the UK?
Yes, most connections in the uk, except for a few rural properties have either a separate earth connection from the local distribution, or an earth connection which is tapped off the neutral as it enters the property (and the neutral is regularly earthed along its path from the transformer to the property). Bonding varies depending on the age of the property and what wiring regs were being worked to. Building metalwork is also bonded, but steelwork is not very common in uk homes (it’s only usually in one off type builds or commercial buildings). It’s amazing to see how differently different countries approach the same problems.
My house has plastic pipes coming in, but I don't know that there aren't any parts of the internal metalwork touching anything conductive that's in the ground... In fact I'm pretty sure that the metal pipe to the oil tank will be connected through the combi-boiler. This old install is bonded and I'm keen to keep it that way
I also have plants touching my outside tap
Agreed, no need to bond, no point at all.
I have a new build, plastic pipe and bonded anyway, I thought builders were all about saving any money they could?!?
Misinterpretation of regulations is a really big problem - they're written awfully and sometimes the training is just as bad.
Quite often I come across Radio Hams on a TNCS system, but with their own "RF" eath that can be anything from and aditional earth rod of some description driven into the ground to a whole scrap car buried in the garden. Some are insistant that the RF and Mains earths have to be isolated from each other, some ask why a multimeter shows a voltage difference between them, and some will actualy allow a bonding connection between them. I always suggest that the RF earth can be improved by linking them and quote ohms law :)
Hi Steve, I qualified as a radio Ham a long time ago.
Separate “Earths” for power supply (mains) and Radio Frequency (RF)
The mains Earth (CPC) is for protection from electric shock and for removal of power under fault conditions. This Earth can cause noise to be introduced into circuits from switch mode power supplies and power line adapters etc.,
RF Earth is to provide a low noise reference to incoming signals to the receiver and to provide a separate Earth for the transmitter aerial which is outputting considerable radio frequency currents. The RF Earth, very often, is part of the aerial system. There would be problems if this high power RF current was connected into the house wiring via the Earth (CPC).
Ham radio equipment has a special “Earth” terminal for RF.
Ham radio equipment manufacturers advise not connecting to the mains Earth (CPC). I do not transmit but just listen and all of my receiving equipment has this advice.
@@dougmorris2134 The definition of an extraneous-conductive-part as defined within BS 7671:2018 is as follows: “A conductive part liable to introduce a potential, generally Earth potential, and not forming part of the electrical installation.” ... Not forming part of the electrical installation.
Your RF earth requires bonding :(
bonding is there for failure a broken element in your boiler can create the whole thing to come live .. if lightning hits pipework in your loft it needs to go to ground... a modern house were all the pipeworks made out of plastic I will agree.. what your showing needs bonding
Hi Joe, I would still bond! The reason being that as water isteslf conducts electricity it becomes a return path and thefore a potential difference to the installations 'earth' value as regards an equipotential difference! Regards David
The plastic water pipe is only isolated when it is dry, otherwise it is connected to ground through the water within it so any metal pipe connected to this plastic water supply pipe is grounded through the water itself to nearest conductive pipework in the ground.
A ground can also be formed through a water leak. If there was a fault applying a voltage to metal pipework connected to a plastic water main there may appear to be no problem until one day there is a leak and the pipework is now effectively grounded creating a return path. This leads to a situation where it could be rather difficult to determine why breakers suddenly start tripping for seemingly no reason (possibly intermittently), people suddenly getting electric shocks in the bath or shower with seemingly no apparent fault and other anomalies. Whereas if the metal pipework was grounded the fault would be apparent straight away and not seem to disappear and then return as well as there being a ground connection that could me tested for current flow which would drastically increase the possibility of diagnosis in a timely manner and genuinely protect peoples lives.
Commenting from the other side of the pond, there are benefits to bonding sink piping and fixtures to earth. Customer safety. Bathrooms/washrooms have a GFCI receptacle for personal safety if a hair dryer or electric appliance fall into a sink full of water. If the metal faucet fixtures are not bonded, (PVC DWV pipe and/or pex/CPVC supply lines) the electrified water has no discharge path except thru the person to the floor. If the faucet, sink and flex piping is bonded to earth, the GFCI will sense the fault and trip. Without the fault, the gfci will happily keep the appliance electrified and running since the electricity is flowing into and out of the device as planned-no fault, but a deadly condition still exists if a customer reaches into the sink to pull out the device. There are videos where electricians have turned on hair dryers, dropped them into a sink filled with water and the appliance happily keeps running since no fault current is detected by either the socket's GFCI nor the device's GFCI plug.
I'm not familiar with UK RCDs to know if they will detect this condition and protect occupants in the same way.
This analysis is wrong.
Consider the scenario where there is no bonding and a GFCI is present.
If the customer reaches into the sink and there is a dangerously high potential present, the customers body acts as a resistance to earth and current starts to flow through them. The live and neutral currents are no longer the same and the GFCI trips, cutting the power off and preventing electrocution.
Dropping a hair dryer in to the water in the sink with the hairdryer switched on doesn't result in the GFCI tripping because the live and neutral currents are the same, there is no path to earth. The porcelain of the sink is an insulator . As soon you put your hand into that water, there is a path to earth through your body, there is potential across your body, and that potential difference starts to cause a current to flow through it, which now means the live and neutral currents are no longer the same, and hence the GFCI trips.
So yes, placing a hair dryer into water creates a dangerous situation, but the GFCI will prevent the person being electrocuted.
Earth bonding the metal water outlet pipe and the metal plug hole (if it is made of metal) does help, as it should (not guaranteed) cause the circuit breaker in the consumer unit/distribution board to trip.
But the safest way to prevent electrocution is through the use of the GFCI.
If the outlet pipe is plastic then bonding it is pointless as it is not conductive (except at very high voltages!)
What if there is a bond wire to the cold water pipe inside the apartment. At some point, the plumber replaced the feeder pipe with PEX. Is there an easy way to check whether that was the main earth ground of the apartment, and would it need to be rebonded or to add earthing rods?
Good video, ta. I'd bond it, I've just been in a house where the owner drilled a cable (but didn't realise it at the time) when fitting his metal curtain tie backs. The tie back was lightly touching a painted central heating pipe, which was sitting at about 190v to earth. The reason I was called was that he was getting shocks in the shower. Neither the mcb or rcd was tripping ( no idea why, the rcd tested ok). If it had been properly bonded, it would have tripped. It had been like this for about 2 months!
Good day this is Mike from Amsterdam Holland we got the same problem here but the regulations are you have to bond your tube because when it conduisait it will still conduct the bonding
More vids from under the sink please, this could be a feature
😂 good idea 👍
Even tho the water pipe entry is plastic, the copper pipes in the house come into contact with all sorts and if you measure a resistance to earth, then it may need bonding.
Here in Germany it's different. The incoming gas pipe is usually plastic, after the meter usually metal. You'll have to bond that metal part. Copper piping for the radiators -> bond. Shield of incoming antenna cable (cable TV or satellite) -> bond. If the incoming gas pipe is metal and has one of these short plastic pipes in between as an electric isolator you are only permitted to bond the pipe after that isolator. If you want to bond the part before the plastic isolator you'll have to implement SPD into the bonding wire.
Until 2003 we even bonded metal bath tubs and shower trays because they were considered as being extraneous conductive parts. And they still have the terminal for a bonding wire today, for in case you install it in old installation. Because there you'll have to bond it again with at least 6mm² copper wire.
That was because the original waste pipe was maybe metal and was outside,so extraneous and could be liable to lightening strikes?
@@สมบัติสตีเวนสัน-น6ษ Maybe, but cast iron drain pipes were state of the art during the 1950s. Later in newer constuctions replaced by non-conductive glazed ceramic pipes, and then again by plastic pipes. Inside of the building polypropylene and outside PVC-U (unplasticized PVC). The PP can handle higher temperatures better than the PVC and is also more resistant against corrosive chemicals like detergents from dishwashers and washing machines. But the PP can't handle to be buried directly into the ground, you either use the PVC or embed them into concrete t reduce the pressure caused by the soil it's embedded into. For easier determination the PP pipes are grey and the PVC ones are orange or brown.
I've seen a voltage difference between cold and hot pipes within a house form when the hot water pipe heats up as a tap opens.
I'm just wondering if in future a reg will come out with a bonding portion of pipe to bring the water to a zero potential.
3:12 "And because fault current is usually quite high, the voltage pushing it along can get quite high too". Apologies if I've interpreted this incorrectly, but the fault current will only be high if the voltage, or the potential, is high. The resistance between the fault and the ground source will dictate the voltage and thus the current.
My understanding of equipotential bonding was also to do with the potential influence of other phases within the area. eg, the neighbours house could be on L2 whereas my house is on L3. A fault on their shower could introduce a potential between close pipework and a grounded receptacle in my house. In other words, it ensures that all potential fault currents across the area have a common (neutral) path to the center point of the transformer.
Almost right on the first point (unless you want to get into quantum mechanical explanations of electromagnetism). It takes a voltage to drive a current. BUT don't forget there is a current in the supply side too, so that drops a voltage; the voltage at the fault point is based on the ratio of the resistances on both paths to the transformer. Assuming (!) they are the same, the voltage would be about half the expected supply voltage. Slightly less resistance in the return path, and the voltage will be slightly lower than half.
Depends on what sort of floor the house has, if it's soil under boards like in an old terrace, there's a chance of pipes resting on the soil even if the income is pvc. Then there's a chance of the floor being unfilled and concerted to stop pooling surface water on the surface.
My plumber fitted a new stop tap, he used a plastic push fit connector onto the main water feed in then copper pipe then stop tap as it was live when he changed it. He left the bonding wire disconnected. Now because I have a plastic connector between the main feed and the house pipe work does it still need bonding as the old wire doesn’t reach to what’s left of the inlet feed pipe
I think a return to the physics lab might be in order. Some interesting experiments in contact with water from metal and then water in MDPE which may or maynot be a presurised pipe or empty from water completely! Earthing, bonding and a mix and match of both people like to use is not the answer to all situations. Let's go back to oil lamps and candles and avoid the electric shock but careful not to burn your house down :)
That took a turn towards the end there Sean! 😂
From another country so please excuse my ignorance, but given the water is conductive enough to cause electrocution and is likely contacting the literal earth just outside the property at the next metal fitting and thus has potential, why would you not bond it anyway to ensure no potential shocks? In my country our version of TN-C-S also adds an earthing steak at the property to help prevent this situation.
If you have disconnected all your bonds from the incoming water supply you can test this by checking the voltage potential from both your taps and electrical Earth.
I'm also surprised you don't have an earth steak, what would happen if you touched a metal exterior wall mounted light and the literal earth in the rain?
I would leave a earth bond floating around the incoming water on a new rewire just incase there is some major change to the water supply...unlikely but the hassle of not having it around is more...
But not connect... and just leave in board but mark it not connected...
Depends lots of variables..
I'd bond it anyway because you have no way of knowing if the homeowner has installed a metal pipe elsewhere that exits the building, to an outhouse etc. If there was no plastic between that and the incoming metal stopcock then the pipework would then all be at earth potential. You could argue that that shouldn't happen but it's unlikely that a home diyer or plumber would consider that and possibly neither should they have to - it's the electrician's job to ascertain that and plan ahead for it.
You mentioned a possibly scenario for not including bonding because it shouldn't be relied upon to prevent danger where other regs have been violated but then surely that is the same for a metal pipe coming in. The earth bonding is there to provide a path back to the panel in the case of a fault which could occur even with a plastic pipe entering, such as driving a nail through a pipe and cable at the same time... I'd say the difference would be that the bed can be moved but the pipework cannot be so should be bonded. You could argue though that the bonding could occur at the most convenient location and not necessarily within the regs distance of entry to the building...
When the main water pipe is metal and the internal pipes are plastic, which is quite common, the few inches of metal pipe into the house needs bonding.
MDPE mains supply pipe fittings could incorporate a moulded Brass metallic earth fitting easily to overcome these issues
Is there a potential for the current travelling through the water of the plastic pipe until it meets a metal pipe that’s buried underground?
Totally agree, bonding is not needed. Water in the pipe really is a poor conductor - not enough ions in it, so quite high resistance path - higher than the alternative (wiring), or if it were in a metal pipe (copper, iron etc). One minor comment, the two earth points will not always be at the same potential ("0v"); I don't recommend measuring unless in a very controlled environment, but if you disconnect ALL the bonding and measure during a thunderstorm, you'll see the effect...and depending on local conditions, the resistance can be low enough for a respectable current (or can be just potential).
Definitely earth it. I have just discovered my stopcock was live due to fault on Powergrid cable making my earth rod live. Powergrid told me the water pipe should be earthed but the supply pipe installer failed to tell me.
So if your earth rod is live and you also earth the water is that not live too? If it’s plastic then it can’t become live, the only way it can become live is if you then earth the copper pipe.
@@DTech101The water was live, cooper pipework, taps, bath, all metal surfaces including radiators. They tell me it's now repaired as they've replaced the 90 year old box on the utility pole and part of the cable but I'm terrified!!
@@loriAlessiroberts118 unfortunately nothing you can do about there side only your side, but that should be good for years now
@@DTech101 Yes there was nothing wrong with my side it was their equipment energizing the lead on my supply cable, but they've confused me by saying my water pipe should be earthed also. I've since been told that wouldn't have made any difference as the earth rod was energized.
My home in the US has plastic PEX piping and it is not bonded to the electrical service ground. Code does not require it. However, water is a conductor and water flows from buried metal pipe in the street and comes in contact with metal valves and fixtures in the home. Could a voltage potential be applied somewhere in the system, perhaps a faulty electric water heater element? Perhaps bonding at a location near the entrance via a stainless steel or brass pipe fitting might be a good idea?
The metal pipe inside the house is connected to earth through your combi boiler even if its plastic incoming.
No its not! Pipe bonding shouldn't be anywhere near supply cables. They are two completely different and separate circuits!
@@stuartcraigon2003 your combi boiler is earthed through the spur , so you have continuity through the combi boiler to the internal copper water pipe , so your potential on the copper water pipe has a potential of 0V, even if incoming water is plastic.
Unless the incoming water supply is demineralised water then it will be conductive (If there were any more minerals in our hard water local supply, it would be supplied in sacks). Regardless of the entry to the house, some of the downstream supply pipework may be metal anyway so there is possibly still a risk. Has there been any investigation as to this being credible?
Edit:- I have read some more of the earlier comments regarding water being conductive and I would add this observation based on my experiences in power stations- Demineralised water is non conductive, in fact it is used to cool HV stator windings in large alternators. Insulating pipework lies between the windings and the pumps.
However, town water supply is conductive otherwise the electrode boiler (that was used for emergency use in part of the plant) would not work, as it depended on high currents passing through the water within.
My personal choice would be to bond anyway, as the IET rules on earthing seem to change rather often.
The main water supply have probably something, somewhere, metallic (an older pipe, a shutoff valve, etc) touching the water inside the pipe, and the earth outside the pipe. So the water is touching the earth via this part. Then if you have something metallic in your installation inside the house, touching the water, a faucet, a valve, a pipe, then this metallic part is touching the earth too, via the water that is touching the metallic part outside, that is touching the earth... 🤷🏻
How about this scenario, “a non extraneous” water pipe with an insulating section at its point of entry doesn’t require a main equipotential bond. So what about when this turns internally into a copper water pipe installation, then this copper pipe is installed into a metallic boiler manifold. Then this manifold connects to the extraneous gas pipe work (with a metallic section at its point of entry) surely now this “common” copper pipe work is now deemed to be extraneous???? And how the hell do you successfully perform a 22K test on “commoned up” gas and water copper pipe work installation? 🤷♂️
you would bond the main incoming gas in that case as that is still incoming to the property
@@markpotter8280 yes I agree but the extraneous gas pipe work is making the non extraneous water, an extraneous conductive part, and there’s no way of separating the two.
Go to 1:08; it says "Metallic pipes entering the building having an insulating section at their point of entry need not be connected to the PEB." - ie; you do not have to bond to the utility company's incoming metal pipe, should it exist.
The clue is in the words: "Metallic pipes entering the building". You have a plastic pipe entering the building.
Section (i) 5 lines above it says: "Water installation pipes".
That includes all metalwork connected to the water pipes on your side of the plastic building-entry pipe.
Here is a sample reason for earthing all metallic parts:
If you have a fault in your immersion heater/water heater/pump etc, it will render the entire house heating-system live, radiators and all if it is not bonded. Read the rules, they are there for your protection!
The same reg states that the metal water pipes will need bonding if they are extraneous conductive parts. If they're not introducing 0v potential they're not extraneous and won't need bonding. It's not being a water pipe that makes it need bonding it's being an extraneous conductive part.
I would still bond if it’s an existing installation or pipework. Somewhere on the pipework could be bonded to earth but not the rest of the cpc
A PEN fault will promote an alternative return path for neutral current through any extraneous earth connection ie metal water or gas pipes, either from the property affected or as a bypass through a property from an adjacent property on the same supply. Plastic service pipes do at least prevent a dangerous rise in main earth current due to PEN faults.
They are more common than you think - check out Team Electrical podcasts 1 and 2 on Diverted Neutral Current.
We are not taught to think critically so we expect the DNO head to be whatever it appears to be.
Today most service heads are TNC-S and not TNS because somewhere outside the property a repair to the old PILC cable will have made the supply TNC-S. The only exception might be in a rural area where supplies are mostly fed overhead.
I would bond metal pipework, There are that many metal central heating pipes and cold and hot water pipes in contact with the ground that there may be a chance that your plumbing would be in contact with the general mass of earth.
Good explanation, makes sense.
Very well put. I'm of the same mind it makes sense not to connect it but having it connected doesn't seem like it would be that much harm and would be extra insurance in-case of an unintended fault. I'm not thinking poor workmanship that should be the above all standard is that accounts for so many things. I'm thinking water heaters and boilers which are already grounded anyway having a fault or other water loving electric appliances. And well water is non-conductive in a pure state most water has some minerals in it so it wouldn't be truly nonconductive. So does this mean if I have plastic piping going to my tub I can make toast in the bath? Well apart from the GFCI/RCD.
My house has bonding in the bathroom, kitchen and down stairs loo.
But the pipe bringing in the mains eater to the d s loo is plastic.
All water supply pipes in the house are copper except the ufh on the ground floor.
So if all copper pipes have bonding but I do not believe is bonded back to ground?
So what is the point, think the house was built in the 70"s
Should I bond the nearest pipe to the supply metal protective shield, which is under the stairs and the ufh manifold 22mm copper pipes are there to approx 1 meter away.
Thanks for the thoughts on earth bonding and video.
In the USA is impossible to bond or ground anything that does not conduct electricity like plastic pipe. If you have plastic pipe feeding water to a metal kitchen sink that has plastic drain you should bond sink.
So out of interest on the EIC do you put N/A in the tick box then? Would this be sufficient or would you need to prove bonding is not necessary by providing a measured resistance value to prove it isn’t required ?
I think you're playing devils advocate here Joe!! In the video, you've completely ignored the issue of metalwork within an installation picking up an earth potential along its route by virtue of being buried in the ground, for some reason, despite it having a plastic supply - see, for example, sections 4.3 and 4.5 of the OSG.
Not intentionally John, this is the first video of many on this subject and you're quite right about pipes entering the ground elsewhere, however that would be a different situation to the one considered in this video. We'll get to other scenarios down the line. 👍
In the sketch he says the water pipe could be lower resistance than the earthing, however the pipe has to connect to the earthing bond of the transformer to make a circuit, no way can it be lower as it is connecting to the same bonding on the transformer. It can be equal to the earthing or higher but not lower
We can't allow bonding to cover poor installation. You might as well say we can't allow seatbelts to cover for bad driving. Making that the dumbest statement I have heard in a while as there is a *lot* of bad installation out there, and you can't just magic it away. Besides just because it was installed correctly you cannot reasonably assume no damage will ever occur or failures happen over the life span of the installation which could reasonably expected to be decades.
I'm with you here. I understand there is no need from the introduction of a new potential, but I want to know in fault conditions that my metal pipe work is going to trigger the fault protection rather than come live.
His statement is perfectly valid. Non extraneous parts, metallic or not, dont need bonding! Please dont think you are in some way doing a better installation by applying it.
Cut and pasted from the IET mythbuster series 2018:
“It is easy to think that bonding such items won’t hurt even if it is not necessary, but remember that by doing so it gives rise to the possibility of exporting fault voltages throughout an installation; it could transpire to be more dangerous than not bonding in the first place.”
Personaly i would bond regardless. If there was a fault on an imersion water heater element for example that could create a hazard, the tank would be bonded by the earth on the immersion heater anyway. IMHO if its copper from the water service delivery would bond and I think most engineers would.
I *do* hope there isn't anyone out there doing any sort of installation (of anything, really) dim enough to think that a *plastic* pipe needs a bonding strap attached to it!
In a house with radiators that are plumbed with copper pipe; are the central heating water pipes bonded completely independently of the house water supply? Could disconnecting the water pipe bonding mess with the radiator bonding?
If a lead water pipe was swapped out for mdpe, would bonding the old still be worth it?
In the case of an earth fault within a piece of equipment, wouldn’t there be an over current or RCD trip which removes the danger?
I disagree, equipotential means everything at equal potential
When i did my refresher on the 16th this came up (i'm now retired), all extraneous metalwork within the building must be bonded together, that includes water and gas pipes.
One example would be an installation that has a bit of age, maybe for some reason the earth became disconnected at the immersion heater, then the element bblew apart, you would have live pipework, so the bonding would prevent shocks.
Case in point, your bonding strap is on the consumer side of the valve, iirc that's what the regs tells you to do, you're not earthing the water boards pipes, you're protecting the property
I remember it got a bit crazy on bonding that there were special clips to go on radiators (because ptfe is an insulator), metal window frames had to be bonded, as well as the drop chains on light fittings (a physical wire soldered to each link), thanksfully there was an update to the regs,
but yeah, internal pipework should be bonded together. as well as stainless steel sinks (how many people put a kettle on the draining board)
So your designing for multiple faults - first the earth has disconnected then the element has failed - is that not why we have RCD protection ?
@@efixx The point is that it's equipotential bonding within the building
Great vid I’m sure, but things appear and one doesn’t see them appear ( or at least I didn’t ) a flash or a circle ⭕️ maybe pulsating would help the less canny amongst us, ..😊
It best to disconnect the bonding cable entirely as with no connect to earth at the water pipe it makes it worse, you then could have live cable from your CU to....you! Or your copper pipe work onwards from the MDPE....but hey if that happens you won't get limescale ?
Hooking up the bonding in the CU is one of the worst ways, in my opinion only a "crutch", a better than nothing solution. There are better methods. For example here in Germany all bonding wires go to a central "potential equalisation bar" in the house. That is hooked up directly to the PEN in the service entrance box (TN-C-S), or the earth electrode of the building (TT). In most cases you got both here, since it is mandatory to have an earth electrode here in buildings errected after 1980. Even in TN-systems. In older buildings the incoming water pipe was designed to serve as an earth electrode, but since the cities here replace their old thick cast iron piping with plastic that won't work anymore. We called that "supportive earth electrode" to keep the voltage of the PEN close to real earth potential. And it also lowers the touchable voltage in case of a PEN fault.
That's what this bus bar looks like:
de.wikipedia.org/wiki/Potentialausgleichsschiene#/media/Datei:Potenzialausgleichsschiene.jpg
www.amazon.de/DEHN-563050-Stange-Schiene-mm2/dp/B001Z5Z0B8/ref=sr_1_3?__mk_de_DE=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=3WFSDTH391HE&keywords=potentialausgleichsschiene&qid=1636401777&sprefix=potentialaus%2Caps%2C176&sr=8-3
If the bonding cable developed a fault would you, stood in shoes on your kitchen tiles, be an easier path to earth than the plastic pipework?
I'm an apprentice and curious :)
@@electricalstuff259 it is about difference between you and what you are touching Vs what you touch with another part of your body....you only need 50ma across ya heart to die...the bigger path of resistance the better. Best not to touch stuff with left hand or both at same time:)
@@stephencoulthard1718 Threshold for a healthy adult is 30mA, for kids and elderly people (especially with heart issues) it's even lower than that.
How much potential could exist if the plastic was only a couple meters long does not water within the pipehave a low enough restitance to be a path/hazard where it is then connected to the lead incomer just thenother side of the wall. The short piece of plastic isnot acting as a complete isolation from ground? So a potential could exist?
Most likely the system beit gas or electric that's heating the water will be also bonded so in affect your piping will be bonded however I would bond it anyway just in case something were to accidentally come in contact or in the future say somebody runs a new supply line in that's copper unlikely or an out outside tap with copper. But that's my opinion and I'm living in a house where there's a ton of copper piping and it's not bonded because the income is plastic.
I am aware of this before, does not sound right to me that exposed metal in a house is not bonded, most houses will have a boiler of some description, chances are the water pipes will pick up an earth anyway. You mention we cannot allow for bad workmanship that say a cable melted and made the metal work live to be an excuse, yet we have all sorts of safety measures in place to stop electric shock, mmm not convinced.
It's not even anything to do with cables contacting pipes, safety devices in the DB will deal with that, its about lightning strikes more than anything.
Does this still apply when these water pipes are surface mounted on walls throughout an installation and include outside taps and electric water heaters?
As exposed conductive parts, there is no question that they shouldn't become live, but what does the term 'under fault conditions' apply to?
(Have bonded pipes in an installation like this recently)
Looks like a lot of folk got tripped up with the "You can't apply bonding to protect from faulty installation elsewhere." quote. You have to remember that the original standard was an extra protection in ALREADY - it will only reduce harm in a very specific fault condition.
We shouldn't pass up on a safety factor just because "someone else should be being safe" but you do have to be practical. There is absolutely no sense in arbitrarily applying safety factors to things without a clear requirement. If the standard does not *require* it and there is no practical reason to *replace* it then don't. If there's a reason above and beyond the standard and you deem it appropriate, then go for it. Otherwise you're just going down the rabbit hole of "what if" and that leads to plain idiotic stuff. I see a lot of "what if" here. Well what if the pipe leaks, should we double jacket all the pipes? Should we bond our bed frames in case I spill my water on my heated blanket?
Of course not. By all means, stand by your own work and apply your own logic. But I won't advocate for willy-nilly protection applications for just in case. It can introduce more risk than it's worth. Here's a "what if" for the crowd. What if someone does a bad electrical installation and uses that ground on the sink thinking it's a good ground. The appliance faults, but not to ground, now it faults to the sink and the user is at risk of shock.
Oh the "what if" crowd. Always a scenario.
My question is if the municiple side of the pipe is metal somewhere would we still not have conductivity through the water in the pipes into the earth! Thereofre metalic surfaces like water taps would still be a danger?
What's inside that pipe?
Water.
Is water conductive?
Yes. Only pure distilled water is not a good conductor.
Will there be a metallic water pipe somewhere upstream connected to earth ground?
Yes, there will be.
Consequently, is there a conductive path between the metallic section of pipe in your house and earth ground?
Yes, across the water in the pipe.
Hence, do you need bonding of the metallic section of the pipe in your house?
Yes.
End of lesson.
Side note: electromagnetic and electrostatic charge can also be a factor that can cause a potential voltage on unearthed metalwork.
Tap water isn’t really that conductive
@@efixx Depending on the level of hardness - that's how many minerals are dissolved in it - from 5x10-⁴ to 5x10-² μS/cm.
Enough to create a conductive path between two sections of metallic pipes. Tap water is not an isolator.
Try, you'll be surprised.
Grounding will also greatly reduce the possibility of galvanic corrosion in the pipes inside the house.
In the majority of cases the internal metallic pipe work would be indirectly connected to the CPC of the boiler circuit and therefore to the MET.
Annoyingly this reg change came out two months after I had battled pulling in a new 15m 10mm for the missing water bond in my own house when I refurbished the kitchen, I only needed to wait a few weeks to save myself a lot of effort … 😂😂😂
Great Video
I wear my seatbelt with no intention to have a crash so I'd connect it .. And seen as water is conductive what if there is a leak ? Would it then become 0v?