METER TAILS LONGER THAN 3 METRES- Switch fuse isolators from LEWDEN
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- Опубликовано: 28 апр 2024
- If you are installing electrical meter tails longer than 3 meters long, you'll need to install a meter tail switch fuse. We explore two of the most popular options from Lewden.
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Products featured
Lewden MSF (main switch fuse)
Lewden 100A DP Switch fuse metal
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Article discussing long meter tails from Professional Electrician by Paul Chaffers NAPIT
professional-electrician.com/...
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🕐 TIME STAMPS 🕕
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00:00 Electricity meter tails longer than 3 meters
01:00 Or is it 2 meters? - ask your DNO
01:43 Plastic isolator for use inside a meter box - Lewden MSF
03:50 Option for use with Twin and Earth
04:40 Protection for longer meter tails
05:50 Switch fuse isolator for use with SWA cables
06:20 Supplied with 60, 80 & 100A fuses
07:40 Alternative cable entry option
08:50 Generous terminal sizes
09:18 The all-important torque settings
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I've installed a few of these in meter cupboards to comply with the 3m rule when doing board changes. Absolutely wonderful bit of kit, hugely flexible design.
That was very informative as we live in a flat complex of 24 flats where the meters are located in a central location with these types of isolators installed. Thanks.
at 4:15 love how the video sorta re sets where he had to find out what the cable duct was referred to as (I assume) haha. great video as always. thanks
I’ve used this lewdon switch-fuse with tails in and out and positioned it outside the meter box (meter box being inside the house). Also used the method of putting unearthed 4mm steel strip in front of the tails for protection all the way to the fusebox. Very happy with outcome.
Why wouldnt you earth it?? I used 40mm plate infront of tails and the plaster baord over and warning live cables behind bud.
The chance of drilling into 40mm steel tnat earthed is low..
@@bramcoteelectrical1088 To my mind playing hind and seek with cables is ultimately silly, regardless of what the ''appetite'' of the human race is at the moment. It is not 1890 anymore and electricity is a massive part of everyday life, yet people want the inside of their houses to look as if it's 1890 with regards to wiring and pipes. I'd say everything on surface, in cable tray or otherwise with maximum focus on ease of maintenance and accessibility. Suddenly the number of wires getting drilled or screwed into will drop to nearly zero, with the added benefit of not requiring a partial demolition to replace said cable in the rare event damage occurs. And shoddy work will be much easier to identify and fix, no more convenient hiding places for idiots who don't give a crap.
Fantastic video guy’s as always very interesting. 👍👍👍❤️⚡️
Love the lewden switch fuse best on the market
I really like the heavier duty version. that would be my pick if I was planning a electrical job. 100A main.... thats enough for any new home... here in the US, we have 100, 200, and even 400 Amp mains for the homes here... when you have a huge home with a detached garage, or even a shop.... 400 amp is the way to go here.... love the video! thanks guys!
Your information is good, thank you
I am so glad to see this Video I am have this issue on a new build. Where the contractor who did the original install is saying there is no regulations to state that the meter tails should not be only three meters long stating the NICEIC are happy with this. I am also a NICEIC contractor I have challenged this with the relevant regulations. The tails they have installed is 7 meters long and run thought the property.
You should watch this video to see how the regulations cover this - ruclips.net/video/iR-xYgBuDgo/видео.html
@@efixx Thank you i stated these regulation in my letter to the contactor. But they are having non of it. I will have yo contact the NICEIC to see if they can help. I am doing this for my customer its a new build and they have only been in a month.
Nice designs by Lewden there.
Great video guys 😎
Fitted one today, fusebox do one virtually identical too. 16mm armoured for a sub main
Lewden's "Cable duct" is usually referred to as a spreader box, at least with larger switchgear
Great video as always, shame 90% of new builds have tails longer than 3m which are being signed off.
I am having the same problem with a new build. Trying to get them to come back is a joke.
I had the same issue with mine, took a complaint to the NICEIC before it was sorted. Even then, the NIC inspector took some convincing that a) 3m was a rule and that b) the tails were deffiantely more than 3m despite the meter being 5m from the CU in a straight line and ignoring corners.
There's at least 15 other houses the same on the estate but the NIC couldn't care less about checking those too. It's a sorry state of affairs when one of the biggest companies responsible for ensuring competency don't care about the regs
@@mattbeddw i completely agree with you but that regulation is not in bs7671
See loads over 3m no interest in complying just do the easiest option and then tick the box
@@mattbeddw In my experience NIC just concerned with taking money from firms,no interest in resolving issues. Got to be time to make building regs and our regs the same.
The Wilex DSF80 & DSF80M are great. “M” at the end for metal is like bigger one here, and the non metal one is like a much better version of the little one but is much harder to source stock of. Ps. 80 in the model number for 80A, but they also do 60A, 100A and unfused versions.
Yeah those Wylex are great 👍🏻
excellent content. Thanks !
Great video. With relation to a hrc fuse in isolator for consumer tails >2-3 meters for fault protection will the dno fuse not operate in any case if there is a fault as the pre arcing on the isolator fuse is not likely to be less than the let through energy of the dno fuse
This was brilliantly timed as you turned the switch on some little girl started screaming outside my house lol
😂😂😂
With regards to the having armoured incomer in the bottom (25mm) are you saying you would double browns up? Or change the wiring on the fuse holder around? Thanks
Your information is good
I used to fit the meters on new builds and used all of these as well as the standard Wyler double pole isolator. My only tip would be if the sparks on site are fitting their own isolator so they can run SWA which is becoming more common, let the meter guy know or fit it prior to him/her coming and they can fit tails straight into it. This avoids the scenario of having to squeeze 2 double pole isolators in the box which ends up happening frequently
Wise words 👍🏻
Worth noting that the meter operators won't connect to a device whose enclosure is not made from non combustible material, so got to be the metal domestic switch fuse if you want to omit the 2 pole isolator.
@@Daniells1982 interesting, even though the double pole isolators and the meters themselves aren't made from non-combustible materials?
@@mattbeddw yeah I know mate, it's because there is a protective device in the assembly, not just a switch. There must be a document kicking about which stipulates this with BS EN numbers no doubt.
@@Daniells1982
What if the meter cupboard has a metal door? Can the isolator be plastic?
.
The smaller switch fuse I have used before and I do like the one in the enclosure, BUT Lewden could have made the enclosure just a bit taller so you don't have to fight the cable in to it
According to OSG B5, 100A 1361-2 cut out fuse will operate when Zs low than 0.26 ohms( Cold meter tails measured @ 10 census and hot cut out upstream? not sure, why use correct factor, just small length meter tail cold) , would you mind explain why DNO still keep 0.35 ohms limitation on TN-C-S. does this arrangement will make 100A cut out 1361-2 fuse operate when earth fault even short circuit?
One of my first jobs in the early 1990s after getting my diploma was rewiring a couple of flats, with the "at a distance from meter" problem. Nothing like it was covered in my course, so I went back to first principles and worked out everything from scratch. Overcurrent/Isolator must be within 3m of meter, downstream then sized to route to the CU in the flats. "I want that unsightly cable plastered in" No, because then it's not protected, and will have to be armoured and cost XXX hundreds extra!
How are you satisfying IP4X on the top entry of the smaller switch fuse?
Are you just saying it’s in the meter cupboard? Therefore in a lockable cover?
Looked at these for the first time recently for a board change job where there are currently 16mm tails running diagonally in the cavity for a few metres; I know running cables in the cavity isn't specifically banned but I'm not totally comfortable with it; if there's no conduit- not sure what the cavity insulation was like in the 70's though. Am I being unnecessarily cautious?
Having a 25mm^2 earth terminal differentiates these economically priced units from the Wylex equivalent; fitting a 25mm SWA feels like appropriate future proofing if the size of bends can be accommodated but most boards only accept a 16mm main earth; I'm still wondering if there's a screwed alternative to pin crimps as my existing crimp tools max out at 16mm...
Terminate swa into a metal box then into fuseboard...put the 25mm earth into a henley block the break out as required..and mark as "earth connection dont disconnect"
What about existing 16mm twin & earth in a property that has been installed through different floors? Is there a device that has RCD protection as well as a fuse?
Were dose it apply from being 50mm or more for RCD as if the switch is on the surface so are the tails going in to the wall so from what point dose it come in as the tails don't go out the back of the switch.
I used this on a house with 3 flats inside where the new incoming UKPN 3-phase cutout was installed on the outside of the building and the meters were in the basement. When the metering company came to re-connect their meters they objected to their being an isolator before the meter. The said there can't be anything between the cutout and the meter. They also objected to connecting armoured cable in to their meter. Thoughts?
I wish you'd show how you wired the MSF isolator with 25mm tails ! You barely get one thread on the screw to hold down tails.
Hi do you use the same size fuse as what the DNO has supplied in the head or down grade the supply to the next size fuse rating for discriminating purposes??
I'm DNO doing RLM installs ( sometimes ) and we often fit the same size fuse. It's 50/50 which one goes first but with low carbon technology jobs we must ensure customer has an 80 amp fuse. With these KMFs it means we would have to go to 100 amp in the cutout but often we can't. As you know, a 100 amp fuse can easily carry 120 to 130 amps for many hours which is beyond the rated current of the cutouts we use and puts undue stress on the network should that current be pulled.
If the customer has a 16mm² T&E submain we allow 80 amp but put the onus on the customer to get an electrician out to upgrade it. If it looks like they won't, then it's a 60 amp only.
Noting both your things included fuses, are fuses necessary there ?
seeing how that 2nd box came with 3 amperage of fuses, it makes me wonder if i could get my utility to upgrade my supply fuse (the one with the seal) to a bigger size? The property was built in the early 60s with a 4-way consumer unit (Cooker, ring, immersion, lights). i'll be looking into an upgrade to the CU in the near future (along with earth bonding)
Isn’t the No 2 slotted already in the driver?
Can you mount these side ways if existing armoured already in place and no slack to mount metal box in the vertical plane?
Woah! the small main switch one, we used to have that in Malaysia like 2 decades ago lol.. now everyone's replacing it.
Plastic consumer units/ switch fuses do not comply with domestic installations even if they are mounted on the exterior wall of a house?
Good video
Re torque settings. It seems pretty intuitive to me that for best results the torque used should not only be dependant on the terminal design (fixed), but also on the structure of the cable (variable) i.e old style 7 strand tails compared to the Flexi tails. Has any of the electrical RUclips channels experimented with the effectiveness of different torque settings vs different cables? I for one would certainly be interested to see the results.
See page 11 of this document - www.electricalsafetyfirst.org.uk/media/1258/consumer-unit-connections.pdf
My old man was working at a farm cottage where the tails went 15M from the meter box to the c/u. Can this type of fused isolator be used or should it be rewired with swa or something before using the fused isolator?
Thanks
If you run armoured cable, on an outside wall, would that need an RCD?
do you have to run separate earth to the consumer unit if using armored cable or can you use a 3-core armored cable and use one of the cores as the earth?
You can use armour to carry earth, so long as it can carry enough fault current. But I keep seeing in videos like this, where they use 3 core, and don't know why.
I've seen loads of the smaller fused isolators with that additional cover and armoured cable used, the meter engineers can fit the tails direct to them.
I can send pictures.
I would be interested in seeing that
@@alanbeard4871 I can't send pictures on here but send your email and I'll send some over in a few days when I'm back from holiday.
I’m about to move a consumer unit on a refurb 11 meters with split con.
The property is on a TT supply so will be fitting the Fusebox version with a 100a 100mA time delayed rcd and an 80a fuse (new head has a 100a fuse fitted by dno). Fortunately the service head is inside the property so no need to worry about space.
That's the way I would do the job .
I fitted an extra meter box so the fused isolator wouldn't be in DNO meter box, perhaps I went over the top? On the other hand at least there's plenty of space now for a henly block and second isolator for an EV charge point.
IM Bangladeshi..... Nice 🥰
At UKPN regarding meters to be moved on service alts they are now slowly rolling a process of the jointer to move a meter then connect incoming meter tails from cut out to incoming side of the meter and then away going tails to a double pole isolater switch. And the electrician will then be down to them to make the final connection there side to the away going side of the double pole isolater switch. To me it’s a great solution one you don’t need to have a bs7671 test cert from the sparks as all the jointer is doing is connecting up to a double pole isolater and that’s it. So you can walk away and leave electrician to make final connection on away going side of the double pole. Plus it’s a point of isolation for a sparkey which means the main fuse does not have to be touched which we all know electrician’s aren’t allowed to do.
Looks like the s2 is in the screwdriver handle?
Try watching it again ... they clearly say ''slotted pozi No.2''! I've little doubt Gary has it stashed somewhere to probably deter these two from borrowing his little pouch. 😉😉😉
I have the 2nd solution and it’s where it shouldn’t be ;) but no where else for it to go as it’s straight out to my armoured cable going my garage
With regards to the Msf from lewden (plastic kmf switch fuse) how does this meet the requirements of 421.1.201? Surely we should be using non combustible (ie. metal) switchgear assemblies within domestic premises?
Asking for a friend🤣👍
They had been around long before the metal mandate. They are not a CU, so I guess don’t need to be metal
Is an external meter box inside the premises ?
Reckon these blokes could do a days Graft or just pen pushers and book readers ?
We're pen pushers, book readers AND proper grafters matey. Get you a fella who can do it all! 😂
How do the “grafters” now what to do if the pen pushers and book worms don’t lay down the theory?
@@abdulseaforth6930 common sense you either have it or you don’t, seems like you’ll be forever searching for it
what are the rules for switched fused isolators between the cut out and meter?
My cut out is a solid link can this be used as additional protection
yes should offer 30000 amps of additional protection
Here is a question, If you have 25mm 3 core SWA providing a supply to a consumer unit... Will the 25mm cpc fit into the earth bar in a consumer unit? I often have to wrestle a 16mm cable... Whats the best solution for this? (Obviously line and neutral go into main switch which is fine)
Why not just use two adjacent ways, if the earth bar doesn't accept 25mm?
@@obd6HsN split the conductor strands, yeah thats a simple and really good idea.. cheers.
I had an electrician try to fit the larger unit into our meter cupboard yesterday but there wasn't enough space. He's gone to source another solution. Its for a 16mm SWA that runs to my garage.
4:08 - if this is mounted inside the meter cabinet, then would the "cable duct" still be required to attach to twin & earth? Obviously this would look rough, but from a regs point of view it should be OK, shouldn't it?
Well surely yes, because you can’t have basic insulation showing
@@ElliottHurst even in an enclosure that requires a tool (key) to open?
I wouldn't want to describe a box owned by the homeowner and containing a meter which they may need to read from time to time an enclosure suitible to have single insulated cables in, backed up by the fact that dnos and energy suppliers use double insulated tails to connect their equipment in the meter cabinet.
If the incoming supply is fused at 100A do the regs allow you to put another 100A inline?
You would have no discrimination if you fitted a second 100 amp fuse . It would have to be a smaller fuse .
@@dennisphoenix1 Yes, as most households in the UK are 60, 80 or 100 amp, this Lewden fuse switch would have difficulty providing discrimination. Even if you could get it, it would limit your options further down the line.
@@dennisphoenix1 erm... ‘selectivity’ lol
The 3m tails thing doesn’t exist with lots of energy suppliers and DNO. I know that since the Grenfel Tower incident in London, Western Power Distribution no longer get involved with tail lengths and hand that responsibility to the energy supplier. I’ve had a recent job whereby the tails length was 7m and the energy supplier was okay with that.
We’d make sure you get that in writing - energy suppliers change - DNOs don’t !
What is the RCD solution if you come across tails buried in a wall and longer than 3m??
It would be better to have what the French have, a 500ma RCBO with integral double-pole isolator instead of a main fuse. Both L & N are then disconnected when isolated or a fault trips the device. In France the maximum amps of the RCBO is settable.
But the DNO has an old hat main fuse so we are stuck with yesterday's technology. You can fit your own main DP RCBO disconnector in one of these boxes being far superior.
They are available for £50 as RCBOs with a fixed max' amp current. All is needed is a two module box with a DIN rail. Protection is then far superior to this large 1950s set up of switch and single pole disconnecting fuse. About time we caught up with the world.
OK, we‘ve been using these for quite a while (D02 fuse in Europe), but usually in an commercial environment.
The unit is actually fully isolated when the cover is open, so no danger when changing the fuse.
But please try to pronounce the German name for this device:
„Sicherungslasttrennschalter“ 😀
Bending radius of that tri rated 100A
Internally?
Regardless of tail length, surely it's long past time that a whole house / installation isolation switches were made mandatory?
How many times have you heard a sparks say I'm not supposed to but I'm going to have to pull the main fuse… ?
👍
I thought all sparks had a 'Pablo' who comes out to pull the main fuse? :D
@@mikehealy74 That Pablo doesn't half get about, I used him just this week
whats the 3 phase solution?
Where the hell are you going to get armoured plate? I'm pretty sure they don't sell that in the wholesalers
Use the Lewden large switch fuse which is a good priced and well made. Shouldnt the small one be made from non combustible material? As its got a fuse in it. Ive fitted them in the mains cupboard on many occasions as i usually have split con with exposed inner cores in the meter cupboards
guess it's fine for outdoor meter cabinets
@@edc1569 but fuseboards in external buildings have to be metal! Dont get it!
In the not too distant future, I'll be running some tails on the surface, through a wall and it'll be fixed to the wall with cable ties n tie bases.
The supply will be coming straight out of the head, into an fused isolator, through a wall and up a meter or so to a fuse board as I'll be putting in a new supply.
The question is.....The fused isolator would be deemed "switchgear" and the ENA do not permit switchgear within the meter cabinet. A standard double-pole isolator does not have a fuse and therefore is allowed within the cabinet. Can the EFIXX presenters clarify on this please?
The official line from the ENA is they do not “recommend” installing switch gear inside the meter cabinet. Individual DNOs may take a different approach.
I'm not sure a fuse is switchgear. Breakers are switchgear and they need to manage the way an arc is drawn as they operate to interrupt a fault current.
Cartridge fuses on the other hand are self contained sealed units that not only contain the arc in a known environment but gurentee that there's nothing flammable around it - even if everything else has 40 years of dust.
If these were switchgear then the plastic one would be banned from domestic by virtue of 421.1.201.
@@efixx But if we install the same rating fuse in our new fused isolator, how can we achieve full selectivity with the DNO fuse? If the is a fault on the consumer meter tails, it is likely that the service fuse will fail before the fuse in the fused isolator
So is it 3m or 2m? it must be important otherwise it wouldn't be important,is it a recommendation or a legal requirement?
25mm2 twin and earth cable, any every used it?
didn't think it even existed
If you run tails up a wall, should they be covered over? I had a sparkie upgrade my tails and the patch plaster barely covered them. Just the cable he chased into the surfaced plaster that was onto breeze block. It's on a rental that he did me a certificate for after. I thought it was a bit dodgy but he said it was fine
They'd need to have RCD protection if they're buried that shallow. 🤔
Even that's not a perfect solution as you can run into issues with selectivity.
@6:00 you mention "this other solution.... consumer unit containing a switched fuse..." over the 'solution of swa'.
If I am understanding correctly what was said then the implications is that the swa isn't needed if you have the switched fuse... and your own 'tails' from the switched fuse can be buried less than 50mm deep without any armoured/earthed protection to your consumer unit located Xm away.
Apologies if I am misunderstanding what was said... just slightly confusing as the 'other solution' was shown with SWA but the voice over seemed to suggest it was two different approaches.
Confusing video so can you run tails to a longer length if a KMF IS USED
You can run longer tails if you aren’t relying on the distributors fuse to protect them.
1:53 how does this pass the eddy currents argument?
It’s a plastic enclosure
@@efixx fire rated?
Why supply the 100A fuse you have to use a smaller fuse than in the service head..... ie 100A in service head and the maximum you can fit is 80A
In regards to the first switch fuse shouldn’t it be made of metal as it contains a fuse and main switch.
Also only one screw clamping the 25mm tails. Very poor. Asking for a fire
Not switchgear - doesn't contain a circuit breaker. In terms of one terminal holding the tail, yeah its not a good look. But it's exactly the same for most meters - and they don't come loose mainly because they are done by competent people.
You have installed main switch cover upside-down ;) Thats why you needed to "power on" to take it off.
they should make swa tail
3:50 - 25mm T&E??? Wouldn't it be better to just run some 25mm SWA to the CU (It is protected then!)?
The largest t and e is 16mm2
Sorry, I should have watched ahead first! lol
Obviously sponsored by Lewden - but can you switch it on once the cover is removed ??
Plastic version no (as it has exposed terminals)- metal version yes - terminals are IP20z
Why are meter tails twice the diameter compared to the feed from the pole? Especially as that feed can be much longer than 3 meters. I don't get the physics.
Air cooled
I see this reg being broken all the time, just moved in to a new build where they have run 15m of tails through the building and covered them in some sections with unearthed 2x2 metal trunking all signed off by the Nic EIC contractor, just the usual focus on got the paperwork so the jobs been done ok 😂, unfortunately the trade has become to focused on paper work from the roots of college and apprenticeships to onsite, where the importance should be on doing the job properly and having pride in doing so, with regards to the 50mm depth never got the logic of that fairly sure masonry bits and screws are longer than that😂,SWA should be the industry standard would maintain safety to all installations.
Can the first isolator have the cables reversed? Technically there is no reason why that cannot be the case.
If you reversed the connections the fuse carrier would be live when the switch is off . So no you can't reverse them .
Or instead of doing it right you can copy the big house builders and gland the swa into a right angle bracket with basic insulation exposed and terminate in meter providers isolator
If you brought the tails in from the top, them wouldn't the double pole isolator diagram be wrong? The switch would be upside down surely
... so how do you connect the live side tails safely without removing the DNO fuse...?
Take the fuse out, don’t be a girl
...Electricians are not currently permitted to remove the DNO fuse
I think the point is if you are installing on a new build before the power is connected.
@@mufc2090 if you had been on a approved course for removing DNO fuses in street lighting columns you would have seen the pictures of when it's gone wrong and the injuries and destruction caused . If the cutout breaks when you are pulling a fuse you can short out phase and neutral /earth and have 2ka flowing in front of your face . Not to be trivialised .
Where is the SWA hood though
PSST, pick up and ask the screwdriver where No2 is . 😎
hidden in sight 😂😂😂
If we were to run tails in the joists lets say 15 meters to another location , could we replace that main switch for a 100mA Rcd time delayed
Would this be acceptable ?
Any reason you can't use a 100A time delayed RCBO as a main switch?
None if it is DP. The problem is that if there is a problem the whole house installation is taken out.
I like the time delay solution myself, but is it adequately protecting tails?
The flat bit is in the handle
❤❤👍👍👍👍
My smart meter installer put a switch in. No fuse.
I only use the plastic one if the metal one won’t fit in space.
Am I missing something? The MEM 80A fused main switch similar to this does not allow the fuse carrier to be removed without taking off the front cover exposing all the live parts- what's the point of that? What a silly design...
why do they all have fuses. we all know MCB are better which is why we use them on the boards. so why use fuses in an isolator?
I don't understand the logic of fitting the same size rated fuse as that in the cut off, there is no added protection against overheating.
Personally if I have to run over three metres of tails my personal best solution is no certification and cash in hand only 🤣🤣
Why is an isolator with a *fuse* needed when the DNO provides a fuse inches away? Why not just an isolator only?
Also, if the DNOs fuse is 80A, should next size down be fitted, say 63A, as it will not be certain which fuse will blow if they are rated the same? 😳
Think about Zs, The more length meter tails the more Zs.
This is only applicable to overcurrent protection , on a short circuit fault either can blow
@@persona250 over current protection means overload & fault current( earth fault or short circuit). Try to find or calculate how much current will blow the 100A 80A 60A 1361 fuse, and test the Zs@DB or Pefc Pscc, you will know how low Zs should be keep and decide whether you need install additional fuse to protect the meter tail cable connect your consumer unit. If the Zs is higher not blowing cut out fuse, you should install additional fuse. And location should be installed before Consumer Unit.
25mm tails 10 meters ( SWA 3 core) length will increase 0.014 ohms resistance. Say 14 meters will increase to 0.2 ohms. If we increase meter tails from 3 meters limitation to 17 meters. The Ze will near 0.37 ohms (TNCS) , above 0.26 the 100A , above 0.38 for 80A, above 0.53 for 60A 1361/2 fuse don’t operate. Some don’t use 25mm for earthing conductor. If they use 16mm for earth, 10.1meters more will increase 0.2 ohms.
Very common measured 0.20-0.25 for TNCS. If cut out use 100A fuse, who know someday the Zs could be near just say below 0.35 and DNO could say it is ok. But actually it won’t blow the fuse even in short circuit fault.
For TN-S, 0.8 ohms Ze limitation could not below fuse in earth fault, maybe blow fuse in short circuit fault , so ideally install time delay RCCB before CU and careful check Pscc. For TN-C-S meter tails no more than 10 meters could be no issue.
@@huyongquan6554 no my man they are different . an overcurrent of 125 amps will blow the 80 amp fuse but not the 100 . A short circuit can be in the 1000 amp range which will blow either fuse first .
Suppliers don't want meter fitters connecting their meter equipment to that! We'd have to install our own isolator. The industry has gone mad.
Not sure which suppliers you’ve had on site, but I was briefed some years ago now on being able to install to these providing the tails are “pre-connected” doesn’t always happen but it never stopped me installing to them
@@minitom7772 Ovo, UW, NPower, EON, EDF, Octopus. I'm also told this is a MACOPA thing! We are not to energise a new build, hence we can't (shouldn't) connect the meter to the existing (customers) isolator (often a fused wilex almost as big as the whole OMB). It's a waste of time and equipment. This industry often lacks common sense. Surelly making use of the existing customer isolator and leaving it in the off possition with a safe notice should suffice.
@@CarlosArruda77 I was fitting for BG provided the metal isolator had been pre-wired, we connected the outgoing meter tails to it, the requirement being however the fuse must be removed and left with the site manager. Never heard or saw anything saying otherwise from MOCOPA
@@minitom7772 I've been in the industry for 6 years and I'm yet to come accross a supplier that will allow that. But, makes perfect sense mate.
@@CarlosArruda77 10 years here mate, that’s the daft thing with all these suppliers, they all have their own hymn sheets. Bloody ridiculous