This used to drive me nuts in my old house. Such a simple explanation but all the same I'd have never figured it out in a zillion years. I am demystified at last. Thank you so much for this!!!
Thanks for the videos John, I find them very informative, easy to understand and a great back up for my level 3 2365 . Thumbs up on every video so far. Thanks.
great video, explains what i was after. this happened to a street light while i was working on eastenders. the lamp wasnt working, it was disconnected from the supply but there was about 50v between earth and neutral. i have been trying to figure out the cause since. thats scratched an itch! cheers john, all the best.
Extremely helpful video as usual from John. I watched it so carefully that I noticed that you edited the video at 4:27 :) Thank you very much. You saved my day! Your video confirmed my suspicion of a N-E fault in a residential installation in which the responsible 30mA RCB was switching off every 5 minutes! despite all the MCBs switched off (and Live bus bar removed, just in case). Locating or narrowing down the fault is as easy as removing the Neutral wires one by one from the Neutral bar and see which one trips the RCD.
Brilliant explanation - thanks John! As well as understanding why neutral/earth shorts trip the RCD I also finally understand why the RCD has no interest in the state of the earth!
Thank you for explaining this so clearly. The scenario you mentioned in the first 40 seconds was exactly what happened to me today! I knew what I did - but didn't understand why this happened. Now I do - 9 years after you made the video!
Excellent explanation, John. I see this sort of things with inspecting caravans, where the owner has wired the damn thing themselves and left the link in between the Neutral and Earth busbars at the little switchboard, that's normally in the smallest cupboard ever. It's that time of the year at the moment, considering people can't fly out of New Zealand because of Covid-19 restrictions.
You have answered a question from years ago when I replaced a socket in my house. I tripped the RCD even though the circuit I was working on was isolated and I suspect I did exactly this. Thank you
Hi John EVER So many thanks for this informative video. Now I know when cutting through a cable with the appropriate line mcb OFF, the rcd trips. Thank you again. For this brilliant video.. Please keep up the good work.
Hi John, yet another very helpful video - you have a great talent for education. Thanks very much for all the time and effort you put into this Channel, cheers.
You know, we're redesigning our Hackerspace's electric circuits, and your videos are very big help. :) We're situated in the buildings decommissioned bunker and thus we have only one single 10A fuse for our space and it's pretty much inadequate for our needs. All the sockets and lightning is behind that one fuse, so we're going to replace the main cable with bigger one, install bigger fuse to the other end and a consumer unit for our space so if we trip something, we don't have to walk all the way to the buildings main fuse box (that's behind locked door) to get everything up and running again. The idea is, that we design and build all the new connections etc, without making them live and then sparky with proper equipment and credentials comes up, measures and checks everything and connects it up to the mains so it's legal. But since it's been like 13 years when I went trough the courses about electric installations, it's been a good resource to remind myself about the topic. :) Luckily we have a memeber with automation as his credentials, so he's a big help even if he doesn't have the classifications of a sparky. All we need to do is to make sure, that the differences in standards between Finland an UK aren't going to be too large so our sparky doesn't get a face palm when he sees our designs. :D So thanks a lot :)
This has helped massively to understand a fault that developed after getting some walls plastered. Trying to work out the fault using the MCBs alone was fruitless as the RCD would randomly trip. knowing the RCDs are double pole and mcbs are single leads me to believe something is still wet causing an NE trip. Problem is trying to work out what is wet.. Nice clear video tho!
Great informative video. Interesting to see that the cooker goes through the RCD. In NZ the cooker and hotwater cylinder don't go throught the RCD as heating elements sometimes have leakage and cause nuisance tripping of the RCD.
RODALCO2007 Virtually everything has RCDs now, as regulations require it for cables concealed in walls. The other options being to use armoured cables, steel conduit or having concealed cables more than 50mm below the surface - all of which are far more inconvenient and expensive than fitting an RCD. Cookers and similar are a problem, such as where a new consumer unit is fitted and the cooker which worked perfectly before now trips the RCD on a regular basis. Have also seen the same problem with people buying a new cooker, where it's been stored in a damp environment before delivery.
***** Thanks for your reply. In New Zealand a hotwater cylinder and range/cookers don't have to be on a RCD because of the leakage issues encountered sometimes with enclosed elements. Values are often around 10-15 kO.hms. and the element has still plenty of life left in them. The NZ standard also requires 2 RCD's at least to avoid loosing all power in the house.
greetings, I'm well late to the party here, but nonetheless I thought you would be interested to know The AS/NZ 3000 wiring rules are just about to have a new edition released, with one of the big changes being RCD everything. Every circuit needs its own individual RCD, including water heaters, ovens and cookers. One other big change is that if anyone who is working at a domestic residence needs to do work in the roof, they need to shut the power off to the whole installation which is interesting. you can follow this link for a preview of the planned revisions. www.commerce.wa.gov.au/energysafety/new-wiring-rules
We still use GFCIs at the receptacle here in the States, even though GFCI breakers are perfectly acceptable and code compliant. The big thing now here are AFCI's (Arc fault breakers). They are required at the breaker panel on almost every circuit in residential installations these days. (They've been required since 1999 in bedrooms, but now are required everywhere). I hear they aren't a requirement yet in the UK, I presume because you guys protect all cables with metallic sheathing. In any case, studies have shown that around 50% of electrical related home fires in the U.S. are a result of arc faults (series more than parralel) hence the new requirement. Here most homes use non-metallic plastic sheathing rated at 90C. While it's safe cable, it's still non-metallic sheathed meaning it is feasible that it can be damaged in the wall (errant nails or rodent chewing), thus the potential for unseen arcs which normal breakers won't detect. Some metro areas require metal sheathing for residential applications. Chicago is one city with very strict standards in that regard. (Here states and local munincipalities have the authority to override the national code with their own code). It makes sense in those areas because if one condo or apartment building burns, the whole block burns. It doesn't make as much sense in the country where your nearest neighbor is a mile away. We also have many very old homes here. It is not uncommon to see old homes with "knob and tube" wiring from the 20's. It is legal, but if renovation is done it must be brought up to code. And we have tons of homes from the 50's to 70's using wiring code from back then. Grounding has been code since the early 60's I believe, but there's still many homes out there without an earth ground circuit (all receptacles are two prong). Some unscrupulous people will install 3 prong receptacles in an old home without a ground circuit, thereby creating a "bootleg" ground. This is achieved by connecting the neutral to the metal electrical box. This will trick the inexpensive receptacle testers into reporting there is a proper ground. These cheap testers are used by most home inspectors, and creates a dangerous situation for an unknowing home buyer.
Thanks so much , my broken underfloor heating caused me issues and was tripping the other RCD circuit confusingly, Just disconnected from the thermostat and all good now.
Cheers. Excellent explanation. This had me puzzled while doing some electrical work up in my gran's attic, I thought she was flipping the main breaker as she's terrified of electricity. I'm cautious; test with a NCV tester then a multimeter before work especially as whoever did the wiring in that attic had no idea what they were doing, flourescent strip light in *series* with a ceiling rose (not for lack of wire, they just left the live wire flapping in the breeze),steel cored speaker wire (or something similar) hooked up to live and neutral leading to seemingly nothing, if I had to hazard a guess it was for an old doorbell and just reconnected by every contractor who did some work there, though why it is on the attic lighting circuit is beyond me. All of these things had me fairly worried about the house being plunged into darkness as I was concerned that there was a live (or intermittently live) conductor somewhere. Turns out it was neutral touching earth, which I'm sure of as I tested it twice. Measured with a multimeter and got .7 volts, guess the current was enough to trip the breaker though.
I've had this happen when I made up an adapter for a caravan to run on a regular 10amp NZ socket (for the lighting and light loads). The caravan fuse box had a linked neutral and earth bar and would trip the RCD when plugged in. I had to remove (cut) the earth neutral link while still keeping the earth neutral wires connected to the plug on the caravan
Hello, Excellent video, as usual. Could you please do a video on RCBOs, and particularly on why they have the separate white earth leads. I am a trainee electrician, and was told by one qualified electrician that they are to prevent nuisance tripping, but another qualified electrician didn't know what they were for
The white lead is an earth connection and it is usually used by the TEST function of the RCBO... which creates a deliberate imbalance to earth in order to cause the RCD part to trip. If you don't connect it, the TEST function usually doesnt work. Some RCBO's are designed so that they don't require that earth connection
Great videos John. Currently got this problem and after disconnecting and replacing all neutrals got the problem down to sockets in lounge but cannot locate where problem is by removing each socket as all wiring looks ok. Is there a possibility that it could be a faulty MCB.I am in UK. Thanks
When making alterations to a circuit covered by a shared RCD (i.e. split load board), I will now disconnect the L, N & E of that circuit to prevent nuisance tripping as well as being a means of isolation. It will need to be done for dead testing anyway!
Great video ! I just saw it and I think one solution for this is to use 2poles or 1p+n MCB s instead of 1 pole. So when you disconnect the MCB both line and neutral are off . The regulations in my country recommends to use that kind of MCB s. Of course RCBO s on all circuits is the best solution but it is more expensive.
In NL we use one RCD for every 4 MCB's. And indeed 2p RCD's. They recommend RCBO's for outdoor units like airconditioners, outside lighting and solar panels.
I faced this issue last month and was surprised that even though Sockets MCB is turned off , why does RCD trip whenever Neutral touched Metal/Earth...Thank you very much for your videos
Been there and done that - I was rewiring a socket and I twisted the bare ends of the cable together and the RCD tripped as explained plunging the building into darkness. The situation was only saved as I had a head torch in my pocket that I was able to find in the dark. Moral carry a torch at night particually when working on electric circuits.
Is there any way to simply determine if it's a 'neutral to earth' / 'live to earth' / 'live to neutral' fault that trips the downstairs light breaker? Cheers for advice.
Mr.John please help understand me. With regards to rccb that is too sensitive when lightning occurs. whether grounding is not good enough or there is another reason.
if i am replacing a light fitting on an individual circuit containing several lights ( and ive isolated it and made it safe) and i know its going to trip the rcd to other circuits which will bring a shop to a grinding halt, which conductor would i reconnect first to prevent it tripping and then in which order after that (to reconnect the other two). also could you explain why they are reconnected in that order. thanks John, i hope the question makes sense
@John Ward I stand corrected. I agree there should be a common neutral bar for the neutral connection of all loads controlled by this RCD. But I believe this neutral bar should be unique to this RCD and should not be connected to the neutral bar where the incoming neutral and non-RCD loads are connected. Please confirm.
What you're saying is that double pole mcbs are the way to go (especially since they exist in slim form factors), so that I can also isolate neutrals. The system of only disconnecting the line is a pain in fault-finding
JW Ive been wanting to get a Fluke 1653B - to test systems here in the US... But now we have ARC fault breakers - will this damage the meter in anyway? I was wanting to do a trip test and get a time/ amp reading on each 120vt circuit here in the US , any advise ?
Here I am again watching this video 2 years later. You are a national treasure JW.
This guy is great. So informative and explains things clearly
Thank you. I have always wondered why an RCD can still trip even if you have the power off on the circuit you are working on, now I know.
This used to drive me nuts in my old house. Such a simple explanation but all the same I'd have never figured it out in a zillion years. I am demystified at last. Thank you so much for this!!!
you have a knack of explaining stuff that even I can understand
Thanks for the videos John, I find them very informative, easy to understand and a great back up for my level 3 2365 . Thumbs up on every video so far.
Thanks.
great video, explains what i was after. this happened to a street light while i was working on eastenders. the lamp wasnt working, it was disconnected from the supply but there was about 50v between earth and neutral. i have been trying to figure out the cause since. thats scratched an itch! cheers john, all the best.
This guy is quality... Makes everything make perfect sense... Thanks alot John
Hi John... Many thanks for your time too explain in depth the earth / neutral faults.
Extremely helpful video as usual from John. I watched it so carefully that I noticed that you edited the video at 4:27 :) Thank you very much. You saved my day! Your video confirmed my suspicion of a N-E fault in a residential installation in which the responsible 30mA RCB was switching off every 5 minutes! despite all the MCBs switched off (and Live bus bar removed, just in case). Locating or narrowing down the fault is as easy as removing the Neutral wires one by one from the Neutral bar and see which one trips the RCD.
Thank You John Word for all your lectures. you have used a simple and clear way to be understand
Thanks for doing this John - very well explained.👍
Absolutely brilliantly explained for a layperson to understand the basic concepts! Well done!
great teach ! it help me self repair the damage breaker ! thanks John Ward !
Brilliant explanation - thanks John! As well as understanding why neutral/earth shorts trip the RCD I also finally understand why the RCD has no interest in the state of the earth!
Thank you for explaining this so clearly. The scenario you mentioned in the first 40 seconds was exactly what happened to me today!
I knew what I did - but didn't understand why this happened. Now I do - 9 years after you made the video!
No one would fail their Electrical exams if you were the tutor. Great stuff. From a non electrical person!
This is one of the best explanatuons with demonstrations I've seen. Well articulated.
Well this explains exactly what happened to me the other day! Great timing with the video. Thanks
Great .. amazing video , this can be overlooked when working in the field. Thanks for uploading.
Excellent explanation, John.
I see this sort of things with inspecting caravans, where the owner has wired the damn thing themselves and left the link in between the
Neutral and Earth busbars at the little switchboard, that's normally in the smallest cupboard ever.
It's that time of the year at the moment, considering people can't fly out of New Zealand because of Covid-19 restrictions.
excellent simple explaination straight to the point. thank you
You have answered a question from years ago when I replaced a socket in my house. I tripped the RCD even though the circuit I was working on was isolated and I suspect I did exactly this. Thank you
I just love the occasional dry humour, makes for interesting listening.
many thanks for the detailed explanation.
This exact thing happened me tonight. I thought it was something to do the balance, but you explained it perfectly. Thanks.
clarity on a consign issue I have..Thank you so much
Thank you so much for your videos it makes so much sense. Really interesting to understand how it all works.
Hi John
EVER So many thanks for this informative video. Now I know when cutting through a cable with the appropriate line mcb OFF, the rcd trips.
Thank you again. For this brilliant video..
Please keep up the good work.
Excellent video and very well explained! Thank you!
Very informative. Thank you!!
Hi John, yet another very helpful video - you have a great talent for education. Thanks very much for all the time and effort you put into this Channel, cheers.
best explanation ever. as simple as that! thank you!
Great stuff John, thanks!
Thank you very much, that helped me to fix my fault last evening
thanks John for explaining this.
Lovely explanation. Many thanks!
cool videos John.. Very helpful information
Excellent explanation ! Thank you
You know, we're redesigning our Hackerspace's electric circuits, and your videos are very big help. :)
We're situated in the buildings decommissioned bunker and thus we have only one single 10A fuse for our space and it's pretty much inadequate for our needs. All the sockets and lightning is behind that one fuse, so we're going to replace the main cable with bigger one, install bigger fuse to the other end and a consumer unit for our space so if we trip something, we don't have to walk all the way to the buildings main fuse box (that's behind locked door) to get everything up and running again.
The idea is, that we design and build all the new connections etc, without making them live and then sparky with proper equipment and credentials comes up, measures and checks everything and connects it up to the mains so it's legal.
But since it's been like 13 years when I went trough the courses about electric installations, it's been a good resource to remind myself about the topic. :)
Luckily we have a memeber with automation as his credentials, so he's a big help even if he doesn't have the classifications of a sparky.
All we need to do is to make sure, that the differences in standards between Finland an UK aren't going to be too large so our sparky doesn't get a face palm when he sees our designs. :D
So thanks a lot :)
Thanks John. Exactly what I am experiencing with my oven at the moment.
Excellent and informative videos thank you
Very good video as usual John
Delivered really well. thanks alot mate.
Excellent explanation!
Very nicely explained.
Thanks John 👍
thanks for the vid - really helpful!
This has helped massively to understand a fault that developed after getting some walls plastered.
Trying to work out the fault using the MCBs alone was fruitless as the RCD would randomly trip. knowing the RCDs are double pole and mcbs are single leads me to believe something is still wet causing an NE trip. Problem is trying to work out what is wet..
Nice clear video tho!
Great informative video. Interesting to see that the cooker goes through the RCD. In NZ the cooker and hotwater cylinder don't go throught the RCD as heating elements sometimes have leakage and cause nuisance tripping of the RCD.
RODALCO2007 Virtually everything has RCDs now, as regulations require it for cables concealed in walls. The other options being to use armoured cables, steel conduit or having concealed cables more than 50mm below the surface - all of which are far more inconvenient and expensive than fitting an RCD.
Cookers and similar are a problem, such as where a new consumer unit is fitted and the cooker which worked perfectly before now trips the RCD on a regular basis. Have also seen the same problem with people buying a new cooker, where it's been stored in a damp environment before delivery.
***** Thanks for your reply. In New Zealand a hotwater cylinder and range/cookers don't have to be on a RCD because of the leakage issues encountered sometimes with enclosed elements. Values are often around 10-15 kO.hms. and the element has still plenty of life left in them. The NZ standard also requires 2 RCD's at least to avoid loosing all power in the house.
greetings, I'm well late to the party here, but nonetheless I thought you would be interested to know The AS/NZ 3000 wiring rules are just about to have a new edition released, with one of the big changes being RCD everything. Every circuit needs its own individual RCD, including water heaters, ovens and cookers.
One other big change is that if anyone who is working at a domestic residence needs to do work in the roof, they need to shut the power off to the whole installation which is interesting.
you can follow this link for a preview of the planned revisions. www.commerce.wa.gov.au/energysafety/new-wiring-rules
We still use GFCIs at the receptacle here in the States, even though GFCI breakers are perfectly acceptable and code compliant. The big thing now here are AFCI's (Arc fault breakers). They are required at the breaker panel on almost every circuit in residential installations these days. (They've been required since 1999 in bedrooms, but now are required everywhere). I hear they aren't a requirement yet in the UK, I presume because you guys protect all cables with metallic sheathing.
In any case, studies have shown that around 50% of electrical related home fires in the U.S. are a result of arc faults (series more than parralel) hence the new requirement. Here most homes use non-metallic plastic sheathing rated at 90C. While it's safe cable, it's still non-metallic sheathed meaning it is feasible that it can be damaged in the wall (errant nails or rodent chewing), thus the potential for unseen arcs which normal breakers won't detect.
Some metro areas require metal sheathing for residential applications. Chicago is one city with very strict standards in that regard. (Here states and local munincipalities have the authority to override the national code with their own code). It makes sense in those areas because if one condo or apartment building burns, the whole block burns. It doesn't make as much sense in the country where your nearest neighbor is a mile away.
We also have many very old homes here. It is not uncommon to see old homes with "knob and tube" wiring from the 20's. It is legal, but if renovation is done it must be brought up to code. And we have tons of homes from the 50's to 70's using wiring code from back then. Grounding has been code since the early 60's I believe, but there's still many homes out there without an earth ground circuit (all receptacles are two prong). Some unscrupulous people will install 3 prong receptacles in an old home without a ground circuit, thereby creating a "bootleg" ground. This is achieved by connecting the neutral to the metal electrical box. This will trick the inexpensive receptacle testers into reporting there is a proper ground. These cheap testers are used by most home inspectors, and creates a dangerous situation for an unknowing home buyer.
Excellent- thank you 👍
Excellent explanation!!! Thank you
Great explanation. Thank you!
Good explanation!
Excellent video, as usual.
Excellent explanation, thanks
thank you for your lessons :)
superb video
Clearly explained as always.
Thanks so much , my broken underfloor heating caused me issues and was tripping the other RCD circuit confusingly, Just disconnected from the thermostat and all good now.
Cheers. Excellent explanation. This had me puzzled while doing some electrical work up in my gran's attic, I thought she was flipping the main breaker as she's terrified of electricity. I'm cautious; test with a NCV tester then a multimeter before work especially as whoever did the wiring in that attic had no idea what they were doing, flourescent strip light in *series* with a ceiling rose (not for lack of wire, they just left the live wire flapping in the breeze),steel cored speaker wire (or something similar) hooked up to live and neutral leading to seemingly nothing, if I had to hazard a guess it was for an old doorbell and just reconnected by every contractor who did some work there, though why it is on the attic lighting circuit is beyond me.
All of these things had me fairly worried about the house being plunged into darkness as I was concerned that there was a live (or intermittently live) conductor somewhere. Turns out it was neutral touching earth, which I'm sure of as I tested it twice. Measured with a multimeter and got .7 volts, guess the current was enough to trip the breaker though.
I've had this happen when I made up an adapter for a caravan to run on a regular 10amp NZ socket (for the lighting and light loads). The caravan fuse box had a linked neutral and earth bar and would trip the RCD when plugged in. I had to remove (cut) the earth neutral link while still keeping the earth neutral wires connected to the plug on the caravan
Excellent video ! Thanks .
That was really informative ... I was facing same issue . ..
Great video.
Thank you
This is gold!
Excellent video very easy explanation
Thanks John
Hello,
Excellent video, as usual.
Could you please do a video on RCBOs, and particularly on why they have the separate white earth leads. I am a trainee electrician, and was told by one qualified electrician that they are to prevent nuisance tripping, but another qualified electrician didn't know what they were for
The white lead is an earth connection and it is usually used by the TEST function of the RCBO... which creates a deliberate imbalance to earth in order to cause the RCD part to trip. If you don't connect it, the TEST function usually doesnt work. Some RCBO's are designed so that they don't require that earth connection
Great video, Thanks
You are the best. Thank you 🙏🙏🙏🙏🙏🙏🙏🙏🙏
Good teacher.
Very informative video John, and explained extremely well.
Great videos John. Currently got this problem and after disconnecting and replacing all neutrals got the problem down to sockets in lounge but cannot locate where problem is by removing each socket as all wiring looks ok. Is there a possibility that it could be a faulty MCB.I am in UK. Thanks
When making alterations to a circuit covered by a shared RCD (i.e. split load board), I will now disconnect the L, N & E of that circuit to prevent nuisance tripping as well as being a means of isolation. It will need to be done for dead testing anyway!
Great video ! I just saw it and I think one solution for this is to use 2poles or 1p+n MCB s instead of 1 pole. So when you disconnect the MCB both line and neutral are off . The regulations in my country recommends to use that kind of MCB s.
Of course RCBO s on all circuits is the best solution but it is more expensive.
In NL we use one RCD for every 4 MCB's. And indeed 2p RCD's. They recommend RCBO's for outdoor units like airconditioners, outside lighting and solar panels.
Where you from ? Romainia ? They use cow shit to build houses
Hi, Robert come lately! Thanks John, very clear explanation. BobUK.
Brilliant! Thanks.
I faced this issue last month and was surprised that even though Sockets MCB is turned off , why does RCD trip whenever Neutral touched Metal/Earth...Thank you very much for your videos
Excellent explanation 👌 thanks.
Pls John can you pls explain about generator "floating neutral and Bonded neutral".
Been there and done that - I was rewiring a socket and I twisted the bare ends of the cable together and the RCD tripped as explained plunging the building into darkness. The situation was only saved as I had a head torch in my pocket that I was able to find in the dark. Moral carry a torch at night particually when working on electric circuits.
Is there any way to simply determine if it's a 'neutral to earth' / 'live to earth' / 'live to neutral' fault that trips the downstairs light breaker?
Cheers for advice.
Thank you have really explained it very well, I think I can now solve my problem :)
Really excellent video
Thanks for big bulk of information
Mr.John please help understand me. With regards to rccb that is too sensitive when lightning occurs.
whether grounding is not good enough or there is another reason.
Great film
Hi John would a quick way to identify the problem be to remove the neutrals at th fuse box one at a time thanks
Only one word. Class!!!!
if i am replacing a light fitting on an individual circuit containing several lights ( and ive isolated it and made it safe) and i know its going to trip the rcd to other circuits which will bring a shop to a grinding halt, which conductor would i reconnect first to prevent it tripping and then in which order after that (to reconnect the other two).
also could you explain why they are reconnected in that order. thanks John, i hope the question makes sense
Very helpful
@John Ward
I stand corrected. I agree there should be a common neutral bar for the neutral connection of all loads controlled by this RCD. But I believe this neutral bar should be unique to this RCD and should not be connected to the neutral bar where the incoming neutral and non-RCD loads are connected. Please confirm.
What you're saying is that double pole mcbs are the way to go (especially since they exist in slim form factors), so that I can also isolate neutrals. The system of only disconnecting the line is a pain in fault-finding
thank you 👍👍👍
thank you J. i suddenly have a short between E and N after fitting a new wire. Unsolved for a week now. Have to locate it tomorrow.
Can you tell me how are surge suppressor installed? I mean those the look like rcd and are attached to the board. Thanks for your wonderful videos.
JW Ive been wanting to get a Fluke 1653B - to test systems here in the US... But now we have ARC fault breakers - will this damage the meter in anyway? I was wanting to do a trip test and get a time/ amp reading on each 120vt circuit here in the US , any advise ?
Hi,is that neutral "u" link a standard ulink or have you made it,and what diameter is it.thank you.
I agree very informative video.
Mike bkk
Very clearly explained I like this. :-)
Brilliant!!!