just wanted to say thank you for providing one of the most concise and clear explanations of earthing structures

I’m an 18th edition apprentice and 3 lecturers have tried explaining this to me. Thanks for the clearest explanation I’ve had. Finally this makes sense. Thank you John Ward.

Thank you Mr. Ward even though i reside in the states your vlogs help me immensely.

Thanks for explaining the types of Earthing systems , Everyday is a electrical learning day!

Your videos are so thorough and articulate the subject very well.

Fascinating overview of how the UK system approaches electrical safety. I am in the US and I can now see the advantages to our system of having a center tapped neutral on the distribution transformer secondary. The earth (grounding) conductor is connected to the neutral at the entrance to the structure and there is an earthing rod driven at the structure.

What a legend. I'm doing my level2 electrical installation and types of earthing arrangements is part of the installation methods unit. the diagrams used by the college were usless so thanks for this...

In Germany you could find TN-C (older buildings) or TN-C-S (modern buildings) are the most common systems. But sometimes you could find TT, which depends on your supplier. The buildings with TN are fitted with an additional earthing rod for the cable failure you described at 10:48 min. Formerly they used the incoming water pipe, but now the most water pipes are made of plastic and the earthing rod is placed in the ground plate of the house (newer ones) or got a separate rod. And the most building connections are three-phase-current. The three lives L1, L2 and L3 all have 230V measured against N (or PE), but 400V against each other, so you've got two voltages in your system.

A clear presentation style going straight to the key points- a very refreshing change from some of the other vids I have seen! A thumbs up from me!

Bless you dude, I thoroughly enjoy watching your tutorials. They're very easy to digest. 😉

The explanation at the beginning, about the transformer grounding cleared up so many questions for me, thank you

What can I say John, except you have an excellent way of passing on the concepts in a simple and concise way. Call me a sado but I so much look forward to your articles.....

I commend you on the simple and clear demonstration of the variable systems. Well done.

these videos are so helpful. I've nearly completed my City & Guilds Level 3 Electrical Installation Diploma and this content is really helping with my wider understanding and prep for exams. I like your style of explanation, thank you.

Your videos are being great help and making it easier for me to complete my electrician course as I am totally new to this field Thumbs up

This is a fantastically straightforward and clear explanation of earthing. Thanks a lot, JW

Excellent video, for the first time really understand the three different earthing systems. Please keep up the good work!

Hi John, your videos are fantastic. I am currently doing a 2 1/2 week course in domestic installations - my instructor no doubt knows his stuff but dear god he does not know how to teach or communicate. I have highlighted the most important things for me to learn this weekend and you have addressed two of them in the last half an hour. Thanks!! :) *subscribed*

In Australia we have a MEN (multiple earthed neutral) system where the star point of the transformer is earthed and each house is supplied with active(s) and a neutral. At the main switchboard an earth stake is connected to the main earth terminal and a link is main to the neutral terminal. This means that any A-E faults will flow through the houses earth wires then go back on the neutral. If there is a fault with the neutral as well and it is broken then the current will flow through the earth stake to the transformer, providing the best of bot options 1 and 3 from the video.

Here in Norway the customer must provide an earth rod regardless of what system is being used. Even TN-C-S-systems must be connected to earth where the PEN is split to N and earth. So whatever happens to the earthing from the power company, there will be a local, good earth point.

when he said hello I'm JW.. you most certainly are John Wick with this... You my friend deserves a seat at the High Table. 👏👏👏👏

Just wanted to say a huge thanx to you. Very concise and descriptive and made what seems to be (sometimes) difficult to understand, understandable. Great speech and great use of visual aids. Thanx again😁👍

In Denmark the TT system is exclusively used. RCD are required on all installations which supply up to 20A, including old ones that was made before the invention of the RCD. It is the consumers responsibility to make sure a device has ground a connection, and it is only mandatory make the ground connection on domestic appliances.

TN-C-S is also the standard for system grounding in the US and Canada and has been for quite some years, except it is common for the main distribution board to have its own ground rod connected to the ground bussbar. The only other difference is that the supply transformer has a 240V center tapped secondary which is grounded and the end taps providing the 2 120V hots.

Thank you very much for a brilliant explanation.

Currently studying 17th edition and the earthing had me baffled but your video has cleared that up, great vid thanks

We have been "PME'd" here but my neighbour (same phase) is TT. My neighbour's system tripped (the voltage type you mentioned)but her fault also tripped an RCD in our property. Looking at you diagram, i think i can see how this has happened. Thanks you for such a clear explanation.

Thank you.. your videos are helping me massively with retraining as a sparky. I really appreciate you doing this for others to learn from :)

A Malaysia we follow UK specs most of the time (down to voltage and socket type), though most households here use TT earthing. TN systems are virtually unheard of.

Just found your channel. Many thanks for these videos. Extremely helpful.

As usual always very good and clear. I wish all explanations were this good. Thank you.

As an ex cable jointer I actually have had a shock from the N/E conductor of a 1ph concentric service cable! The shift electrician had attended a property and said there was no incoming supply. Labour team had been told to open an excavation over the service so I could cut and test. As soon as I removed the PVC sheath, I got a rattle. The cable had been damaged nearer the service joint and strands cut, water got in and the cable blew open circuit to the joint and phase to N/E towards the house! We weren’t issued with the much hated neon testers in those days. 😊

Thank you so much I'm doing my 2391 and I'm dyslexic so need as much help as possible and your teaching is amazing for me very clear and to the point thanks again 👍

Man, this is great- I subscribed and liked the video. Thank you very much!

In Australia, the Multiple Earthed Neutral (MEN) earthing system is used and is described in Section 5 of AS 3000. For an LV customer, it is a TN-C system from the transformer in the street to the premises, (the neutral is earthed multiple times along this segment), and a TN-S system inside the installation, from the Main Switchboard downwards. Looked at as a whole, it is a TN-C-S system. So, normally there will be a link in between the neutral and earth bus bars behind the switchboard, as well as at the local transformer.

What a cracking vid. Looking forward to watching the rest!

John, many thanks again for an very clear exposition. Well done.

Thanks for your detailed explanation. Something useful for those of us in Nigeria

Brilliant and very clear instructional video. Thank you John (liked and subscribed.)

Thank you. I've been searching answers about this for long time and now got them from you. I enjoyed your video.

Very informative - thanks John!

I knew JW was the place to come for this information. Looks to me that in the 'absence' of an earth, the neutral simply needs to be connected to the earthing cable inside the house at the board.

Probably the best explanation I have seen. Thank you.

Clearest presentation I’ve seen on this topic.

MEN is the standard here in Australia. It's a TN-CS system, with a separated neutral/earth bar arrangement, and a earth rod in the ground. We have to find resistance as low as we can get - typically 1-10 ohms. Some sites (Centre of the country - sandy country) can see earthing rods 10-15M in depth. We equipotentially bond everything to stop balance issues.

Thank you so much for providing these excellent instructional videos.

Another great video. Comprehensive, clear and concise.

Great videos John Thanks very much for your time and effort

There is a label on the cutout here that says "This installation is connected to a PME system" - so that confirms mine. A house we lived in before had a plate on the cutout saying "PME system" too. However, we also lived in one house where the supply came in from the poles, and that was TT. Our ELCB was a Chilton voltage-operated one.

I love it. It's like Hugh laurie swallowed the 17th edition. You rock

Thanks John,that was really interesting

Very good. Here in Australia we use the TN-CS system but the main earthing point is connected to an earthing electrode via the main earthing conductor and to the main neutral bar on the consumer side via a link which must be the same CSA as the incoming neutral. We call this the MEN link, and the system the MEN system (Multiple Earthed Neutral) as the neutral is earthed via the MEN link and in various points back to the TX star point. The consumer main neutral therefore functions as a PEN conductor. As JW mentioned, we do occasionally get instances of open or high impedance consumer main neutrals and shocks have occurred. RCDs clearly won't open as there's no current imbalance between A and N on the consumer side. There are also hazards if consumer mains are connected with incorrect polarity but RCDs (if installed!) will open if current flows to earth in these cases. Things are easier when you have only the one system! :o)

SSE are now installing more and more TN-S systems on new connections work. TN-S is now always used when connecting up metal clad buildings or connecting to the old PILC cables. Funny how everything seams to go full circle. As a cable jointer I personally think that TN-S is a better system. Really good vid by the way.

*_Thank you for this rather helpful tutorial!_*

We use TN-CS in the US but we additionally attach a bare wire from a ground rod at the electric meter to the earth terminal in the fuse box. We also run a bare copper from the rod to the nearest hose bibb, I think for discharging lightning. The plumbing would provide a path thru to the utility's piping system which used to be metal. It's probably changed since plastic supply pipes were introduced. Wait, many pipes from the 60's were asbestos-cement which i wouldn't think was conductive so I'm not sure of the system. They may have terminated with a ground rod at the water meter in that case.

so helpful. much respect to you sir.

Great video! Here in Denmark we pretty much only use the TT system. I'm not sure why... but i guess it's because the electric company like the idea that they won't have to be responsable of the PE connection.

Fantastic Video!!! Explained In Simple Terms

Thanks John , This is exciting ,I am starting to understand , may be its the white board but youve just broke a barrier . Before i know it I'll be wiring a plug !! Seriously, the other experts who try to explain should come down to our level and see what its like , its no fun down here ,but you obviously know a few thickos and kow whats required

great video, very clearly and well explained. However 2 points. Most of Northern Ireland (rural areas) are still in TT. My house built in 2006 was done in TT. Also when you say neutral is the same potential as earth. Must be remembered that in an AC system half the voltage is carried in the neutral and the lifter you get when you accidentally touch between neutral and earth is worse than live to neutral (or at least always feels much worse!) Overall, well done.

Thanks! That was extremely well explained.

Re supplying outside marquees etc from a TNC-S system - the danger would only arise if that supply came from BEFORE the "C-S2 split. Provided the supply to the marquee etc. is from AFTER the C-S split all would be fine- just like stuff in your house.

Thank you John ... perfect!

Here in Germany we use TN-Net, TT-Net and IT-Net. The TN is splittet into TN-S, TN-C and TN-S-C. We use normal 3 L Phase, some old houses have only one L Phase. The power cable come in house direct into a big fuse for every phase - at this point the 'Saved Earth' and 'Neutral' go to two difference lines. This place is the exchange point between the power company and my home power net. After this I must install the Watt-Meter from my power company. After this we can install every RCD how we want use ... Most older installation haven't one. For Thailand I not know the situation, we use there an own transformator ...

Very clear and concise presentation, thank you

You are clear and concise greatly appreciated

Great explanation!! In the USA we have 2 hot wires 120/240 and 1 ground/neutral the grounds and neutrals are bonded inside the main panel. The nec requires 2 ground rods for each electrical panel inside the house.

nice info about GND-earthing

A very interesting video, in my hobby (amateur radio) we tend to have grounding arrangements that attach to the shield of coaxial cable at the base of the aerial. This cable then generally connects to the equipment chassis within the house which is also connected via the standard mains lead to the standard domestic mains earth. In my set up the "ground mat" under the lawn is also bonded to the water piping of the house. It is a slight concern that in the event of a live-earth short in any part of the house a proportion of the fault current will flow through the equipment chassis to the " other ground". For various lightning protection reasons it can be very bad news to isolate the two grounding systems.. ie to provide a seperate safety earth only for the radio gear. This situation must be very widespread, presumably the answer is to make the bonding path as low resistance as feasible to minimise the current flow through the other path? We have an RCCB so presumably my question is more of a hypothetical one? Thanks for the video, most educational!

Here in the land of convicts and sea front properties the neutral wire often corrodes off in the outside connection box, we almost exclusively use M.E.N same as your TT supply but each customer has a removable link between the neutral and earth in the consumer unit for testing, this provides a limited path to the transformer when the incomming neutral fails.

Thanks, very clearly explained.

I've seen a few You Tube informative videos but this beats those hands down in presentation skills, clarity, knowledge and video quality. You should branch out into "How to make a You Tube video"!

There is another type of Earthing that you could of included. It is called PNB. Normally used for one domestic supply only to a single phase 11kv - 230 transformer where the earth for the transformer is via the neutral block on a 100 amp cut out connected by a 32mm covered copper wire to earth electrode/pin in the ground. Although historic, lots still exist and are in use in Dorset/Wiltshire/Hampshire and Somerset.

Great video great to understand more about earthing systems 👍👍👍

Thank you so much to the great explanation!!

JW god bless u for such good videos you really helping us to understand electric in easy way and a great help towards my electric course

If you like this topic , watch a video entitled "EW rice interviews Elihu Thomson " he's the engineer that came up with earthing " and maybe some others around the same time . Go to around 10.27 in the video and he states it was his invention for safety . I like the term you English use "Earthing " ,better than what we in the States use " Grounding " great video ps Mike Holt has good videos on this topic.

Thanks for another very informative video. Could I ask a question on TT earthing systems. Is it allowed in the UK to connect the earth rod to the neutral at the customer end, and what would be the result or problem if this is done on a TT supply. I believe that doing this would only help by tieng the two together and thus reduce any problem of poor earth rod resistance.

Clarity at last! Many thanks.

Thanks a lot John! Very helpful!

What a fantastic video, Thank you.

These videos are great. Very hard to get this information presented in an understandable manner

Very nicely explained, thank you

Hi John - Great videos, very informative - On this subject, on my house I seem to have a mixture of TN-S and TN-C-S. It looks to me as though the DNO have installed two cables in the TN-CS arrangement, and then AN OTHER has popped in an earthing rod for good measure (on a piddly little cable I may add). Would this be problematic at all do you think?

thanks for this excellent explanation,

Awesome videos, thank you. BTW South Africa works on the same systems.

Had a case where a screw shorted light switch switched line to earth. No RCD. Only symptom was the combi boiler kept tripping out on flame failure. Only when the Utility room light was on (not obvious at the time...) On inspection the live was 140v above ground at the boiler- flame failure detector required more! The earth spike was underneath patio paving, and may have been quite dry... On bright days there was no fault to find!

At 10:46 in that instance, where you show the break, the appliance would cease to operate as there is no return path (neither N nor E). The more dangerous situation is where the Neutral circuit is broken downstream (towards the transformer) of the closest earth rod, in which case appliances will continue to operate using the E path as return, thereby putting metal appliance and metal pipe surfaces at, or near, line potential.

Hi thanks for the time to make this video. Natural teaching

Brilliant presentation thank you

JW, could you expand further as to the earthing of a portable generator please? I use a 1kw Honda invertor generator on board our boat, generally for battery charging only. It represents a particular problem as afloat there is no possibility of an earth connection. The boat has a 240v shore power circuit on board which is generally connected to the mains supply in the marina when in the home berth. But when away cruising I plug the generator in to the shorepower inlet socket. Other boat users have suggested that the generator to boat shorepower connection cable should connect neutral to earth, infntbkniw what the thinking is behind this suggestion. Your videos are very useful indeed - keep them coming. Many thanks, Rob

I am proud of you sir thank u it is very help me with my electric course

Here our power company uses resistance grounding for some of their HT stuff, mainly the 26kV transmission they use. (I'm in the USA)

Sir, your explanation is wonderful. Also can you explain 6 types of earthing methods in more detail ?

Thanks for the video content that you provide

Hi JW very interesting I’m on the PME system For a couple of years now I’ve had the odd LED in the kitchen flicker .... but a couple of days before Christmas Day the lamp in the living room was flickering badly it’s connected along with my mother’s riser chair through a UPS and it was making funny noises so plugged the chair and lamp back into the wall socket and changed the lamp... Then on Christmas Day (2018) dinner out of the way we were watching tv when the RCD tripped switch it back on everything was fine for about 30 mins and it done it again this happed a few times through the night...( I had called my sparky and was coming out Boxing Day to have a look ) about 8am my UPS for my hard drives etc started going between battery and mains and very loud humming noises of the transformer inside the UPS Anyway sparky came out tested everything and put it down to a faulty RCD put another one in (not new) everything tested ok .... tried the old one in a test circuit and it tripped ! But as I was switching thing back on in the house came back out to speak to the electrician when I noticed a neighbour had an electrician in as well I told mines and he called him they were having the same problem as well so we called Scottish utilities they came out and was a fault underground .... I have since had the RCD that was put in go faulty again it wasn’t new plus was in when having problems ..... so new one installed so far so good But next week having a new unit installed with the new robc and a power surge on the supply into the house .... Great channel 👍

In Australia where I did my electrical apprenticeship, we have a far simpler system, referred to as MEN, Multuple eartherd Neutral. It is effectively a TT system as you have shown in your videos, but within the consumer supply location, the earth and Neutral are bonded locally. The "Multiple" in the name refers to the fact that every property provides an earth via a stake driven into the ground, which is bonded to that property's neutral It is surprising that the UK has insisted on allowing so many systems to be employed, particularly all systems you have indicated here can very easily be converted to MEN. It would make training and inspections far easier, and would create a commonality in the way earthing is undertaken. Having a local earth also ensures that there is always a safe path for fault currents, rather than relying on DNO provided systems.

Thanks John. You are a legend!

Great video that explains it very well

very clear and informative. thankyou.