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Is that still true today, post 18th edition, and if so does this in fact render PodPoint's attempts to invent a magical open neutral fault detector totally irrelevant, if the IET CoP mandates an earth rod anyway?
Third edition CoP (published 2018, aligned with 18th edition) says:

For single-phase installations, a voltage-operated device that will meet 722.411.4.1(iii), when and if available, may be an appropriate solution. (At the time of writing these devices are not available).

So it all comes down to whether PodPoint's device actually satisfies 722.411.4.1(iii).

As previously discussed, in my opinion it is not possible to do so without having an earth electrode - though a device based on monitoring the supply voltage only might provide a sufficiently large proportion of the safety benefit to make it a good idea, it doesn't meet the requirements specified in the regulation.
 

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Good geographic spread of practical experience. Gault (OK IoW specific) is in the range up to 20 ohm.m resistivity according BGS so ties in with your comments but sulphate content can make a big difference, bringing the resistivity down, any issues with concrete attack locally?. I'm guessing some of the West Cornwall sites were challenging but again once shouldn't generalise and the local soil conditions if there is any and shallow geology makes the difference. Fancy doing any TT installations where the geology is Lewisian Gneiss.
I'm pretty sure that the top metre or so of soil is what really determines the resistance of the electrode, and that seems to be borne out by the way the DNO install their earth electrodes. A typical local transformer earth will be a shallow buried earth mat, maybe a metre or so down. Same goes for the intermediates that I saw going in last year, they were all shallow buried grids at the base of the poles. The last couple of underground pot joints I've seen being made off also included a horizontal copper earth strap laid along the cable trench.

Many years ago, when pretty much all houses in the UK had TT earth systems, the use of copper rods, straps or mats seemed to be quite widespread. I remember the house I grew up in having the earth electrode copper strap running down the wall and presume that it just went down, and maybe along, the foundation trench. Often these older houses just used the incoming galvanised iron water pipe as the earth electrode.

Interestingly, TT earthing is still mandatory for all temporary supplies everywhere in the UK, even where the incomer has a PEN with a low Ze. I encountered this when building our house, as I installed a fence-mounted meter box when we levelled the site, so I could get power in early. I decided that putting a permanent supply in from the start would be cheaper (only one connection charge) and when the DNO chap came to connect us up he refused to put the fuse in until I'd banged in and tested a rod. The daft thing is that he then measured Ze of his installation after he'd finished, and scribbled it in felt pen inside the box, with a note reminding me that I wasn't allowed to connect the site supply CPC to the incomer PEN, but had to use the rod I'd driven in maybe a foot or two away from his underground cable joint (with it's trailing copper strap intermediate).
 

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Recently they renewed a lot of power poles around here, and I noticed that they were putting in extra intermediates in at the same time. Seems to have had a beneficial effect, as our Ze has dropped about 0.1 Ohm since this was done
Could of course have just been reduction in the resistance of the phase conductor, given this was presumably replacing old-style 4-wire overhead with ABC (which, incidentally, reduces one of the more obvious risks of open neutral, with the neutral at the bottom of the 4-wire being most at risk of being snagged by something passing underneath).

Anyhow, your overall point is well made - it's always possible to achieve an adequate earth given the right techniques. It's usually cheap and easy, but there's always a risk that it might turn out difficult and expensive. And especially risky for someone from a national installer, travelling from miles away without local knowledge of the likely ground conditions and techniques.
 

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Quick related question, as so many electricians are on this thread. I have a 30A chargemaster (fitted circa 2014) installed on the outside of our integral garage, for charging cars on our driveway (not much chance of fitting a modern car in a 70's garage). An earth rod was fitted on installation.

I recently won a Zappi on ebay and would like to swap it with the chargemaster. I'd also like to move the chargepoint location to the inside of the garage, to reduce chance of theft, with the charge lead going under the garage door.

I plan to replace it and move it inside myself; it's only 3 wires after all. My question is; should I reconnect the zappi to the earth rod once it's inside the garage? I'm assuming the answer is yes but wanted to confirm.
 

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Could of course have just been reduction in the resistance of the phase conductor, given this was presumably replacing old-style 4-wire overhead with ABC (which, incidentally, reduces one of the more obvious risks of open neutral, with the neutral at the bottom of the 4-wire being most at risk of being snagged by something passing underneath).

Anyhow, your overall point is well made - it's always possible to achieve an adequate earth given the right techniques. It's usually cheap and easy, but there's always a risk that it might turn out difficult and expensive. And especially risky for someone from a national installer, travelling from miles away without local knowledge of the likely ground conditions and techniques.
Good point, they were fitting ABC at the time, seems to have been a general replacement programme, with the poles and overheads being replaced.

The point about a national installer is also a good one. There's really no substitute for local knowledge. I suspect there's also a more general issue with a lack of expertise in installing TT systems, though.
 

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There have been other threads on this. The electrician who installed my ChargeMaster unit said that he and his mates were up in arms as it now takes over half a day per installation where earth rods are required and this was affecting their bonus system (mine is in the garage so no earth rod needed).

I plug my motorhome into a garage socket which is far higher risk than charging an EV but of course it is not covered by the Regs.

My letter on the subject was published in the IET magazine with a response from the technical committee who, of course, said it was a safety issue. My question was more about probability and risk and whether the cost is justified.

A bit academic because if you have a PMS system the electrician has to do what the Regs. say. Whether it is worth correcting an older system is entirely a decision for a user but in some cases it may be more worthwhile to invest the money in other domestic improvements. My distribution board, for example, has ancient fuses and no RCD. I have had two fuseholders burn out over the years so an investment is well overdue.
There have been other threads on this. The electrician who installed my ChargeMaster unit said that he and his mates were up in arms as it now takes over half a day per installation where earth rods are required and this was affecting their bonus system (mine is in the garage so no earth rod needed).

I plug my motorhome into a garage socket which is far higher risk than charging an EV but of course it is not covered by the Regs.

My letter on the subject was published in the IET magazine with a response from the technical committee who, of course, said it was a safety issue. My question was more about probability and risk and whether the cost is justified.

A bit academic because if you have a PMS system the electrician has to do what the Regs. say. Whether it is worth correcting an older system is entirely a decision for a user but in some cases it may be more worthwhile to invest the money in other domestic improvements. My distribution board, for example, has ancient fuses and no RCD. I have had two fuseholders burn out over the years so an investment is well overdue.
If your charger is installed inside garage but cable and car can potentially be outside then earth rod still needed according to course I’ve just been on.
 

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If your charger is installed inside garage but cable and car can potentially be outside then earth rod still needed according to course I’ve just been on.
And then, in the event of an open PEN fault, with the car parked in the garage and connected to the chargepoint you can have a dangerous voltage between the car (earthed to TT spike) and the freezer (earthed to PME earth).

Has anyone thought of the similar hazard with metal outside water taps, connected by copper pipework to the inside water piping, which is bonded to PME earth?
 

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Has anyone thought of the similar hazard with metal outside water taps, connected by copper pipework to the inside water piping, which is bonded to PME earth?
Yes, it has been mentioned.

The only really safe solution is to make the whole property TT, so there is no risk of having two equipotential zones.
Relatively easy to do in many houses, but I don't know offhand what the pros and cons would be.
TN-C-S is supposed to be 'good', but maybe EVs will be it's downfall :unsure:
 

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For self testing is something like this useful for testing your own home. If a fault is flagged then call an electrician in.
 

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For self testing is something like this useful for testing your own home. If a fault is flagged then call an electrician in.
No. it'll just show presence of an earth not that it is ok or what type.

The only real way is with a proper MFT which is £700+

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