EV charger causing ground overheating

[littlespark]

I hope that red and black aren’t connected to anything.

I can see you having to make a much bigger hole than that.


Keep us updated, this one is really interesting.

 

[redfox88]

They’ve found problem with the neutral and are now stripping everything out and replacing everything their side.

Are the red and black cables on my side of the supply?

 

[LewisM]

How dense can you be to do that to a fuse and electricity meter

 

[littlespark]

The photographs aren’t clear enough to show how the old red and black are connected.

I’d be very surprised and somewhat shocked if they’re floating about live there.

Ask the guys doing the fix how bad it is….. we can explain any technical words they might use.

 

[timhoward]

Are the red and black cables on my side of the supply?

I'm fairly certain that they won't reconnect until they have checked as far as the meter connections, and in the course of doing this it should become clear what is going on.

 

[redfox88]

New fuse and meter supplied and readings they’re getting all good.
Their only comment was on the earth cable going from our unit into theirs, that it was too small but not major. Something to fix whenever electrician is out again

 

[Lucien Nunes]

Good stuff. So that leaves the question of whether any of your wiring was damaged by the diverted neutral current. What were the original symptoms exactly?

 

[redfox88]

That will be the next step yes. Initial assessment only shows damage to one particular outlet feeding one particular gas boiler appliance.
That appliance should have been earth bonded but it wasn’t. Perhaps why it was the victim or some other strange reason.
Will get that bonded, earth swapped at the meter and maybe a full survey of the inner set up. Electrician wants to rewire the board too and feed 6mm cable into the kitchen as everything bar the oven seems to be running off 1.5mm. Not sure if that’s from previous diy rewire or if it’s original cable.

The main thing is that this major issue is solved now. Takes the pressure off a little and can sleep a little better.

Any tips for what I can and can’t do to repair around where they’ve installed the new equipment?
The backer board is hideous and there’s still gaping holes around it

P.S thanks to everyone’s input on this thread. Ye saved me an absolute headache

 

[littlespark]

Would have liked a service isolator fitted to make it easy to change that board in future.

 

[LastManOnline]

Going to tag @LastManOnline in this as I'm certain he'll be interested in learning more about it.

Completely in agreement with all previous comments regarding DNO,s neutral.Its pretty certain that this house still has metallic services which are giving an excellent return path via the neighbours bonding.

 

[Lucien Nunes]

That appliance should have been earth bonded but it wasn’t. Perhaps why it was the victim or some other strange reason.

It's a likely contender if it is connected to metallic water or gas mains that were providing the best earth path after the CNE broke open. As you say, adequate main bonding would then have prevented damage to the wiring by diverting the current along a much heavier conductor. But... would you have discovered the problem in that case, or would the pipework have been left carrying the entire house load current for the foreseeable future?

Some of us here are not huge fans of TN-C-S, even in its PME guise.

 

[redfox88]

We also found that when we had the combi boiler installed early last year and new pipework done to meet spec, that the gas engineer never did any earth bonding on those pipes, nor did they say anything about needing to do it.
We also don't believe gas is earth bonded at the mains, despite certs from electricians, including more recently the EV install cert, claiming it is.

Strangely enough, networks called again today to upgrade the meter they installed yesterday to a new smart meter.

Recommendation again is to attach more sufficient earth cable from us to them, but also replace the black and red mains cables, the luxury for which will cost €160 for them to call out while that work is being carried out...I think that's what I read from the conversation any way. But he said the red and black were large enough for this not to be done immediately, although its near top of the list now with everything that's happened recently

 

[Lucien Nunes]

Under the current regs, when all relevant circuits are RCD protected, the requirements and necessity of supplementary bonding e.g. around the boiler are largely eliminated. But where there are extraneous metallic service pipes, which it seems you might have, main bonding is mandatory and all the more so with TN-C-S supplies.

 

[plugsandsparks]

Not withstanding what was a dangerous installation regardless of the EV charger, am left wondering why the EV charger did not detect an open PEN and shut down or at least there should have been a rod for the EV charger.......... think the OP would do well to get an electrician to go through the install with a fine tooth comb

 

[Lucien Nunes]

From the charger's point of view, it wasn't open-circuit. There was still continuity, just via the wrong conductors. There would have been extra voltage drop on account of their smaller CSA but perhaps not enough to signal an abnormal condition

 

[Lucien Nunes]

Deleted... duplicate post

 

[plugsandsparks]

Suppose it depends how it has been implemented in the EV charger. With what the OP was saying about hot earth cables around the property, i would expect to see unusual voltages and currents as measured at the EV charger, The Zappi for example has that many reference points built in to the charger that it has occasion shut down when there was no PEN issue, lol - Still think its one to note

 

[Risteard]

New fuse and meter supplied and readings they’re getting all good.
Their only comment was on the earth cable going from our unit into theirs, that it was too small but not major. Something to fix whenever electrician is out again

The EV chargepoint shouldn't have been installed if the main protective conductor (neutralising link) was undersized. This should have been rectified first.

 

[Risteard]

Not withstanding what was a dangerous installation regardless of the EV charger, am left wondering why the EV charger did not detect an open PEN and shut down or at least there should have been a rod for the EV charger.......... think the OP would do well to get an electrician to go through the install with a fine tooth comb

PEN fault disconnection is not a requirement of I.S. 10101.

 

[davesparks]

Not withstanding what was a dangerous installation regardless of the EV charger, am left wondering why the EV charger did not detect an open PEN and shut down or at least there should have been a rod for the EV charger.......... think the OP would do well to get an electrician to go through the install with a fine tooth comb

There are differences between Irish and UK regs and as far as I know an earth electrode is required for the whole installation under Irish regulations when a TNCS supply is used.