59 minutes ago, Mattg4321 said:

Does your RCBO also disconnect the neutral?

Are you in close proximity to other properties and their electrical installations that may now or in the future not have a TT earthing system?

2 pole RCCBO so yes?

Not it sure what constitutes "close" but nearest property is +30m away.

The earthing thing with car charging interests me. As I understand it the issue is that as the neutral and earth are actually connected at the service head if the neutral in the mains were to become broken then anything earthed could become live? The solution is a device that checks if this is the case (not sure how) and disconnects line, neutral and (unusually) earth if that occurs. Is that right?

It’s (PEN faults) not a problem isolated to EV charging, but one that it has been decided is of a particular risk when charging cars.

If there is a fault with the PEN conductor you lose the earth and neutral and all Conductors rise to 230v potentially. A particular risk outside any equipotential zone. The PEN fault protection measures the voltage difference between line and neutral and disconnects all conductors if it’s not circa 230v.

1 hour ago, Mattg4321 said:

It’s (PEN faults) not a problem isolated to EV charging, but one that it has been decided is of a particular risk when charging cars.

If there is a fault with the PEN conductor you lose the earth and neutral and all Conductors rise to 230v potentially. A particular risk outside any equipotential zone. The PEN fault protection measures the voltage difference between line and neutral and disconnects all conductors if it’s not circa 230v.

Thanks.

Wouldn't a TT earth system guard against that as the earth is effectively separate from the neutral. If the combined earth neutral failed say in the road, there would be no connection between the line and the earth so it would be like a switch going open on the neutral side of the load. The earth bonded components in the system like pipes, casings and car bodies would still be at local earth potential?

It seems the charger has that protection as it has a display for earth fault and codes for either voltage over 253v and one for under voltage (doesn't say exactly what that voltage is).

Yes, no need for PEN fault protection on TT systems with no other potential TN systems in close proximity.

2 hours ago, Mattg4321 said:

Yes, no need for PEN fault protection on TT systems with no other potential TN systems in close proximity.

That's what I thought.

So aside from the slight oddity of a 32a outlet rather than a 16a or 13a in a 20a radial it looks allowable (and more importantly - safe)