My electrician wants to remove the inverter's supply PE and...

[Joules]

...Replace it with a connection to a ground spike via the heat sink.

The 1.5kW GTI has no off grid capability.

This separates the house PE from the inverters but is it the right thing to do?

New to the forum, this is my first post.

 

[davesparks]

This sounds dodgy to me.

Do you have any more details? Why do they want to do this?

 

[Joules]

This sounds dodgy to me.

Do you have any more details? Why do they want to do this?

Its complicated...The DNO supply is TN-C-S, recently a ground spike was connected to the GTI and it operated without problem. During renovation and unknowingly the PE to the incoming copper water pipe was cut. This manifested itself as nuisance tripping of the consumer unit RCD. When the spike was disconnected the nuisance tripping went away. The sparks is due to reconnect the water pipe PE next week. It seems the only way the TN earth could connect to ground was through the GTI supply cable and its earth wire. I agree disconnecting the GTI earth is suspect it will remain connected; the ground spike will remain disconnected. I'm hoping to have it repurposed as a supplemental PE to the DNO earth in the meter box.

 

[UNG]

Have any checks been done on the incoming supply and also the inverter output, it seems odd that your installation is relying on a metal water pipe for an earth and would possibly suggest a floating neutral and it is the water pipe that is giving it an earth reference
I would suggest it is a back to basics approach and check the incoming supply and maybe a check at 1 or 2 neighbours if you can, I suspect there is a DNO fault outside your property on the local network
With regard to making your earth rod a supplemental earth to the MET while the idea has some merit it could mask any future faults on the local supply network and your rod could become the main earth point for a number of adjacent properties and potentially end up carrying quite a high fault current. I have seen the same set up a few years back where an electrician couldn't be bothered calling the DNO about an earth fault and instead installed a rod and connected it to the MET the result was 6 -8 houses were earthed via that rod with a Ze of 37Ω