Global IR testing on 3phase

[TJC1]

Evening all

Does anyone have any advice or methods for global testing on a 3phase consumer unit?

Cheers

 

[Lucien Nunes]

It's no different to single-phase. For commissioning (and EICR if you can be sure all loads are disconnected) test each wire to each other wire. For EICR with loads still assumed to be connected, three lines and neutral paralleled to earth.

 

[pc1966]

Often the isolation switch for TPN is not neutral-switching, so you may need to remove a link or similar.

Take care there, just in case neutral is not quite so neutral as you thought!

 

[Lucien Nunes]

It's a very good point. When I open a neutral link for testing, especially if it is going to be left open for a while, I put a reminder on the isolator lockout so that it does not get overlooked when re-energising. I have never powered a system back up with the neutral open, but having spent many hours repairing the aftermath of neutral loss events, I don't want to cause one myself.

 

[SparkySy]

I have been guilty of the above in my youth and forgotten to re-connect the neutral. It cost me a load of 400w ballasts! I learned some new words that day from my boss at the time!