IR testing on CU upgrade

[Risteard]

Inapplicable could apply to all of the test results for out going circuits when conducting a CU change.

Not all of them as you need to verify that you've correctly reconnected them and that ADS will operate. Certainly some of it may not be applicable though.

 

[TJ Anderson]

Inapplicable could apply to all of the test results for out going circuits when conducting a CU change.

As above. Circuit protection is often altered in these upgrades. (3036 to 60898 OCPD's for example) so to confirm ADS, Zs would have to be taken and recorded as a minimum. Additional protection by RCD may well have been added too and these would also need testing and recording to prove satisfactory.

 

[Dave OCD]

I always test each circuit individually and record all Insulation Resistance and Zs values when doing a CU change,as well as the RCD/RCBO operating times,Ze and PSC etc, surely that's the right way to prove the circuits are safe for reconnection ?

 

[TJ Anderson]

I always test each circuit individually and record all Insulation Resistance and Zs values when doing a CU change,as well as the RCD/RCBO operating times,Ze and PSC etc, surely that's the right way to prove the circuits are safe for reconnection ?

Yes mate, me too, that's doing a thorough job.

 

[Baddegg]

Me as well Dave, takes me longer but I sleep better....

 

[Deleted member 26818]

As above. Circuit protection is often altered in these upgrades. (3036 to 60898 OCPD's for example) so to confirm ADS, Zs would have to be taken and recorded as a minimum. Additional protection by RCD may well have been added too and these would also need testing and recording to prove satisfactory.

If you’re changing from BS 6036 to BS EN 60898, then you should be checking Zs beforehand, especially now we have Cmin.
Yes, if you’ve installed RCDs, they will need testing, because it’s part of the work you have done.