How would you advise customer

[The Ghost]

Why are you disconnecting cpc in cu for IR

Well I just removed the whole lighting cable and tested IR from CU end so LNE were disconnected

 

[bigspark17]

Well I just removed the whole lighting cable and tested IR from CU end so LNE were disconnected

Cpc should remain in MET during IR testing. As for your situation i would back the way you approached it

 

[The Ghost]

Cpc should remain in MET during IR testing

Really? Never been taught that, why is that then wouldnt it provide voltage onto other CCT's?

 

[Pat H]

I would only remove CPCs while testing new circuits I've installed. If the installation isn't mine far safer to leave CPCs installed.
And know as long as Ze is good all others circuits should be safe.

 

[The Ghost]

I would only remove CPCs

Yes but dont forget I was only checking the lighting circuit in particular and the other circuits were on.

 

[HandySparks]

Really? Never been taught that, why is that then wouldnt it provide voltage onto other CCT's?

See 612.3.1 of the current regs: The insulation resistance shall be measured between live conductors and between live conductors and the protective conductor connected to the earthing arrangement.

If the line and neutral are disconnected, there's no reason that any test voltage would affect other circuits. However I would avoid IR testing with other local circuits energised.

 

[The Ghost]

connected to the earthing arrangement

Wow thanks, well I have learned something today. P.S. I did actually look at it, mustnt just follow OSG then.(note to self)

 

[bigspark17]

Yes your testing your line conductors aggainst earth, do you identify each cpc and diconnect when IR testing? If so must have taken an age to do.

 

[Risteard]

Wow thanks, well I have learned something today. P.S. I did actually look at it, mustnt just follow OSG then.(note to self)

That requirement came in with the 17th Edition in 2008. Without the earthing arrangement being in place and the cpc connected to the MET then you may have a fault between live conductors and earth but not to the cpc of the circuit.

 

[The Ghost]

connected to the earthing arrangement.

Not usually I start with testing all together and only break it down if there is a low IR, as I say I needed to separate this circuit in particular. It was a one off really.