failed Zs

[Deleted member 9648]

I agree with you on new builds, should be designed to trip in time regardless of RCD. You would still need to carry out the test though to confirm CPC is continuous.
I was replying to nicsin02 (not great at this forum thing!):
I am just going to put these Zs fails a C2 fault and recommend the mcb get downgraded to either 16/20amp, I've always been led to believe that a 30mA RCD is for additional protection on a TN arrangement, I do alot of new build house tests where the full d/b is RCD protected and it would make the Zs test pointless if I went down the line of relying on the RCD for tripping times? !):

It can be either additional or earth fault protection,have you looked at 411.4.4?....which deals with TN systems.
And a new installation and initial verification is a different animal to an EICR....where the only consideration is compliance with 7671.

 

[ojchurch]

It can be either additional or earth fault protection,have you looked at 411.4.4?....which deals with TN systems.
And a new installation and initial verification is a different animal to an EICR....where the only consideration is compliance with 7671.

Maybe I haven't been clear, sorry, I don't often post on forums so am probably not used to the etiquette etc. I was responding to nicsin02's post which I then edited in after. Must get used to these symbols on the mobile format, reply with quote isn't obvious there.

I am fully aware what regulation 411.4.4 says and if I was carrying out an EICR to BS 7671 I would pass the circuit in question as long as all other requirements were met. Also obviously I would have to be sure the high reading was legitimately down to the combined cable runs & not other reasons. I would however detail my findings in the report and try and explain to the client in laymens terms what I had found and the ramifications.

I realise now that I didn't read the post correctly, I was on a tea break! I was trying to say that you still need to confirm continuity of CPC but nicsin02 was talking about not having to take the EFL reading, not confirming continuity of CPC. My bad.