Insulation resistance test

[Newby2]

Hi, I just had a Mira electric shower replaced. It is a Mira Vie 9.5 Kw (electrical ELFI check less than 2 Ohms). The engineer issued me a safety advice notice with C2 potentially dangerous ticked. He recommends: electrician performs a insulation resistance test on wiring from MCB to shower. I wonder what this is about, and how much the cost likely is?
I live in Bristol. Thanks!

 

[Murdochcat]

Need more information really

What did the “engineer” actually do to come to this conclusion?

 

[Newby2]

I have no idea. He just installed the shower (I have used the same model for the past 4 years until it became faulty last week) and checked it's working ok without mentioning any issue. Then before he left, he told me due to regulation he had to issue this notice as a recommendation.

 

[Newby2]

I actually found out that 4 years ago when Mira installed the last shower (same model), they also issued a notice with C2 ticked, with the concern as "Fitted new 9.5kw Vie in place of a 9.5kw Go as a S&f".

 

[EFLImpudence]

Hi, I just had a Mira electric shower replaced. It is a Mira Vie 9.5 Kw (electrical ELFI check less than 2 Ohms).

With a 40A MCB, it should be around 1 Ohm or less.

 

[JohnW2]

With a 40A MCB, it should be around 1 Ohm or less.

Indeed, but this has obviously got nothing to do with 'insulation resistance'

 

[EFLImpudence]

Indeed, but this has obviously got nothing to do with 'insulation resistance'

Well - no.

I realise that that is the thread title but are we not allowed to comment on anything else?
Especially something which might actually be the "C2 potentially dangerous" part.

I do also realise that "1 or less" is "less than 2".

 

[JohnW2]

Well - no. ... I realise that that is the thread title but are we not allowed to comment on anything else?

Of course you are, but I was merely underlining the fact that the situation is very confused/confusing in terms of what we've said before.

As you have observed, in terms of what we've been told, the only thing seemingly 'wrong' is the apparently high Zs, which I dare say a good few would regard as deserving a C2. However, the OP almost got right the terminology for Zs/EFLI ("electrical ELFI check less than 2 Ohms") - which presumably means that the "insulation resistance" in both title and OP of this thread referred to something else - quite possible 'actual' insulation resistance ... but "why?" we obviously have to ask.

 

[Newby2]

sorry for the confusion. I am just repeating what is said in the report. Please see the report attached. thanks

 

[JohnW2]

sorry for the confusion. I am just repeating what is said in the report. Please see the report attached. thanks

Thanks. It's not your fault, so there's no need for an apology - that report says exactly what you have told us.

What it gives no indication of is why on earth the technician who wrote that believes an insulation test is necessary. There may be some good reason, but we have no idea as to what. If it were me, I think I would be asking them for an explanation before I had any further investigation/testing undertaken.

 

[Murdochcat]

I think some body is CTA

 

[Newby2]

sorry, Murdochat, how do you mean by CTA?

 

[EFLImpudence]

"Covering their arse" usually meant in a derogatory sense but in this case it would seem to be the correct thing to do.

 

[JohnW2]

"Covering their arse" usually meant in a derogatory sense but in this case it would seem to be the correct thing to do.

Maybe - but not particularly 'correct' if they think that an insulation resistance test is an appropriate thing to do to investigate a high Zs/EFLI measurement

 

[Murdochcat]

"Covering their arse" usually meant in a derogatory sense but in this case it would seem to be the correct thing to do.

Issuing such a document seems rather OTT without a proper explanation of what they did and for what reason …..

My guess is that they tested L - N and included an indicator light on the isolation switch

Does the circuit have RCD protection ?