Query on recent Electrical Certification for property

[Julie.]

He says the Zs are too high though, not too low?? Which row is that on the report?

EDIT: Okay House sockets is the 2.1. Kitchen sockets is 0.00, so yes, that would be tripping the breaker repeatedly right, because it's a short circuit? The tenant would certainly have noticed and reported that. Pretty poor that the unit of measurement is not stated too.

In his point 2 he mentions two things, ir at 0.0 (which is wrong) and the high Zs - he doesn't mention the value here, but it is in the table of test results under "measured Zs" at 2.49 ohm. This must be less than 1.1 ohm (max permitted Zs) for this circuit, which it isn't hence the high Zs comment.

His ir at 0.0 is actually both 0.0 and 2.1 somethings in the live-earth column

It cannot truly be 0.0 as this wouldn't just operate the RCD, but would be a major "bang"

I suspect he measured it on the IR setting and never actually measured it again on a more appropriate range.

Technically it is possible to get 0.0 but not trip, as the normal voltage is 230V whilst the test voltage is 500V - so 500V could cause an arc, and show as a short, but 230V may be insufficient to arc, and therefore not trip - although technically possible it's practically unlikely.

 

[westward10]

Strictly speaking exceeding 1.10 isn't overly relevant as it has RCD protection but nevertheless it is too high and likely to be a result of the r2.

 

[Julie.]

Strictly speaking exceeding 1.10 isn't overly relevant as it has RCD protection but nevertheless it is too high and likely to be a result of the r2.

Yes, but it's clearly actually faulty wiring, rather than just being unable to bring the Zs in line.

So I would class it as a C2 anyway - I suspect someone has changed a socket or something and not connected the CPC correctly.

 

[JamesMDyson]

This is the report when it passed. He's left his original comments at the bottom. You will note some very strange things:


1. 32A Cooker BC still in place.
2. 3 of 5 RCDs still over 40ms at 1x. 2 have reduced to 39ms at 1x.
3. I have asked the tenant for a picture of the garage distribution board cable to see if it's been glanded.

Clearly either the report is a bad copy and paste, with some things changed and some not, or work hasn't been done.

 

[JamesMDyson]

32A on a 10mm is completely fine, no idea why he’s put that down as a C2.

RCD trip time can be up to 300ms, so the 40ms trip time is fine, again not sure why he’s put that down as a C2.

If the SWA hasn’t been glanded the yes this warrants a C2 and will have to be done.

Something that isn’t making sense is that he’s saying there’s a dead short on L-E on your sockets which would mean that your breaker would be going bang every time it’s turned on, which I’m guessing it doesn’t because you would know about this.

This guy either isn’t very experienced with testing or he’s trying to milk money out of you. The only 2 things on there that have to be done are the gland for the SWA and the alleged socket fault, all the others are only C3s and therefore only recommendations. The RCD wouldn’t even be a C3 because it trips well within the maximum time of 300ms so that shouldn’t even be on there

The company sent me an e-mail saying that the guy who did this report has since left. He also suggested that the x1 and x5 results were transposed, i.e. the 23ms results were for 1x and 54ms for 5x. From what I understand about protection devices, this seems very wrong. Or am I wrong?

The address on the form for the company is also different to the one registered at NAPIT?

Is there a governing body for electricians?

 

[JamesMDyson]

I have photos of the garage cable (item 1) in the report but very small.

View attachment 108442

These are current pictures. You will note that the 32A B32 breaker and original RCD is still fitted.