Query on recent Electrical Certification for property

Uplight99 · May 27, 2023

JamesMDyson said:
Where is that time stated on the report?

EDIT: It's okay I see it now.

This is the relevant part of the wiring regs isn't it?

https://electrical.------.org/wirin...nges-to-rcd-testing-in-bs-76712018plusa22022/

Huh, link won't post.

View attachment 108444

So the test results show 54ms at 1x and 23ms at 5x, which as you say are both well within the 300ms (1x) and 40ms (5x) in BS7671.

Thanks

Since amendment 2 we only have to carry out the RCD test on 1/2x and 1x. 5x is no longer a requirement

JamesMDyson said:
The test was done 10/08/2021 according to the report, so pre-Amendment 2 (28/03/2022). Although the date doesn't really make sense either because the invoice for the work wasn't charged to the owner until Feb 2022, unless maybe the work was postponed due to lockdown following the initial test?? The reason we're looking at it now is because it's very much only the tip of a larger iceberg.

I would question the things that have been mentioned to be only a C3.

The thing that’s probably going to cost you the most is the the fault finding

Petej999 · May 28, 2023

JamesMDyson said:
A relative recently had an electrical certification done on a rented property. The property was build in 2005 and had previously passed 3 electrical certifications with flying colours, however this time round a number of issues arose resulting in a bill of £500, which was very surprising. Several issues, such as RCDs I can trace back to the 2018 changes to the wiring regs, however there was mention of wires terminated incorrectly and needing glanding, which seems strange given that they passed 5 years ago, unless all the previous 3 were wrong. Additionally the cooker was on a 32A circuit breaker, and the engineer said it needed a 40A breaker?? There has been no problems with the 32A breaker tripping, so why was it necessary to increase it to 40A?

I had other issues with plumbing work done by the same outfit following the installation of an electrical shower (it leaked and then leaked after he allegedly fixed the leak). Could you help explain the changes?

need to pass this report onto the property owner he/ she is the one res[onsibl

cliffed · May 28, 2023

Bit picky I’d suppose but thinking this is wrong too.
Personally the details here would only be the Main Switch, I would put the RCD on the schedule results page.
I take it’s a Split DB configuration

[ElectriciansForums.net] Query on recent Electrical Certification for property

JamesMDyson · May 28, 2023

Uplight99 said:
Since amendment 2 we only have to carry out the RCD test on 1/2x and 1x. 5x is no longer a requirement

I would question the things that have been mentioned to be only a C3.

The thing that’s probably going to cost you the most is the the fault finding

The work has already been done. The guy has been doing all fixes, electrics and plumbing on the property, which is managed through an estate agent. Basically, they chose the contractors. Since Feb 2022 the charges for repairs amounted to £1400(!) on an 18 year-old property, not including EPC and gas certificate. The owner is changing estate agent as a result, but the estate agent defends the contractor to the end and is convinced there isn't a problem and is charging a large fee for the transferral of management. The owner's position, and mine, is that the estate agent has 'substantially failed in their duties' by not finding out last year (when it was first queried) what I found out in a single day, and also not seeing the general problem with the quantity of repair bills on a relatively new property as well as the faulty shower work.

Our main concern now is whether the work he's done is up to scratch, or is that faulty too?

JamesMDyson · May 29, 2023

Julie. said:
2 - this aligns with the test report figures, so firstly it looks most likely that a socket outlet has been changed, or whatever and the earth connections haven't been made correctly, this would be a valid unsatisfactory on the report, secondly the low IR reading is difficult to understand, he gives a value of 2.1 somethings! If those somethings are Meg ohm then actually it's technically a pass. If they are k ohms, that's a genuine issue, wouldn't trip the rcd, but is a valid C2, if ohms (which he implies), the rcd would trip all the time.

Okay thanks.

Julie. · May 29, 2023

JamesMDyson said:
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 · May 29, 2023

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. · May 29, 2023

westward10 said:
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 · May 31, 2023

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 · Jun 2, 2023

Uplight99 said:
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?