Settle an argument please.

[nicebutdim]

I wasn’t at home during the inspection, SWMBO was and paid for the extra work.

I’ve taken a pic, but the pointless bit of plastic seems to have fallen off. It is inside the house so now danger of getting rained on. Having said that, as is often the case the architect slapped the bathroom directly above. Sometimes architects need a kid hard kick in the love spuds.

The wiring regulations specifiy an ingress protection rating for different aspects of distribution boards and this certainly isn't met. While there's no danger of it being rained on, and while there may be no realistic prospect of danger to anyone in your home, there are easily accessible live parts directly behind that new hole.

In short, the inspector has insisted on an apparently unnecessary derating of this circuit and in the process has left the installation less safe than it was before he butchered the cover, which is the very opposite of what any electrician is supposed to do.

 

[SJD]

As well as the correct type of MCB, I'd ask for a replacement undamaged cover to be supplied!

Out of interest, do you have the EICR that was carried out? It might be interesting to see (you can redact the personal details incl. those of the "electrician"'s).

 

[Phill104]

The wiring regulations specifiy an ingress protection rating for different aspects of distribution boards and this certainly isn't met. While there's no danger of it being rained on, and while there may be no realistic prospect of danger to anyone in your home, there are easily accessible live parts directly behind that new hole.

In short, the inspector has insisted on an apparently unnecessary derating of this circuit and in the process has left the installation less safe than it was before he butchered the cover, which is the very opposite of what any electrician is supposed to do.

The original installer has contacted me after I sent him the pic. Awesome guy. He has said he is going to come and replace the cover as he has a few of these boards in his spare parts pile. He is going to put the right breaker in and the only charge is the cost of the new breaker. I think I will owe him a few beers.

As for the EICR, I now feel I should complain but I am going to sleep on it first to get my thoughts together.

 

[James]

Thank James. That is why I posted, I felt a bit miffed. You can see just how wonky the fitting is. I haven’t looked but given how high the mcb is sitting I wonder how good the contact with the bus bar is.

Miffed?
i would be really pi55ed off about that if someone had done that to my perfectly good board in the name of electrical safety.
Unfortunately there are electricians out there that do not have a good understanding of the regulations and the thought that goes into making them.

instead of properly learning the trade and how to do it well they instead use some rule of thumb figures that they have "learnt" over the years and now believe them to be gospel.
here are some examples.

1mm-not suitable for domestic lighting anymore.
it is perfectly acceptable providing the load and distances are within limits

1.5mm-10A
some cables (mi) can take up to 23A in 1.5mm
20A is still possible with twin and earth if it is clipped direct.

 

[Phill104]

As well as the correct type of MCB, I'd ask for a replacement undamaged cover to be supplied!

Out of interest, do you have the EICR that was carried out? It might be interesting to see (you can redact the personal details incl. those of the "electrician"'s).

Not yet. That is being sent at a “later date” however long that will take

 

[westward10]

How ironic someone finds an apparent Code 2 then rectified it by leaving at least one Code 2 in itself, absolutely unbelievable.

 

[Simon47]

In the board was a 40amp mcb. This was connected with 6mm EV ultra cable.

Is this the cable ?

Rated at 58 amp

It's not as simple as that !
Since it's thermosetting, I assume table 4E2A would apply, and that does indeed say the cable is rated at 58A (6mm2 and clipped direct). But you have to read the notes, and in particular :
"1. Where it is intended to connect the cables in this table to equipment or accessories designed to operate at a temperature lower than the maximum operating temperature of the cable, the cables should be rated at the maximum operating temperature of the equipment or accessory (see Regulation 512.1.5)."
The EV point may or may not be so rated, but your CU and MCB almost certainly won't be. Therefore you need to downrate the cable - which means it'll actually only be rated the same as a thermoplastic cable to 70˚C (table 4D2A) where you'll find 6mm2 is rated to 46A.

So this week come EICR the electrician insisted on replacing the 40amp mcb with a 32 amp because the cable is only 6mm. EV sparky insists 40amp is OK. Who is right here?

Based on the above, I think the EV guy is right. But regardless, the EICR guy is wrong, absolutely no doubt just plain wrong and will now find himself paying for that.

Not impressed by the move the EICR chap did either. He didn’t have an NH compatible mcb so did some cutting to the box to make it fit. It now sits higher by 5mm than the RCBO’s and main switch and the gap below has a bit of plastic glued in.

Did he provide you with a certificate for that work ? If not demand one from him - if he is a member of one of the registration schemes (e.g. NICEIC) then I believe their rules make compliance with BS7671 mandatory. BS7671 says a certificate should be provided for any works.
Of course, to provide that he'll need to sign that the work he did complied with BS7671 - at which point he's guilty of fraud.

But regardless of whether you get a certificate from him, tell him he's coming back and a) replacing the MCB he took out, and b) replacing the front cover he vandalised to make a different one fit. As previously mentioned, BS7671 is clear that in a domestic environment, the CU must be a type approved assembly - which in practice means only using parts approved by that manufacturer for use in that board. To the best of my knowledge, no manufacturer certified a different manufacturer's breakers for "mix-n-match" in their boards.
"421.1.201 Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and ..."

You may get "some resistance" from him, but your EICR guy is 100% in the wrong on fitting a different make/type of MCB. Regardless of whether there is a reason for downsizing the rating, the only acceptable action is fitting the correct breaker for the board. If he refuses to fix that, make it clear that you'll report him to both Trading Standards and his registration scheme for dangerous work.
As to whether it should be 32A or 40A, you can reasonably expect him to give a reason - it will be interesting to see what he comes up with. Bear in mind, we haven't seen the installation so are assuming (based on the description) installation method C "clipped direct" - it is possible that a different method may apply, but I think that's unlikely from your description.

Appendix 4 Section 2.4 gives the derating factor for stranded conductors as 0.95, so the rating of 46A from table 4D2A needs reducing to 43.7A. There's no derating for an MCB (there is for a fuse), so as 43.7 is higher than 40, that circuit would appear to be correctly designed.

 

[Phill104]

Miffed?
i would be really pi55ed off about that if someone had done that to my perfectly good board in the name of electrical safety.
Unfortunately there are electricians out there that do not have a good understanding of the regulations and the thought that goes into making them.

instead of properly learning the trade and how to do it well they instead use some rule of thumb figures that they have "learnt" over the years and now believe them to be gospel.
here are some examples.

1mm-not suitable for domestic lighting anymore.
it is perfectly acceptable providing the load and distances are within limits

1.5mm-10A
some cables (mi) can take up to 23A in 1.5mm
20A is still possible with twin and earth if it is clipped direct.

Thanks James. I do have a background in electrical work. That was design and prototyping of switchgear as well as similar with battery backup systems for the rail, telecom and oil industries. All high current but often DC stuff. It has been a long time since I studied the regs (16th edition) and have never worked in the home arena having switched to working in IT in the late 90s. So while my knowledge is sound, I am very out of date and unfamiliar with how things are done in the home environment. Having said that, cable ratings were always a very important part of the design process as I am sure you know. A simple cock up in the choice of cable insulation could have cost us dearly.

 

[westward10]

Any individual who does that to a consumer unit should not be carrying out EICRs because they clearly do not understand the requirements of BS7671. I would like to meet this person.

 

[Phill104]

Is this the cable ?

It's not as simple as that !
Since it's thermosetting, I assume table 4E2A would apply, and that does indeed say the cable is rated at 58A (6mm2 and clipped direct). But you have to read the notes, and in particular :
"1. Where it is intended to connect the cables in this table to equipment or accessories designed to operate at a temperature lower than the maximum operating temperature of the cable, the cables should be rated at the maximum operating temperature of the equipment or accessory (see Regulation 512.1.5)."
The EV point may or may not be so rated, but your CU and MCB almost certainly won't be. Therefore you need to downrate the cable - which means it'll actually only be rated the same as a thermoplastic cable to 70˚C (table 4D2A) where you'll find 6mm2 is rated to 46A.

Based on the above, I think the EV guy is right. But regardless, the EICR guy is wrong, absolutely no doubt just plain wrong and will now find himself paying for that.

Did he provide you with a certificate for that work ? If not demand one from him - if he is a member of one of the registration schemes (e.g. NICEIC) then I believe their rules make compliance with BS7671 mandatory. BS7671 says a certificate should be provided for any works.
Of course, to provide that he'll need to sign that the work he did complied with BS7671 - at which point he's guilty of fraud.

But regardless of whether you get a certificate from him, tell him he's coming back and a) replacing the MCB he took out, and b) replacing the front cover he vandalised to make a different one fit. As previously mentioned, BS7671 is clear that in a domestic environment, the CU must be a type approved assembly - which in practice means only using parts approved by that manufacturer for use in that board. To the best of my knowledge, no manufacturer certified a different manufacturer's breakers for "mix-n-match" in their boards.
"421.1.201 Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and ..."

You may get "some resistance" from him, but your EICR guy is 100% in the wrong on fitting a different make/type of MCB. Regardless of whether there is a reason for downsizing the rating, the only acceptable action is fitting the correct breaker for the board. If he refuses to fix that, make it clear that you'll report him to both Trading Standards and his registration scheme for dangerous work.
As to whether it should be 32A or 40A, you can reasonably expect him to give a reason - it will be interesting to see what he comes up with. Bear in mind, we haven't seen the installation so are assuming (based on the description) installation method C "clipped direct" - it is possible that a different method may apply, but I think that's unlikely from your description.

Appendix 4 Section 2.4 gives the derating factor for stranded conductors as 0.95, so the rating of 46A from table 4D2A needs reducing to 43.7A. There's no derating for an MCB (there is for a fuse), so as 43.7 is higher than 40, that circuit would appear to be correctly designed.

Thank you for your detailed response. That will be really helpful in my complaint. Just for the record, here is a pic of the cable and how it is clipped.