Replacing a VOELCD ?

[JohnW2]

From what the Op says this device could well be the DNOs, so what kind of electrician would change it anyway, possibly breaking seals to do so? Op your first port of call must be the DNO to change it, it should not cost you anything!

If the DNO change it, what would they replace it with - a 100mA RCD? (which obviously would not provide adequate shock potection to the OP's installation). Given what we've been told about the load side of the VOELCB being split to supply two CUs, might the DNO be persuaded to replace the VOELCB with two 30mA RCDs for him, one to feed each CU?

Kind Regards, John

 

[RF Lighting]

If this was consumers equipment, I'd issue a minor works covering the replacement of the RCD only.

The installation is not compliant with the current edition of BS7671, but it is not in a dangerous condition.

Much the same as I'd replace a damaged socket front supplied from an old BS3036 fuse with no RCD.

 

[JohnW2]

If this was consumers equipment, I'd issue a minor works covering the replacement of the RCD only. The installation is not compliant with the current edition of BS7671, but it is not in a dangerous condition. Much the same as I'd replace a damaged socket front supplied from an old BS3036 fuse with no RCD.

That's what I would have expected. Do you therefore take my view that the BS7671-compliance statement you signed on the MWC relates to the actual work you had undertaken, not to whether whatever you'd replaced was compliant under current regs?

Kind Regards, John

 

[westie101]

If the DNO change it, what would they replace it with - a 100mA RCD? (which obviously would not provide adequate shock potection to the OP's installation). Given what we've been told about the load side of the VOELCB being split to supply two CUs, might the DNO be persuaded to replace the VOELCB with two 30mA RCDs for him, one to feed each CU?

We install 30mA replacements if needed (as a lot of customers have rewired & fitted RCD CUs)

If it were me I would perhaps have an isolator fitted and co-ordinate this with the customer fitting his own RCDs.

But that is me, what his DNO and their staff would do I have no idea!

 

[JohnW2]

We install 30mA replacements if needed (as a lot of customers have rewired & fitted RCD CUs)

Do I take it that if the customer had a (just) dual-RCD CU, you'd simply remove the VOELCB and not replace it with an RCD? What if it were a 'high integrity' CU (2 RCDs plus some non-RCD circuits) - would you then install a Type S 100mA RCD in place of the VOELCB,or what?

Kind Regards, John

 

[westie101]

We would not leave it any less safe for EL protection than we found it! In a lot of cases the bonding is updated as well so, in consultation with the customer & their electrician, we may make an earth available.

There is no on size fits all answer, much as some prefer one, we would do what is required within our remit.

In most cases we are contacted by an electrical contractor who is doing a rewire or modification anyway. I think that, locally, we have only attended one failed unit in the last couple of years!

 

[JohnW2]

We would not leave it any less safe for EL protection than we found it!

I'm sure you wouldn't, and wasn't suggesting that you ever would.

What I was wondering was whether you would ever put a non-time-delayed RCD (whether 30mA or 100ma) upstream of a CU with two RCDs (maybe because there were also non-RCD circuits) - since, if you did that, you could well undermine the BS7671 requirement (within the customer's installation) for 'separation of circuits'.

Kind Regards, John

 

[westie101]

since, if you did that, you could well undermine the BS7671 requirement (within the customer's installation) for 'separation of circuits'.

Given that we already do in all single phase supplied premises with only one cut-out fuse it would not be an issue if the device is ours!

 

[JohnW2]

since, if you did that, you could well undermine the BS7671 requirement (within the customer's installation) for 'separation of circuits'.

Given that we already do in all single phase supplied premises with only one cut-out fuse it would not be an issue if the device is ours!

It's rather different. Having a single cutout fuse does not prevent a customer's installation complying with BS7671 by 'dividing circuits' between two RCDs so that L-E or L-N fault in one final circuit would not take out all of the customer's circuits. However, if a DNO stuck a non-time-delayed RCD upstream of the customer's equipment, that would effectively prevent that installation ever being able to comply with BS7671 in that respect.

Kind Regards, John

 

[ban-all-sheds]

Interesting question. (S)he obviously could not sign a document saying that the installation was compliant with current BS7671, but I'm not sure that they would have to - would they not be declaring that, to the best of their knowledge and belief, the work for which they had been responsible was compliant with BS7671?

The implication of what you're suggesting is that it is never possible for an electrician to, say, replace a defective item in an installation (say the RCD in a single-RCD CU) if the initial installation of that item would not be compliant with current regs. Is that what you believe?

Good question.

Could the same position be taken with the replacement of an entire CU?

 

[ban-all-sheds]

If this was consumers equipment, I'd issue a minor works covering the replacement of the RCD only.

The installation is not compliant with the current edition of BS7671, but it is not in a dangerous condition.

Much the same as I'd replace a damaged socket front supplied from an old BS3036 fuse with no RCD.

What about replacing a damaged CU?

What about, having been asked to fix a lighting problem, replacing an existing metal switch on a circuit with no cpc and no RCD?

What about replacing a section of damaged cable buried in a wall that was in the wrong place and/or had no RCD protection? Would you re-bury it because that's how it was?

 

[JohnW2]

Interesting question. ... The implication of what you're suggesting is that it is never possible for an electrician to, say, replace a defective item in an installation (say the RCD in a single-RCD CU) if the initial installation of that item would not be compliant with current regs. Is that what you believe?

Good question. Could the same position be taken with the replacement of an entire CU?

As we've both said, these are interesting questions. Given the lack of a general requirement to upgrade an existing installation to current standards, I think one could well try arguing that replacing a (e.g. damaged) CU with one which essentially the same as the (compliant when installed) original was allowable, even if was not compliant with current regs (e.g. either 0 or 1 RCDs).

There do, however, clearly have to be some common-sense limits. For example, I think we could agree that it would not be acceptable (today) to replace a VOELCB with a new one (even if one could find a new one).

... so, I'm not sure where the lines get drawn. Electricians must have to make these decisions every day, so it will be interesting to hear their views.

Another issue, of course, is that of what the customer will allow to be done, since they clearly can't be forced to accept, and pay for, any particular work. So what if the customer wants certain 'repair' work done, but isn't prepared to allow any associated work (e.g. addition of RCD protection) that would be required for that work to be compliant?

Kind Regards, John

 

[ban-all-sheds]

So what if the customer wants certain 'repair' work done, but isn't prepared to allow any associated work (e.g. addition of RCD protection) that would be required for that work to be compliant?

What if he wants a new socket added but will not pay for an RCD one or for RCD protection to be added at source?

What if he wants something which needs new cable, won't countenance surface mounting it but won't pay for RCD protection?

 

[JohnW2]

So what if the customer wants certain 'repair' work done, but isn't prepared to allow any associated work (e.g. addition of RCD protection) that would be required for that work to be compliant?

What if he wants a new socket added but will not pay for an RCD one or for RCD protection to be added at source?
What if he wants something which needs new cable, won't countenance surface mounting it but won't pay for RCD protection?

Indeed - those are two examples of exactly what I was asking you, but you seem to be trying to bounce the question back to me

Kind Regards, John

 

[ban-all-sheds]

Not really bouncing it back, just trying to highlight that once you admit shades of grey you find far more of them.

Another issue, of course, is that of what the customer will allow to be done, since they clearly can't be forced to accept, and pay for, any particular work.

Indeed not, but they can be denied work if they will not accept any required consequentials.