Wiring regs sanity check

Was talking to an electrician about fitting some new sockets in the (built-in) garage near the consumer unit (adding more to some existing sockets). In the course of the conversation he said 'and you'll need to upgrade the consumer unit to add RCDs on your lighting circuits to bring it up to standard if you sell the house'. The consumer unit was fitted (by him) about 6 years ago to replace a 1970s installation. It's a bog standard no-brand consumer unit: can't remember if there are any spare slots on it or not. The lighting circuits are currently on MCBs.

Is this right? I thought that any installation, as long as it's up to code at the time it was fitted, is permissible as far as regs is concerned. So that 1920s lead sheathed wiring is permissible (though not a great idea), as long as it was installed in the 1920s and not more recently.

After various changes of plan it appears that some work will be required to fit extra garage lights and alter the switching arrangements. Again these are pre-existing lighting circuits. Does that alter the need or lack thereof to install RCDs? The charge, in addition to the lighting work, would be 4x £35.

Thanks Theo

Reply to
Theo Markettos
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Wiring doesnt need to be anywhere near regs to sell a house. If you wire it to 1970s regs today and sell tomorrow, thats ok as far as selling goes. If you push it to the extreme you could wind up in trouble for endangering so meone's life, so no razor blade hot water heaters.

He just wants paying - what's new.

NT

Reply to
meow2222

Complete bollocks - a buyer's surveyor will just say "It's not up to current standards", and everybody even remotely sensible will go "Yeh, and?".

Reply to
Adrian

Unless we can see it, and know exactly what was said, we cannot judge whether RCDs are needed or not. To sell a house, you do not need to have RCD protection. For him to give you an Installation Certificate, you may need RCD protection on new parts of the install. For all new socket outlets, you do need RCD protection. For existing, untouched, circuits, there is no need to upgrade to RCD protection. If he is using the current non-RCD circuit to supply the new lighting, then the new parts of the install may need RCD protection.

All depends. Surface mount, not in a special location then it may be possible to omit RCD protection.

But , to supply, install, and test 4 RCBOs (which I assume is what is being fitted), then £35 each is not bad, and will give you a far better safety margin than the current CB protection.

Reply to
A.Lee

In our case "needs urgent attention" were his words.

Rubber wiring in thatched roof space!

It was the first job once we bought it.

Andy

Reply to
Vir Campestris

In our case, the surveyor said he knew nothing about electricity and suggested we had a separate eelctrical survey done. I said I'd do it myself.

Reply to
charles

The argument goes that on a lighting circuit it's more risky to have it go in the middle of the night, when you trip over something in the dark and break your leg trying to reset the RCD, than it is with an earth fault on overhead lights.

The two circuits in question are all overhead lights: one upstairs, one downstairs. A smattering of downlighters, the rest lampshades. A couple of extractor fans. That's it. None of them are lower than 7' from the floor. The garage work is simply to more around some existing fittings and change the switching arrangements.

Theo

Reply to
Theo Markettos

No.

That's basically correct.

There are some deficiencies that would need to be corrected at the time any other alteration were made (like lack of main EQ bonding), but no general requirement to bring old installs up to scratch - and certainly not on selling.

That's a slightly different situation. If you need to do work on a lighting circuit, then the new work will need to be to modern standards. So if that means that a concealed cable run is required that has no earthed mechanical protection, and is buried less than 50mm from the surface, that would require RCD protection (and hence the rest of the circuit would end up with it into the bargain).

Reply to
John Rumm

Does the CU he fitted 6 years ago have an RCD/RCBO for the soocket?

Reply to
ARW

I tried to borrow against my house about 6 months ago, Lloyds had agreed the loan subject to survey but after the surveyors report wanted the electrics inspected and reported on.

There are numerous areas where regs aren't met so I took out a couple of personal loans instead, just a warning that while a prospective buyer might not care their lender might have different ideas. The banks are getting really fussy when it comes to lending money.

Reply to
R D S

Yes. Everything is RCDed except for lighting (I think).

Theo

Reply to
Theo Markettos

Thanks, thought there was something fishy going on.

Yes, I agree that work on the circuit may change its status. Though the 'and you'll need...' conversation happened long before lighting changes were even imagined.

I hadn't thought about the buried cable issue, that's a good point. The risks of putting a nail through a buried cable being more than accidentally contacting wires in the ceiling. And I suppose the risk of putting your hand up a live light fitting when changing a bulb.

Theo

Reply to
Theo Markettos

So would you mind me asking to dig deeper into this before you part with the £140 (should you go ahead with it)? I do not believe that it would be money badly spent and the electrician is certainly not making a lot on the parts but I believe with a little thought, you can for about the same cost (1), be able to slightly improve on the the job .

My guess is you have what is called a 16th edition CU. This would typically have all the socket MCBs sharing one RCD and the lighting circuits,cooker and immersion etc on non RCD circuits. It would seem that your electrician is intending to replace the 4 MCBs on the non RCD side with RCBOs. That if fine but I believe that would be better if at least one of the socket circuits (the kitchen one if you have a dedicated kitchen circuit) was moved to a 32A RCBO and one of the lighting circuits moved to the shared RCD along with the rest of the sockets. The theory being that just one fault on any of the socket circuits could ATM kill all the socket circuits by tripping the RCD. Moving one socket circuit to a RCBO would stop that happening.

(1) It would cost about £3 more as there would be the extra cost of a new MCB. (2) If all your socket circuits are already on RCBOs then your electrician has certainly taken care of you in the past.

Cheers. And feel free to ask anymore questions.

Reply to
ARW

Thanks, that's some interesting insights. I'm a few hundred miles away from the installation at present, so I can't see exactly what is fitted. I'll see if I can find out.

I don't disagree about having the job done if work needs doing to the CU anyway, and the parts cost isn't really a big deal, it was the issue of him pushing CU upgrades when there was no other work in prospect that started ringing alarm bells.

That sounds about right from the timing. I'm probably conflating RCDs and RCBOs in my description.

That sounds plausible from my memory of the layout of the CU.

There's two lighting circuits (upstairs and downstairs) and two socket circuits likewise. Plus associated others (cooker, immersion, doorbell (?).) I can't be sure what's an RCD and what's MCB without looking at it.

Stupid question: why not just put all circuits on their own RCBOs and have done with it? Is it just cost, or is there another reason?

The lighting-on-RCD issue is a pain, but there will probably be new shallow-buried cabling so it would need doing in any case.

Thanks Theo

Reply to
Theo Markettos

Mainly just cost, although RCBOs are very much cheaper than they used to be now. There was also the difficulty of sourcing single module wide ones - which did not used to be available for all CU brands. That meant needing double the width of CU in times gone by.

There are some circuits for which there is no safety advantage in having a RCD (other than for protection of the cable run) and where there may be a nuisance trip disadvantage - e.g. immersion or cooker circuits. There may also be cases where you specifically want to defer the RCD protection to later in the system - say with sub-mains feeding an outbuilding.

There is no real nuisance trip risk on a single lighting circuit, so making those RCBO is probably the best way of adding RCD protection for the cable runs.

Reply to
John Rumm

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