Why "No RCD protection on lighting circuit"?

[seanelectrical]

The lighting circuit is based on twin and earth 1.5mm cable with plastic switch/back boxes. I have had bulbs fail and the MCB trips.

That's what they do sometimes.

I have now terminated earth cables in single switches with choc blocks and in 2/3 gang switches I have connected the earth cables via choc block.

Is everything plastic - not metal back box or metal switch?

Does RCD protection require all earthing to be connected?

Not RCD - but of course, although you cannot connect to plastic.

Would floating earth leads in switches cause “no RCD protection on lighting circuit”?

No.

An RCD is a protection device which must be fitted to NEW wiring under certain conditions and sockets.

It is not required on a lighting circuit just for the sake of it.

Sure lighting in a bathroom must have RCD protection???

 

[Iggifer]

Sure lighting in a bathroom must have RCD protection???

Didn't see any mention of a bathroom from the OP, but yes of course lights in a bathroom must have RCD protection.

 

[EFLImpudence]

An RCD is a protection device which must be fitted to NEW wiring under certain conditions and sockets.
It is not required on a lighting circuit just for the sake of it.

Sure lighting in a bathroom must have RCD protection???

Not exactly sure what you are asking but:

All new circuits to a bathroom must have RCD protection.

 

[DixMohr]

I was also in the same confusion in which you are now. I found that if some of the lighting wiring is less than 50 mm from the depth of the wall surface or is in a bathroom then that wiring at least needs to be protected by an RCD.
The simplest way to achieve this is replace the MCB covering the circuit in question for an RCBO. Also the lighting circuit is not protected by an RCD in your CU. There is no regulatory requirement for a lighting circuit to be RCD-protected.

electronics assembly

 

[DixMohr]

I was also in the same confusion in which you are now. I found that if some of the lighting wiring is less than 50 mm from the depth of the wall surface or is in a bathroom then that wiring at least needs to be protected by an RCD.
The simplest way to achieve this is replace the MCB covering the circuit in question for an RCBO. Also the lighting circuit is not protected by an RCD in your CU. There is no regulatory requirement for a lighting circuit to be RCD-protected.

 

[Lectrician]

So this chap happily energised his circuit without any testing, and not only that, didn't connect any earths, so a fault was unlikely to even trip an MCB. Clueless to the danger he put himself and others in. Then berates the inspector that picks him up on things that clearly don't comply. He should be thanking the inspector for picking up his lack of earth continuity.

Sorry, but what a t1t.

 

[bubachuba]

just caught up with this thread in its entirety and slightly on topic... this <50mm from the surface reg is very unlikely to be met when you think about it. if its >50mm on one side, its going to be <50mm on the other side of the wall considering most (albeit, not all) walls are no more than 100mm thick!

 

[ban-all-sheds]

Most of mine are 130-150mm...

 

[bubachuba]

BAS - i was really referring to modern, stud walls.

 

[ban-all-sheds]

Ah - the Devil's work.

 

[bubachuba]

Ah - the Devil's work.

indeed!

 

[PBC_1966]

But from what I believe the LABC inspector has to follow BS7671:2001 or similar which is not the latest BS7671 edition anyway. That is what the official approved Part P document says anyway.

What the LABC inspector has to follow (or is supposed to follow) is the actual requirement of Part P of the Building Regulations which just says that installations must be reasonably safe. He doesn't have any legal remit to insist on an installation meeting all the requirements of BS7671:2008, BS7671:2001, or BS7671:anything, and as you say, the guidance (not law) in the approved document even sets out other specific ways which should be considered as being acceptable (but does not set out every way and notes in itself that there is no requirement to follow any particular recommendation contained within it).

The unconnected earths are indeed worrying, and it really isn't a good idea to fit some item so that the wiring is hidden away with the intent of going back later to finish it off, especially if you're not going to carry out any tests before hooking up the power. But as for the fuss about RCD protection, I find it laughable that anyone could seriously believe that having a few more switch drops less than 2 inches from the surface without RCD protection means, in itself, that the installation is not reasonably safe. Yet there are electricians who claim that despite having installed exactly that arrangement just a few short years ago and being perfectly happy that it was reasonably safe then. If it was reasonably safe in 2007, then it's just as safe today.

I'm also surprised nobody else has commented on the fact that the report lists every single item as "C2 - Potentially danegerous, urgent remedial attention required." No earth sleeving at a couple of sockets? Cables not clipped in the attic? Really? And this list tends to suggest, at least to the layman, surely, that this lack of earth sleeving, lack of RCD protection on the lighting circuit, and unclipped cables is on a par, risk wise, with disconnected earths and insufficient overload protection. That's ridiculous.

 

[JohnW2]

But as for the fuss about RCD protection, I find it laughable that anyone could seriously believe that having a few more switch drops less than 2 inches from the surface without RCD protection means, in itself, that the installation is not reasonably safe. Yet there are electricians who claim that despite having installed exactly that arrangement just a few short years ago and being perfectly happy that it was reasonably safe then. If it was reasonably safe in 2007, then it's just as safe today.

Quite so. However, if we are to have regulations, one cannot really blame people for feeling that one has to work to the letter of them.

It's really much the same as what you are saying, but the thing I find laughable is to 'make a fuss' about (let alone 'code' as 'potentially dangerous and needing urgent attention') a few feet of non-RCD-protected new buried cable in an installation in which 95% of the buried cables are (without 'fuss') not RCD protected. Similarly with feeling the need to use an RCD socket for an additional one on a circuit which still has maybe a dozen or more non-RCD-protected sockets.

Kind Regards, John

 

[PBC_1966]

It's really much the same as what you are saying, but the thing I find laughable is to 'make a fuss' about (let alone 'code' as 'potentially dangerous and needing urgent attention') a few feet of non-RCD-protected new buried cable in an installation in which 95% of the buried cables are (without 'fuss') not RCD protected. Similarly with feeling the need to use an RCD socket for an additional one on a circuit which still has maybe a dozen or more non-RCD-protected sockets.

I agree entirely on both counts. Sometimes I wish the U.K. electrical trade with its BS7671-driven letter-of-the-regulations mentality would actually take a good dose of pragmatism when it comes to these things.

The most extreme example is probably those who seem to think the world might come to an end, metaphorically, of course, if somebody uses a few feet of red/black cable now to add a socket to an installation which is already entirely red/black and has no brown/blue anywhere.

 

[ban-all-sheds]

OK - some questions therefore for JW2 & PBC:

How long after a change in the regulations should we have to wait before expecting people to comply with them?

Unearthed lighting circuits used to be regarded as reasonably safe - would you regard installing a new one as OK? If not, how long ago do you think they stopped being reasonably safe?

Same two questions for unshuttered sockets and using water pipes as earth, please.