No
Is this bad practice?
- Thread starter xdrive
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411.3.4?
Regulation 411.3.4 requires that, within domestic (household) premises, additional protection by an RCD with a rated residual operating current not exceeding 30 mA shall be provided for AC final circuits supplying luminaires
Unless it's a new circuit, that is not relevant.
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Yes, but that's a different reg for a different reason.
Indeed - and, like 411.3.4 (and every other reg), it's not retrospective, so would not automatically apply to an existing cable (opinions seem to vary as to how much has to be done to an existing circuit to invoke 'current requirements' for the entire circuit).
Kind Regards, John
The new works needs to comply with the current regs. So there's 2 regs that it needs an rcd for, and it needs mechanical protection too. The regs don't apply retrospectively to the whole circuit, the regs apply to the new work that is being done. If the plaster/board is thick enough you can get a bit of angle iron in over the cable where it crosses the joist.
There's clearly no argument about the new work but, as I said, there appears to be some debate about the rest. Some people seem to believe that if one goes beyond some (ill-defined!) amount of addition, modification or re-purposing of an existing circuit, that one then invokes a requirement for the whole circuit to comply with current regs.
I'm not sure what you have in mind there. It might be possible with 'a bit of iron', but I'm not quite sure how one could do it with angle iron.
Kind Regards, John
My take on it is much the same as Skenks, a circuit serving lighting points in a domestic environment is required to be RCD protected, if you install a point there that wasn't there before then that needs to be on a circuit thats RCD protected. You would obviously not have to provide RCD protetcion if you were only changing the fitting, you have not created a point that did not exist before (But a small note in comments on existing box wouldn't go amiss)
If I understand you correctly, that's surely the opposite of what skenk said (about 'not retrospective'). If one "installs a point that wasn't there before", the wiring to the new point clearly has to be RCD protected, but "needs to be on a circuit thats RCD protected" seems to imply that the entire circuit (including pre-existing bits) has to be RCD protected. Is that what you meant? In this simple case, then the sensible (and probably simplest) solution would probably be to RCD protect the whole circuit - but in other situations (like adding umpteen sockets to a sockets circuit) that might not be the case.
Kind Regards, John
In practical terms, yes.
If you have added lighting points in the kithen then the lighting circuit serving these new points needs RCD protection, there is nothing telling you have to provide RCD protection to the points in the living room, dining room or garage, but by virtue of them being on the same circuit they are going to be. If however the lighting circuit branched at the MCB with the garage lights wired separate from the MCB, then I'd consider it compliant to route only the leg supplying the section of lights that included the new points through the RCD, theres probably very little reason to do this, though.
Indeed, as I said, that's almost certainly going to be the easiest way to do it, whether required by regs or not.
Again, I agree. However, I think that's where some people might disagree, particularly if the added lights were numerous and all over the place (e.g. in a new extension). By BS7671 definition, everything supplied by the one MCB would count as 'one circuit' and some (not me!) might say that if one extensively extended one of those arms (or even the one and only arm), that might invoke the requirement for 'the entire circuit' to be RCD protected.
However, as I said, it's unlikley to ever be much of an issue with lighting sockets - I think that extensive additions to, or modification of, a sockets circuit could raise more questions.
Kind Regards, John
Isn't it usually easier just to put the whole circuit on an RCD whether lights or sockets?
I'd prefer drilled holes in the joists but it's an awkward job unless the whole ceiling is being re-plastered, if it isn't it will be hard to match the Artex surface anyway and it will look pretty Sh!t
I'd prefer mechanical protection but a Drawing pin won't penetrate the entire ceiling - maybe a Safe plate would make it more acceptable to some in the absence of an RCD - whether it's deemed necessary or not. You'd have to be a complete idiot to drill into a ceiling without using a pipe/cable protector.
https://www.toolstation.com/safe-pl...m_medium=feed&utm_campaign=googleshoppingfeed
I'd prefer mechanical protection but a Drawing pin won't penetrate the entire ceiling - maybe a Safe plate would make it more acceptable to some in the absence of an RCD - whether it's deemed necessary or not. You'd have to be a complete idiot to drill into a ceiling without using a pipe/cable protector.
https://www.toolstation.com/safe-pl...m_medium=feed&utm_campaign=googleshoppingfeed
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