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One light or ten lights, makes no difference. From what the OP has later stated though I don't believe the assessor was actually referencing the Reg in question.
Discuss Does this setup contravene any regs or is it ok? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net
Well to connect two final circuits to a single OCPD would contravene Reg 314.4.Some people’s arguement is that to connect two final circuits to the same MCB is a contravention to Reg 314.4.
I think that is not the intention of that reg.
Well to connect two final circuits to a single OCPD would contravene Reg 314.4.
However it becomes a contradiction in terms, because by doing so the two circuits become one circuit as per the definition of a circuit.
It makes reference to final circuits, to distinguish them from distribution circuits which don’t need to be connected to a separate way in a DB.But the Reg quotes final circuit and not circuit so there must be difference as both are listed in the Definitions.
It could argued that by having the two parts of the circuit so far apart, a fault affecting one part of the circuit so remote from the other might increase danger or inconvenience?
Not sure that having the two parts so far apart will facilitate safe inspection, testing and maintenance.
The light in the loft stops working, you change the lamp, check out all the wiring in the loft, only to find it’s due to a dodgy bulb in the lobby.
Whose decision was it to opt for the cheaper dual RCD configuration?
If it was the client’s, then they can hardly complain about lack of spare ways when 4 ways are being taken up by the RCDs.
mmmm, let me think about that, no. the regulations are guide ,not the f88king holly bible .I like an assessor who knows his stuff
I don't know why you didn't rewire it to the lobby lighting circuit unless impractical. Shouldn't be the need to double up to give spare ways poor design.
I imagine he would have conniptions if he (assessor) saw some of the multi light circuits and RFC with comms sockets connected at MCB that I regularly see then. I can't see why the loft light was not put up on the upstairs lighting in the first place. Someone wasn't thinking, one light on a 6a MCB could be argued to be not taking account of the sections referred to in 314.x.x i.e. OCPD. I can't see any of the stipulations from i-iv have been breached though. But it is very on the "raggedy edge" arguing the point. So the assessor could be asked what he makes of OCPD for one LED light (4-7w) 7/230 =0.03 A, does that make sense?
Don't you need to leave a certain percentage of spare ways for future use?I’ve just done a large job where I fitted a double stack board (23 ways) and by the time I’d finished we only had two spare ways left in the board. So I thought that I’d free up one more by moving the lighting circuit for the loft on to the lobby lighting circuit at the CCU so both circuits are now on the one 6A MCB. Other than that they are totally separate. They also only contain one light for the loft and two lights for the lobby (all LED’s)
To me this is no different from taking the supply from the last lobby light to the loft and actually might make it easier to find a fault if you could separate it at the board rather than mess about behind down lights.
All was good until I decided to use this job for my Stroma visit.....
I was told that in no way can I do this and I need to correct it or it will go down as a non conformity. After arguing the point for 10 minuets I gave in and put the other MCB in and moved the loft light on to its own circuit and all was peaceful again.
Who’s right here?
How then do you know which cable is for which circuit?So how is this any different from say connecting a spur to a ring final from the MCB? Or installing say some hardwired smokes and taking a supply cable from a lighting MCB?
You're not wrong, the assessor is just being a super picky d1ck!
One, two, three, four cables leaving an MCB... it's not the cables that define what a particular circuit is, it's the MCB labelling. If it says Lobby and Attic Lighting, and it has one cable going up to the attic and one to the lobby, then whats the problem?
How would you record the Zs... you'd do what you do for any other circuit... test at each point and record the highest value.
Reply to Does this setup contravene any regs or is it ok? in the Electrical Wiring, Theories and Regulations area at ElectriciansForums.net