Spurring off a spur

[Cremeegg]

Anyone care to comment on spurring off a spur. Before I get flamed on here it’s as a result of an interesting discussion with a pretty switched on although somewhat weird customer who for some reason prefers switched FCU’s with neons to ordinary plateswitches. The house is littered with them – hardly a plateswitch in sight.

One set of existing cabinet lights is spurred off the 32A ring main; they are switched via a FCU fused down to 3A. No problem – don’t like FCU’s as switches myself but what the hell. Customer wants another set of lights for another display cabinet on the other side of the room and is suggesting the FCU to stay as main isolator for lights fused at 5A but on the load side of this to wire in two more FCU’s to act as switches for the two sets of cabinet lights to display his model soldiers.

I can see his point that each cabinet lighting circuit is fused down from the ring and both lighting circuits are controlled by a fused down FCU. So the main FCU at worst case can only draw 13A and each secondary FCU could only draw at a max case 13A assuming the other was off. If they both tried to draw their 13A then they would be protected by the main FCU at 13A. In fact he should continue to fuse down to 3A.

I’m going to refuse to do it as I’m getting very bad vibes from this guy already but can anyone point me to a specific Reg in BS7671 or elsewhere that says he can’t run a switched fused spur off a switched fused spur.

Time for football and then the rugby now.

 

[plugwash]

I can't see any reason not to run a switched fused spur off a switched fused spur though it does sound like overkill.

 

[equitum]

IMO there is nothing in the regs to say you can't take a spur from a fused spur. In fact the opposite is true, its a requirement that more than one spur from the ring final needs to be fused. I would prefer the lights to be switched from the lighting circuit, but don't understand why you are reluctant to do the work, as its perfectly safe and compliant to do this.

 

[Cremeegg]

Thanks - didnt think I was missing anything but always best to check. As for not doing it - years of experience dealing with people like this just gets the old gut feeling going especially when customer is already "discussing" disturbance and almost arguing the toss on any suggestion. Makes me think it'll just be a pain and time to price very high.