Srur it?

[growler]

Another trivial topic but here goes... iv been asked to install a security light in a back garden, switch will be located by back door above worktop. there is already a spur (kitchen ring) next to where the switch will go. Just pondering whether to take easy option and spur of ring or take a feed from kitchen light and keep lights seperate? probably a no brainer!

 

[telectrix]

can't see a problem with fitting a switched FCU (3A) from the rfc.

 

[Octopus]

Spur from a spur?

 

[telectrix]

existing socket is allowed as an unfused spur. a fused spur should by rights be fitted before that socket and then a 3A FCU from that. however, whilst unconventional, i can't see a problem with fitting a 3A FCU after the unfused spur socket.

 

[Octopus]

existing socket is allowed as an unfused spur. a fused spur should by rights be fitted before that socket and then a 3A FCU from that. however, whilst unconventional, i can't see a problem with fitting a 3A FCU after the unfused spur socket.

Tel, I quite agree with you but the books and guidance say otherwise! lol

 

[telectrix]

key word is guidance. such an arrangement would be just as safe as if the guidance ( BS7671 ) was followed to the letter and so i stand by it. some may disagree. opinions welcome.

 

[GLENNSPARK]

what would be the problem Tel?....still fused down innit......

 

[Octopus]

what would be the problem Tel?....still fused down innit......

spur from a spur!

 

[telectrix]

my argument exactly. it's basically drawing an extra max. of 3A over and above the assumed 20A load of the spurred socket, i.e 23A max. on 2.5mm cable rated at 27A ( ref. method C).

 

[SPARTYKUS]

spur from a spur!

Murdoch

I don't think it means that kind of spur, I thought it referred to a socket outlet on a RFC. Clearly a spur off a spur off a spur is ok on a radial.

However in this case i would sleep soundly, but can also see the point- a spurred DG socket at full load on a single piece of 2.5 is ... At full tilt so no room for an extra bit on the end......would be ok though if the spurred DG socket was supplied by ref method 'free air' (30A). )

 

[needasparks]

I'm with Tel on this but if you have an issue with it fuse the socket down with a sfc of its own so it cant pull more than 13amps if your worried.
We are talking a 100w light yes, with a fault current max of 3amps.

 

[telectrix]

security light generally will be 400 or 500 watt, still only a couple of amps , though.

 

[Octopus]

I'm only playing devils advocate - you know, its a no, no to do a spur off a spur whilst common sense clearly sees and calculates that the load on the spur will be well under the capacity of the cable!!

 

[telectrix]

its a no, no to do a spur off a spur

why? it's a no.no to add an unfused spur off a spur. where's the reg. says you can't take a fused spur off an unfused spur

 

[growler]

to clarify, the spur is on the ring and not a spur off the ring. these security lights require a permanent feed dont they? so prob will have to come of the lights anywho! cheers