Exterior light with limited options

Gavin Cameron · Jan 17, 2019

Thanks for the add. wanting to add an outside light to a house but very limited access and they have only just done up the interior with new carpets etc so don't want to make a huge mess. the only supply near to the location is a spur off the downstairs socket circuit going to a SFCU for a boiler. anything I can do with this supply to get a light up for them? Thanks for any advice offered.

telectrix · Jan 17, 2019

come off the incomer of the boiler SFCU into a 5A SFCU for light. this extra SFCU can be used as a switch for the light, or you can fit an additional switch. also a PIR light is an option.

DPG · Jan 17, 2019

telectrix said:
come off the incomer of the boiler SFCU into a 5A SFCU for light. this extra SFCU can be used as a switch for the light, or you can fit an additional switch. also a PIR light is an option.

Sounds like the SFCU is already a spur from the ring though.

Blissof89 · Jan 17, 2019

As long as the spur from the ring is protected by fcu w/13a fuse at its origin you can feed more points from it.

I'd suggest fitting a fcu at the socket the spur comes from then you can do what was suggested above.

Maybe check Zs at the boiler spur to make sure you are not going to fall outside of max values, although this shouldn't be a problem if existing install is of good quality.

Deleted member 9648 · Jan 17, 2019

Whilst I would agree the above is technically correct, if the spur is definitely only serving the boiler FCU with likely a 3a fuse, then adding a second FCU for a light with a 3a fuse is not going to overload the spur cable. In practice this is no different to a double socket on a spur with two 3a appliances plugged in. That the spur is correctly wired directly off a ring circuit would need to be verified though.

Nebu1a · Jan 17, 2019

You can get some good battery operated external led lights these days, with integral PIR and a key fob for manual override. Depends upon how much light they need I guess.