Is spur to garage up to regulations? Ask questions and find answers to many subjects relating to electrics and electrical work

[Luke4874]

Hi, we have power to our garage which seems to be an unfused spur off our groundfloor ring. We have 1 light ;
(protected by a 5a FCU) and 1 double socket running on the spur.

I want to add another socket but am aware of the rules for a spur to only feed a double socket at most.

I have 2 questions:

1) When the house was handed over to us 6 years ago) was it to regs based on having a double socket and a light switch which could (in theory) pull 18a? I'm guessing diversity was included.

2) Could I apply diversity to the spur and add a permanent 13a fcu for a dryer which will only ever run overnight (so nothing else on at the same time). I could add a 13a fcu before the socket to protect it in the same way?

Any advice appreciated

[Mr White]

There is more to it, than you assume.
What are the earthing arrangements, what is size of the cable from house to garage, distance of actual cable run.
As it stands it does not sound good, you would be better off getting an electrician to establish the facts.

[ericmark]

A ring final relies on a low load near the ends so as not to overload one leg, so the rules say any fixed equipment should not have a load over 2 kW, a supply to a outbuilding from a ring final if taken near centre using a fused connection unit is unlikely to cause an overload.

However near the ends it could even with a 13 amp fuse.

It is already breaking the rules by having both lights and socket on an unfused spur, so clearly can't add more to it.

However if all goes through a 13 amp fuse in a FCU the max load is limited, so risk is low, but depends where in the ring it is taped in.

I know we can break the rules for years and get away with it, but really not worth taking the chance.