garage wiring alterations

[andy_h]

Hi,

I've bought a new build house and it has a detached garage.

There is a single breaker on the house consumer unit for the garage which feeds a cable into the garage. This cable runs underground and comes up into a switch (inside the garage at the front) that seems to shut off all electrics, then runs via 2.5mm twin and earth to the back door where there is a switch that operates a single light . From this switch runs cable two more cables - one to a double socket and one to the actual light. (the switch seems to be doubling as a junction box)

Ideally, I'd like to put in another light at the front of the garage and a second double socket.

Is it OK/legal to cut the 2.5mm coming from the first switch (and going to the second switch) in order to do this, and could I do this via a second socket or switch - i.e cut the 2.5mm, wire both ends into the socket - and then another wire going to a second switch to a second light bulb? Or cut and put another switch (similar to existing light switch) and use this as a junction?

please see rather attached poor diagrams(I'm no artist!!)

 

[Spoon]

Welcome to the forum mate.

I presume the cable that supplies your garage is wired to the house CU. What size breaker is it wired to?
Does your house CU have RCD protection?
What is the earthing arrangement for the incoming supply to your house?
I don't like the wiring inside the garage. Can you take some pics of your house CU and wiring inside the garage and post them up please.

 

[Pete999]

Welcome to the forum mate.

I presume the cable that supplies your garage is wired to the house CU. What size breaker is it wired to?
Does your house CU have RCD protection?
What is the earthing arrangement for the incoming supply to your house?
I don't like the wiring inside the garage. Can you take some pics of your house CU and wiring inside the garage and post them up please.

If his gaff isn't that far from me I will go and have a butchers, PMd Andy for his location.

 

[Strima]

Photos are worth a thousand words!!!

 

[Gavin John Hyde]

My instinct looking at them pictures is it needs a bit of tweaking, the first switch as the op describes it I would change to a small cu - it would make things easier for him and others to understand rather than having it all off one circuit. and then run separate circuits from this new cu for the lights and sockets, this new small Cu being fed from the breaker in the house (assuming its got capacity and the cable is up to the job). We can then look at the earthing for the house and garage.

 

[davesparks]

Does the switch which operates the light incorporate a fuse by any chance?

 

[telectrix]

Does the switch which operates the light incorporate a fuse by any chance?

i was just thinking . is it a FCU. as it's a new build, the feed is probably 2.5mm T/E . done as cheaply as possible.

 

[Spoon]

I'll just wait for the OP to post some pics up. Then we should get more of an idea of whats going on.

 

[Baker1988]

I have seen this set up quite alot in the local housing association jobs. 2.5 t+e from 16A breaker to the supply side of the fused spur then from there down to a socket. Then 1.5 t+e from the load side of the fused spur to a pendant and a 5A fuse fitted in the fused spur all usually in conduit aswell.

Cheap way to do it but it is ok as far as i can tell.

 

[rolyberkin]

Same as standard new build around here, 16amp MCB, fed 2.5mm to the garage and then switched fused spurs to the lighting, conduit would be a luxury in the very expensive houses around here, most seem to be clipped direct!