cable selection for garage

[neilyboy1961]

garage has an old T&E spur from the house I intend running an SWA cable to the garage,what size do I need

garage will have 1 circuit (ring main ) consisiting of 6 sockets, 6 100w lights
and quite possibly a small welder which I think can be run off of a 13a plug


anyone help

cheers

 

[bongos]

You don't mention the length of the cable run. Have a look here at calculating the relevant size.

Have you any unprotected spare ways on your house CU? Ideally you would run the relevant size SWA from your CU to the garage, where you would have a smaller CU with a circuit for lights, sockets and a seperate one for a welder if you can't plug it in. This may be a good idea anyway if there is a large inrush current from the welder. The sockets must be RCD protected and the other circuits may have to also, depending on your cable installation method.

However, there are also other things to consider, such as earthing types and whether you have any extraenous conductive parts in the garage. Is the garage connected to the house?

Still, at least no Part P to worry about...

 

[ban-all-sheds]

Have a look here at calculating the relevant size.

When you use that calculator you must:

1) Tell it you'll be using 2-core, even if it will be 3-core

2) Tell it you'll be using PVC cable, even if it will be XLPE

or it'll give you an incorrect answer.

 

[Steve]

6 100w lights

What on earth for?

 

[neilyboy1961]

6 100w lights

What on earth for?

probably not, 6 lights just overcompensating for cable size,I've been off the tools for over 25 years and want to get the right cable in

 

[bongos]

probably not, 6 lights just overcompensating for cable size,I've been off the tools for over 25 years and want to get the right cable in

You'd probably still end up using a 6A MCB with 1mm² or 1.5mm² on the lighting circuit usually - unless you had some huge lighting demands in the garage.