Electricity supply to your garage??

[pandemonium123]

Im just about to start fitting electrics to my new build garage, and wondered what everyone else has and how it is run to your workshop/ garage??

what size swa cabe have you used?

is it running from your consumer unit with its own rcd or split off the 100amp supply before that?

is 60 amps enough

ill be running the following stuff:
6 strip lights
radio
2x3hp clark industrial compressor 30amp
180amp sip mig
40 amp plasma cutter
some cordless battery chargers

currently there is a cable and consumer unit in the garage but it is about 12mm O/D swa so i think this is only good for around 32amps with one 20 and 10
amp rcds, my main concern was putting a to big a load on the house 100amp consumer when things like dishwasher oven and the likes are all running at the same time when im in the garage

any ideas

 

[GrahamGKD]

Mate,
If you look at:

http://www.tlc-direct.co.uk/Main_Index/Cable_Index/Armoured_SWA/index.html

You should see they have a cable size calculator. The choice of cable hinges on the length of the run (there are also two types of SWA - XPLE is capable of carrying a higher current). One thing to think about is not just whether the SWA is heavy enough to carry the current but how much voltage drop you are happy to tolerate at the workshop end.

For my set up the calculations were borderline so I chose the heavier cable - 10mm (10 square mm conductor area - not cable outside diameter). It is fed from a MCB in the consumer unit (the one nearest the main switch after the 10.5KW shower) and I have the house (electricity board) earth exported to the workshop. The acceptable earthing arrangement will depend on the kind of earth you have in your house (I think there are about three different types). If I recall, earthing gets more complicated if you have any water supply in the remote building.

At the workshop end I have another consumer unit with separate mcbs for all of: a normal ring, normal lighting circuit and 16A and 30A industrial sockets.

Not sure about your concern about exceeding the house supply limit - I guess you could take out the electricity board fuse? Clearly it will depend on how much of the workshop kit you have running at one time. Maybe it would be better to limit the supply to the workshop with an mcb in the house rather that have the embarrassment of taking out the board fuse?

BTW, I'm not a qualified sparky but hopefully one will be along soon.....

Hope this helps.

Graham.

 

[Robotstar5]

my main concern was putting a to big a load on the house 100amp consumer when things like dishwasher oven and the likes are all running at the same time when im in the garage

You can split the supply before the consumer unit for a seperate (protected) feed to the garage, but you have to remember the service fuse for your property will be 80 or 100A so has to be taken into account when calculating your loadings

 

[brightspark]

garage suply

if u want a decent suply to garage as robotstar says split the suply cable between the meter and house consumer unit fit a mains double pole service conector block eg a pair of mains tails out of meter into the twin block then one set to house consumer unit and another set to a 60 amp double pole switchfuse . then run a 16mmm 3 core swa cable out to garage the 3d core being the earth. use earth lugs on glands to bond the outer sheath. if the electricity board suply the eath back at meter u can fit a 5way db in garage with a 60 amp rcd mainswitch unit with 30 ma trip and minature circuit breakers the house services should be bonded eg cas and water suply in 10.0mm earthwire and the earth to the db s from the board suply in 16.0mmm. if theres water suply in garage and its all in pvc no action required. if its in copper it must be bonded . as for elecricity boards suply its probably 80 or a 100amp just make sure u arent using it to its max with everything on at once . i shouldnt say this but if u blow it just ring them up and report no power . dont tell em the load u have on it they will fix free but if u do it again they will bill u £50.00