Garage/workshop

[onewoz]

Hello
I am installing power in my garage/Workshop mainly workshop
i am considering fitting a small consumer unit (apparently made for a garage)IP55 VCGKIT comprising 40A 30mA RCD and 1 x 6A, 1 x 16A Type B MCB RCD providing earth leakage protection. MCBs provide individual circuit protection. BS EN 60439-3.(Screwfix)
Having 6 double sockets
Do i need to up the 16a to a 32a (and can i in this box?) for a ring main? what cable do i need from main consumer box to the garage distance between 30 foot to 40 foot. whats the mcb amp have to be on the main unit Got a lot of cable and fittings from a builder friend just need a unit so i can work out if possible to do it myself or hire someone
My main unit in the house is rcd protected
thanks for your time

Warren

 

[foulplay]

Hi,

I'm doing the same job, feed the garage from your main consumer unit with 6sq mm cable, if your putting a ring in the garage, change the local mcb to 32A, you do not need RCD protection if the main consumer unit already has it.

regards

foulplay

 

[dingbat]

Hello
I am installing power in my garage/Workshop mainly workshop
i am considering fitting a small consumer unit (apparently made for a garage)IP55 VCGKIT comprising 40A 30mA RCD and 1 x 6A, 1 x 16A Type B MCB RCD providing earth leakage protection. MCBs provide individual circuit protection. BS EN 60439-3.(Screwfix)

You'll have fun wiring up that Screwfix unit - hope you have tiny fingers! And then you'll have even more fun getting the cover to fit. The reason for supplying a 16A mcb with that is that most people will install a radial socket circuit in 2.5 sq mm T & E. As foulplay has said you can only change this for a 32A if you install a proper ring circuit.

If any part of the supply cable run is outside you should use SWA (steel wire armoured) cable (suitably buried/protected) and you'll have yet more fun trying to properly terminate that in the Screwfix unit, especially if you use 6 sq mm and a 25mm gland. If you really do want to use this consumer unit I'd advise dismantling the whole thing, including the DIN rail, cut out your cable entries, then mount it, feed in the cables and reassemble the unit as you go.

But if you haven't bought the consumer unit yet do yourself a big favour and buy instead a small metalclad c/u from a wholesaler and use metalclad socket outlets as well. It will be much easier to work with, look much better and be far more robust in use.

 

[plugwash]

yeah the other reason for getting a metal cu is you can terminate the incomeing swa to it directly

 

[unphased_spark]

onewoz

The fact you have a run from your main CU to your garage/workshop
of only 30-40 ft I would say 4mm sq 3 core SWA would suffice. Your main CU has RCD protection which in the event of you developing an earth fault leakage in your garage/workshop will cause those circuits protected by the RCD to also disconnect. RCD protection in the CU you intend to install in the garage/workshop would prevent this scenario form occurring. Remember the RCD from the main CU will protect the cable
supplying your garage/workshop...... the RCD incorporated in the garage/workshop CU will protect those circuits within.
Do you have experience of working with SWA cable ? Incorrectly terminated cables will inhibit the earth fault protection provided..... if in doubt call in a professional.

 

[stueyB]

Hi
I'm doing the same job at the moment, so this is great! Could someone answer the bit about the rating for the mcb on the main cu?
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