I'm having a summer house installed within the next 6 weeks and will need to provide power to the building (Max power consumption is 3KW). The feed needs to supply a 16A ring circuit and and a 6A lighting circuit. So I'm thinking of fitting a 2-way Garage Consumer Unit (with RCD protection) inside the summer house, fed by an armoured cable (4mm) because it's a 15M run from the house. This will connect to an exisitng spur off the downstairs ring main (32A supply from the main consumer unit). Is this sufficient for the job or are my thinking and calculations wrong?
Are you a tradesperson and able to answer this question?
Hi Rob,
you mention that you require a 16a ring and a 6a lighting circuit. If you are taking it from an existing spur you will be limited to 13 amps. In my opinion it would be far better to take the cable back to the distribution board and make the summer house board a sub main. I would also recommend protecting the sub main supply cable with an rcd/rcbo from the distribution board in the house.
I’d recommended 6mm cable or even ten mm SWA plus for all the additional cost of a 2 way consumer unit and a 4 isn’t a lot this leaves you both safe and with the possibility of adding another circuit in the future .
let an electrician sort this out. dont do this by yourself. advertise the job on my builder and see what quotes you get. thats what we are here for to make sure the install is safe to use and give what the customer wants. don't design leave it to us
Hi. This is something you dont want to attempt yourself so it's not wise to give help via this site. The work needs test certificates and building control would need to be notified. There are many variables to do what want, it needs designing correctly for its intended purpose. I suggest you get a registered Electrician to come and give you a quote to carry out the work.
