single FCU for double socket?

[Darren Cooper]

Hi, I have a 13A FCU which has a single socket for the dishwasher. I want to change this to a double socket for the washing machine and tumble dryer, I assume I need to change the FCU to a 20A switch, is this correct and OK part P wise? TIA, Darren

[John Rumm]

You neglect to mention what powers this FCU... i.e. it is on a ring final circuit, or is it a spur from one, or on its own radial. What size cable feeds it, and what protection device (rating and type) does it have in the CU?

Possibly, what type of cable connects the FCU to the socket?

If it is in a kitchen then no.

[Christian McArdle]

I would say no. Whilst a run of 2.5mm cable is normally fine for a double socket at 32A protection, this is assuming that the socket has no particular likelihood of overloading. If you are intending to run the dishwasher, tumble dryer and washing machine off it (presumably using an adaptor), you can make no such assumption and should expect loadings well in excess of

20A, making a double socket unsuitable.

The very least you should do is provide single sockets actually on the ring (or fed via DP switches/FCUs on the ring). Personally, I think that kitchen/utility rooms should be designed with one or more separate circuits for laundry appliances, due to the likelihood of sustained point loads that rings aren't designed to cater for.

Christian.