Spur off a spur question

[curium]

I have a switched fused connection unit with a spur running off it to supply the washing machine in my kitchen. The machine is then hardwired into the wall plate supplied by the fused switch.

I'm now fitting a dishwasher as a new kitchen is being fitted.

The fitter says he'll need to install another switched fused connection unit for the dishwasher.

I asked can he not just use the power point that the washing machine is connected to. He says he can't because you can't have a spur off a spur.

I've looked around and I'm a bit confused as apparently I could convert that spur into a double socket. Is this correct? Could this double socket (a spur off the ring which is controlled by a switched fused connection unit on the wall above the worktop) safely feed a washing machine and a dishwasher running at the same time? If necessary, due to clearance issues, is there any reason why both appliances couldn't be hardwired in at this point instead of plugged into the double socket?

Thanks for any advice.

 

[ricicle]

If you power a washing machine and dishwasher through a single FCU you will sooner or later end up blowing the fuse when they are both calling for heat. And certain double sockets are not rated for loads of >13A (although the FCU would prevent this anyway)

 

[RF Lighting]

You kitchen fitter is right.

A 13A FCU can NOT supply a 26A load such as a washing machine and a tumble dryer. This is due to the laws of physics.

A double socket should not be used to supply two heavy loads such as a washing machine and a tumble dryer otherwise this has a habit of happening.

 

[ricicle]

Rob are you sure that hasn't happened due to a bad connection in the plug rather than socket overload

 

[RF Lighting]

It was supplying the washer and dryer at my friends mothers house.

 

[rk696]

Your fitter is right and wrong at the same time.

As far as the regs go, you can run as many sockets as you like from the 13A FCU safely, as it is a fused spur, so it is impossible to overload any cables without the fuse blowing. If it was an unfused spur then no, you can't run spurs from spurs, as you can overload the cable running from the ring main.

However, any good electrician would either put another spur in, or convert the exisintg FCU, and the new socket to be part of the ring. If you are runnign both at once, and they are both calling for heat, as ricicle said, the fuse will keep blowing, as the system hasn't been designed for the expected demand.

 

[curium]

Your fitter is right and wrong at the same time.

As far as the regs go, you can run as many sockets as you like from the 13A FCU safely, as it is a fused spur, so it is impossible to overload any cables without the fuse blowing. If it was an unfused spur then no, you can't run spurs from spurs, as you can overload the cable running from the ring main.

However, any good electrician would either put another spur in, or convert the exisintg FCU, and the new socket to be part of the ring. If you are runnign both at once, and they are both calling for heat, as ricicle said, the fuse will keep blowing, as the system hasn't been designed for the expected demand.

Okay I understand now. Cheers guys.

I don't think the existing socket can be converted to be part of the ring as common practice now dictates that powerpoints which can't be accessed need to be controlled from an accessible switch and you can't put a switch in the ring, can you?

So the safest option would seem to be to install another switched fused connection unit on another spur from the ring supplying a second socket

 

[rk696]

Doesn't even need to be a fused one, as long as it's wired with the same size cable that the ring is wired with, it will be OK.

 

[JohnW2]

A double socket should not be used to supply two heavy loads such as a washing machine and a tumble dryer otherwise this has a habit of happening.

I can't really see how that can be blamed on supplying two heavy loads from one double socket - how would/could that result in such damage just around the L pin of one of the outlets (which would not have been carrying more than 13A)? Such localised damage is surely far more likely to be due to poor contact between the L pin and its receptacle - or, if the plug was similarly damaged, maybe between the plug's fuse and its L pin?

Kind Regards, John.
Edit: Whoops, just noticed ricicle's earlier post. However, I think I have gone into a bit more detail, so it's probably worth leaving my post here