isolation requirements for appliances

[Ben Blaukopf]

Finishing off the last few things on the kitchen wiring, prior to getting it insPected...

What are the requirements for isolation of appliances?

In the kitchen I have a boiler, which is currently isolated by an FCU in the airing cupboard upstairs? I assume that's sufficient - it's certainly pretty standard.

Other appliances are fridge/freezer and dishwasher, which are right next to each other. Both are freestanding, not built-in.

My options for these are:

a) Stick a socket behind the f/f at standard above-worktop height, plug it into that. Add an FCU at worktop height feeding a socket below worktop height, behind the dishwasher.

b) Add two FCUs above worktop, feeding two single sockets below worktop behind dishwasher, both appliances use these sockets.

c) Add a single FCU above worktop, feeding a double socket below worktop. I'm not 100% convinced by this though, as I can see that while it's okay for a dw + ff, someone in the future might put move the ff and put a washing machine there, which would draw a lot more current.

My preferred option is a), followed by c), but I need to make sure that it completely meets current regs, as well as making electrical sense. It will be a lot of hassle if the BCO wants anything changed...

[EricP]

Don't you use normal BS fused plugs in your home?

[robgraham]

Hmm - I did do my kitchen some years ago but it never dawned on me that I needed to do anything but supply a switched socket behind the appliance.

Rob

[chris French]

In message , Ben Blaukopf writes

Is, ISTR all the ones I have had/see have the FCU near the boiler. Anyway, AIUI, having the isolation in a remote location from the appliance is ok as long as it can be locked isolated (with an FCU, a lock through the fuse carrier. Personally I wouldn't like it, for one thing it's inconvenient.

For both of these there is no need for FCU's, the fusing is taken care of by the fuse in the plug. A 20 A switch is sufficient to feed a remote socket. Either a or c with the FCU replaced by a switch is fine depending on your preference (I'd use a socket alone if accessible, switch via a 20A switch if hidden by worktop, behind appliance etc.

More to the point, isolating the device would require moving them out.

go for a then, with the switch.

[Lobster]

What is adjacent to these appliances? Just that my preferred option is (d), which is to fit a standard switched socket to the wall behind an adjacent unit, below worktop level... you cut a hand-size holes in the back panel of said unit and in the side-wall behind the back panel into the space where the appliances are, so you can pass the plugs through to reach the socket.

This method requires the minimum possible wiring work; means you don't have to hardwire the appliances using FCUs and can retain the factory-fitted plug; and you can easily access the plug to change a fuse or switch off the socket, or to unplug the appliance to remove it.

David

[Ben Blaukopf]

e) has just occurred to me, which is a double socket behind the fridge, with the d/w plugged into that.... Does require pulling the fridge out a few inches to remove any plugs, but that's not really a big deal. The switch should be reachable without any problems...

The trouble with d) is that for various reasons the adjacent wall won't be very accessible - otherwise that's exactly what I'd do....

[John Rumm]

Personally I prefer the FCU to be close to the boiler since while working on the boiler you may need to switch the power to it several times.

No need for FCUs anywhere really.

The "nicest" way of doing this is to ring in 20A double pole faceplate switches, and drop a single wire from each to a socket below worktop height. That way you can isolate the socket without having to move the appliance. For really posh you can use switches with neon indicators to show the appliance is on.

Na, just adds current limitations without gaining anything.

As someone else suggested, an quick and easy way is a socket on the wall below worktop height in an adjacent unit can work well. Cut a hole in the side of the unit to pass the appliance flex through. That way you can isolate the appliance just by opening the door and switching off or pulling the plug.

[Dave Plowman (News)]

My ancient Potterton has a plug/socket within it for the mains supply which completely isolates the boiler electrics. Which of course are basic anyway. But it still seems a sensible arrangement for any boiler no matter how sophisticated the electrics.

[Bob Eager]

I also prefer it there so that you can ensure that no-one else erroneously energises the circuit.

That happened to me many years ago...I was cutting cables having climbed up a steel stage gantry. Someone energised one of the cables in error.

I still have the (uninsulated) burned wire cutters...the hole in them makes them a good wire stripper!