463.1.3 Functional Switching (Control).

No, there is no need for a separate switch, the CB or RCD for that circuit can provide both isolation and functional switching.

Even if appliances are fed from say a ring final circuit? Using the M.C.B. could be inconvenient.  That would mean disconnecting several appliances just to disconnect one for peace of mind or safety.

Z.

Zoomy, you've been on the Woodforde's again!

I interpret 463.1.3 as meaning that appliances should have on-off switches, so for example, closing the switch above the counter shouldn't turn on all the rings. I doubt that any domestic appliance would be controlled in that way.

However, an isolator is highly desirable. There could be one each for the oven and hob, or there could be one for the cooker as a whole.

No Chris, I am totally tea-total.

My response was to just using the circuit M.C.B or R.C.D. as suggested above for control and/or isolation.

So, are you saying that appliances should have local isolator switches and that they should not rely upon their own integral controls only? Separate easily accessible switches sound like a good idea for appliances that may cover a supplying socket such as a built in fridge or oven/hob.

Z.

Agree with Chris in that cooking appliances should have a separate means of isolating the source of supply in an emergency, to take away the source of heat. but that is not functional switching. With domestic gas appliances, this can only practically be done at the gas meter. Each appliance must have a gas isolation valve, but for maintenance rather than for emergency shut off. 

Fridges/freezers needing to be switched off for defrosting might be considered functional, if the appliance does not have that facility, some old ones don't, and if the plug is behind the fridge it might be a pain.

I have a customer who has a new build. The builder has left  several issues with the control of appliances, especially in the kitchen, with one switch controlling several different appliances etc. I am looking for ammo to defend the customer against the builder. 463.1.3 applies primarily to control of current using equipment not isolation. 463.1.1. may loosely apply but is not specific enough in my opinion to use in this case. Some new fridges are now self de-frosting and need no switching off externally.

Personally I think that all individual appliances should have a convenient but remote isolation switch. Some hobs have touch controls on the horizontal glass top. The controls could not safely be used in the case of a chip pan fire, so a separate wall switch would be essential to turn off the hob.

Z.

I don't see it like that at all Z. It is simply saying that a power-using item must be able to be switched off. Appliances that are plugged in obviously have this, and a fridge built-in does not. It is not saying anything about an emergency (as you quote) or even isolation for cleaning or maintenance. Functional switching is simply turning something on or off. I rather hope the grid switch turning off every kitchen item has died the death,  If you have a fire surely you want to turn off all the electricity so the CU or whatever is perfectly adequate as it provides 2 pole isolation. Then you can get the hose out or whatever. It is very wise to have a fire blanket in the kitchen, but that is not a BS7671 scope, it belongs in the BR.

Zoomup said:

I have a customer who has a new build. The builder has left  several issues with the control of appliances, especially in the kitchen, with one switch controlling several different appliances etc. I am looking for ammo to defend the customer against the builder.

Unfortunately, I don't think that BS 7671 provides the ammo.

It's a matter of contract. Were there any formal designs, and if so, did the builder follow them? If there were no formal designs, what was agreed between the customer and the builder?

I think that we all know the benefits of local isolation, but if they were not agreed in advance, it is difficult to see what can be done about it.

What about a modern dish washer that I saw today that has controls on the top edge of the bottom hinged door. Once a cycle has started the door is locked shut until the end of the cycle.  Access to the functional switching is then impossible until the cycle has ended and the door opened.

And...............the supply for the dish washer is from a cooker circuit protected by a B32 M.C.B. The dish washer has no local switch at all. If it is plugged into a socket, the socket must be behind the appliance and is inaccessible.

But the cooker switch does turn it off as well as the hob and oven. So we have three appliances connected to the cooker circuit where one is not obviously switched.

Would you expect a cooker switch to control a dishwasher?

In a panic, such as when an appliance catches fire or tries to flood the floor, can we be cool headed enough to turn off at the consumer unit? And what if that is situated say in the garage, and not conveniently situated. What if we accidently turn off the lights as well at night thus introducing an additional hazard during an emergency like an appliance fire or a flooding washing machine

Local isolation is important.

Z.

Isolation is not functional switching Z, you are confusing the two. Whilst your kitchen in question is unusual, it is not contrary to BS7671, and I really cannot see that cooker switch being used for functional switching. It is used to isolate the connected appliances, and if you think it is not clear why not add a label saying what it does isolate? I'm sure you have a suitable label maker for CU circuit labels etc. I have a nice Dymo one that has modes to do just that. Others may note the diversified load!