Can you site isolating switches for kitchen appliances in a local cupboard?

Discussion in 'Electrics UK' started by askman, 26 Mar 2019.

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  1. askman

    askman

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    I'm trying to plan out my new kitchen and want to understand the requirements for local isolation to (integrated) appliances. I will be having the following:
    • Dishwasher
    • Washer-dryer
    • Fridge-freezer
    • Electric oven
    • Combi microwave / grill
    • Induction hob
    • Extractor fan
    I would like to do the switching as following - dedicated switch for the hob which will be on its own radial circuit, have the microwave and oven together on a second radial circuit and have a dedicated switch to an unswitched double socket for these, further individual switches for the fridge freezer and extractor, and a combined switch for a double socket for the dishwasher and washer-dryer.

    Questions are as follows:

    Can this be done as I've outlined, i.e. combining some appliances to a single switch?

    Do the switches need to be exposed or can they be placed in accessible cupboards local to the appliances, i.e not behind the appliances?
     
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  3. Taylortwocities

    Taylortwocities

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    Why do you think you need to have isolation switches?
     
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  4. winston1

    winston1

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    There are NO requirements for local isolation. The various MCBs in your CU provide any required isolation.
     
  5. Taylortwocities

    Taylortwocities

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    Unless double pole isolation is needed. But then, of course, you just pull out the plug, or turn off the switch on the socket.
     
  6. bernardgreen

    bernardgreen

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    If the micro-wave and the oven share the same MCB then local double pole isolation would be a good thing.

    Reason being that if one of them developed a fault which prevented the RCD from being reset until the offendinf items had been disconnected from the supply.

    If the items was hardwired in then a hot dinner would be delayed until that disconnection was achieved.

    If there was a fire on the hobs then easy and rapid access to a means of removing power from the hob would assist in the immediate fighting of the fire.
     
  7. Taylortwocities

    Taylortwocities

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    Do you know how many reports there have been of a fire on an INDUCTION hob????:rolleyes::rolleyes:
     
  8. AndyPRK

    AndyPRK

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    THese are integrated appliances.

    I did see a youtube video of with a cupboard full of isolation switches. Looked a mess
     
  9. EFLImpudence

    EFLImpudence

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    Cupboards are places you put things you don't need.
     
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  11. bernardgreen

    bernardgreen

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    No, but I do know there has been at least one
     
  12. ericmark

    ericmark

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    As said only appliances requiring local isolation are those with a motor over a set size, it was considered years ago that isolation was sensible for washing machines as before they auto switched off with unbalance it was known for them to have loose weights and roam across the room smashing anything in their way, but today they auto switch off if not balanced. Any other appliance you can switch off at the switch on the appliance.

    However the switch is often single pole so if there is earth leakage problems you need another method to switch off the neutral and well as live, but in the main we can drag it out and unplug.

    For tradesmen to work on your appliance they must know it's isolated so where you can't unplug having an isolator makes sense, with for example the cooker, however it is common for gas cookers not to have isolators so why should electric? Even when gas cookers are plugged in, you still need it unplugging by a gas safe guy as the sockets often leak and you don't have equipment to test. So no rule saying must be local isolator.

    However you do need a method to isolate and although you can get double pole switching single width RCBO's for some consumer units, you can't get double pole single width MCB's to fit the consumer unit, so since technically neutral is considered as live, you can't isolate without turning off whole RCD set of MCB's or whole house.

    So it does make sense to have a method of isolation without turning off other things, so cooker isolator although not technically required, it is a really good idea.

    Also many fridge/freezers can't be turned completely off at the units own controls, and full of food you often can't move it, so a method to turn off is again a good idea.

    So a 13 amp plug must be in free air as it has a fuse which produces heat and needs to cool, the same to some extent with a FCU although some heat can go into the wall you do need to be able to change the fuse. But a simple switch/isolator does not produce heat unless faulty so you could have switches at the back of a cupboard although it would be hard to reach.

    Kitchen in this house has a small consumer unit just for the kitchen right by the back door, in real terms there was no need at all for oven isolators, hob isolators, or any others, but the electricians doing the work insisted on fitting them. The hob isolator is always turned off and the RBCO feeding the hob isolator is also turned off, and there is a plug in Lidi induction hob sitting on top of the halogen hob as halogen so useless, so was glad I could isolated the hob.
     
  13. JohnW2

    JohnW2

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    As I'm sure you know, even if it is considered to be 'live', isolation per BS7671 does not require disconnection of the neutral in a TN installation.

    Kind Regards, John
     
  14. ericmark

    ericmark

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    I know our induction hob on the Belling cooker auto switches down if the surface exceeds a set temperature and then off if it continues to rise, however not seen anything on the instructions for cheap Lidi portable induction hob, I do see your point be it a fire or rapid movement of the appliance then you may not be able to use the built in switch. So it would depend on location of the consumer unit, clearly a consumer unit in a locked garage is a problem, but one in the kitchen is not, so it comes down to risk assessment.

    We all tend to look at our own houses, and forget that some houses with integral garages have been built with no side door into the garage and an up and over door which can be blocked by a car or locked, although in this house the kitchen consumer unit is right by front door, the main one is under the stairs where there is a tendency to block assess.

    Some garage door fitters were daft enough with my dads house to fit an electric door to garage without manual controls with no side doors and consumer unit inside the garage. So mistakes are made.
     
  15. askman

    askman

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    Thanks for the input so far all.

    Perhaps I should have been clearer: I know that this isn't a statutory requirement under the BS, but I'd like to have some sort of isolation - even if just for the oven, microwave and hob for my peace of mind as much as anything. I'll check through the manufacturers' literature to see what they state is required.

    My CU is in the cupboard under the stairs which is accessed from the kitchen so maybe I will settle for switched sockets and further isolation from the board instead of dedicated switches in the kitchen.
     
  16. ericmark

    ericmark

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    One we don't know if it is TN and two neutral earth faults do need some method to remove the fault, we are told the supply must be split into circuits however it seems people don't consider a RCD to form a circuit, it is a current controlled device so technically it does form a circuit and in the sprite of the regulations we know we should ensure a fault with one circuit will not stop another from working, however I had to stop the electrician wiring up this house from putting the sub consumer unit from kitchen on to the RCD in the main consumer unit, had I not stopped him all this house would have been on two circuits, as it is there are 6 RCD protected circuits.

    It is all too easy for us to look at our own house and say yes that's OK as it would be in our house, there are houses where to turn off MCB's and RCD's you have to leave house and re-enter by another door.
     
  17. JohnW2

    JohnW2

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    Not, I think, in terms of the BS7671 definition of "a circuit", which talks in terms of protection of an assembly of electrical equipment against overcurrent by the same device - and I really don't think that many people would say that an RCD 'protects against overcurrent' (even though it operates when the residual current exceeds a certain value), would they?

    Kind Regards, John
     
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