First Fix Kitchen Wiring

Hi All
This is a question regarding built in cookers and isolation. I am in the process of building an extension and will soon be putting the studding up etc and doing the first fix for the electrics.

There will be 2 built in cookers
I have not checked (I will) but i am pretty sure that the cooker unit has an open back which is where the plug socket will go. This will be a blank socket (no switch). Regarding the isolation. I was thinking about putting this in either the cupboard above OR the cupboard below BUT what i am not sure is whether i put it in the wall and cut a square or hole in the back of the cupboard or whether i should build the isolator into the cupboard itself.

Either way is a bit of an arse.

Lee

Heres a question, if i was to put each cooker on its own circuit (which it is going to be) can i just use the consumer unit as the isolator? Each cooker will have its own separate circuit on the board.

1) I have seen no requirement for isolation.
2) To isolated both line and neutral are switched.
3) For things like chip pan fire there is a good reason for local isolation that can be used even when you can't get near the cooker, but to be any use it needs to be easy access and away from cooker, so not inside any cupboard.

You really need a risk assessment, if some thing goes wrong how will you switch it off? For my house if no isolator it would be out the back door down a set of steps, then under main house in flat under it, grab a set of steps then turn off RCBO. But in mothers old house the kitchen had it's own consumer unit in the kitchen so three steps to the RCBO, and the cooker isolator was behind the cooker so rather useless.

In the main the isolator is used for maintenance, it allows the cooker to be switched off in sight of the person doing the repair, but we all know it should be locked off, and I have a unit to take a lock and lock off the RCBO, but no way to fit a lock to cooker isolator.

Yes since in view I would likely take a chance and not lock off, but also know that is wrong. I should walk around to the consumer unit. And again my RCBO only switches the line, so OK with a TN system but not a TT system.

So yes I would fit an Isolator in my kitchen. And it would be on the wall in plain view clearly marked what it is for far enough away so it could be used in case of fire, but not required.

Seems odd to see an isolator on an induction hob which must be about the safest, but with a gas cooker which must be about the most dangerous nothing.

If it was an industrial machine hitting the E stop kills all power including air, but in the home, big switch marked cooker, and turn it off and the gas cooker still burns.

I really dont know which way to jump here, in this kitchen there will be built in eye level cooker, built in eye level microwave and then another built in eye level cooker. I would say i could use a gang solution but this is only 20Amp so not possible. Only other solution without butchering the cupboards would be to install some sort of triple isolation device on the worktop where the splashback goes and do it from there but not see anything that looks nice.

20 amp may be grid switch? But if you wait some one else may have better option

Local isolation is not required for appliances.

If you want emergency switching for the ovens (not cookers) then one will be sufficient, obviously this will require one circuit which can cope with all the appliances. I.e the normal standard cooker circuit.

Yeah grid switch switch

Accessible isolation switches are required by building regs in Scotland. You can get 3x 32A grid switches on one 6-gang row in Click Minigrid range https://www.electrical2go.co.uk/minigrid-250v-32a-dp-switch-module-md032wh.html.

skenk said:

Accessible isolation switches are required by building regs in Scotland.

Click to expand...

Are you sure?

It seems a bit daft to state "accessible".

https://www.gov.scot/publications/building-standards-technical-handbook-2019-domestic/
4.8.5 access to manual controls
"Where sockets are concealed, such as to the rear of white goods in a kitchen, separate switching should be provided in an accessible position, to allow appliances to be isolated"

"SHOULD" right enough..

leevis said:

Heres a question, if i was to put each cooker on its own circuit (which it is going to be) can i just use the consumer unit as the isolator? Each cooker will have its own separate circuit on the board.

Click to expand...

Yes. Local isolation (to the cooker) is not required, but often fitted.

Hey those 32A ones look just the ticket. I think (will have to check) that the ovens and the microwave are 32A. There will be an induction hob in the island with additional extractor fan which i could also add to this but have a feeling the induction hob is 40A, i don't suppose a 32A switch will do in this case? I could also add the dishwasher and fridge freezer to this to tidy it up plus the extractor fan would be 6 switches. For the induction hob i guess this is going to have to be an inside the cupboard situation which is what it is i suppose, would be very nice to get these all in one place

just to make sure i am not totally missing the point here

I have various appliances going in

Microwave and Dishwasher (both 32A)
2 Overs (both 32A)
Induction Hob on island (40A)
Extractor fan (not too sure what the load will be on this but not a lot)

The question is, can i put all of these on a 20A switch? ie 20A Microwave, 20A Dishwasher, 20A Oven 1 etc or does it have to be a 32A switch for each relevant 32A appliance and then one of those big 45A cooker switches for the induction hob and put it in a cupboard on the island.

Would be so nice to have all of these in the one place though.

Microwave, dishwasher and ovens will not be 32A each.
If they have a plug then they will be less than 13A.

The hob might be (total of rings 40A) but that does not mean it will be using anything like that during operation.

For XXXXs and giggles though, if i was to create a bank of 6 x 32A grid switches, that would be overkill but ok right?

Should there be a fused connection in there somewhere?