Cooker Spurs

[jm317]

Hi

Here is the problem. I need at least one spur from a cooker ring circuit is this setup OK ?

Mains wires come into the kitchen to a 30A junction box a 2.5mm twin and earth cable drops to a double socket that runs a plugged ceramic hob and single oven on 13Amp fuses and plugs. A spur is taken out of the junction box to run a washing machine again on twin and earth 2.5 and ideally I'd want a second socket for a microwave.

I think the cooker is OK on the lower grade wiring as they are fused13A plug appliances and if I replace the junction box with a cooker isolation switch and plug then maybe I can take a spur from this box for the washing machine. Upgrading the wiring to 6mm ? A separate spur from another plug isn't an option as they all have spurs and a new spur from the consumer box would be difficult.

Any thoughts appreciated.

JM

 

[JohnD]

You have described your proposed solution. Please describe the problem you are trying to solve:

What circuits do you have available?

What loads do you want to supply?

Are you in England or Wales?

 

[jm317]

The question is can a cooker ring circuit be used to supply spurs to run other domestic appliances and is my proposed solution reasonable ?

I'm in the UK, the cooker circuit is direct from the consumer box and the kitchen has its own ring circuit which I assume is part of the ground floor circuit.

emm loads.....well 1xceramic hob, 1xsingle electric oven, 1xwashing machine 1xmicrowave oven all of the cooker ring ? Don't have numbers to hand.

Thanks

JM

 

[JohnD]

OK.

So you don't know what power the cooker circuit is rated to supply, and you don't know what current the cooker takes.

You don't know what load there is on the circuit that supplies the kitchen sockets, and you don't know if it supplies sockets outside the kitchen. You don't seem to know if it is a ring or a radial, or what power it is rated to supply.

Can't help.

I am going to guess that you are in England or Wales (not Scotland or Northern Ireland). So this work, which is in a kitchen, is notifiable to your local authority Building Control office.

 

[jm317]

OK...you have little imagination and gonna make me work for a little information. I didn't say I'm gonna touch anything and blow myself up.. I'm just asking.

So the standard nominal supply voltage in domestic single-phase 50 Hz installations in the UK is 230 V. The cooker is on a 30A fuse so I'm guessing that gives me 7200 watts to play with.

An average ceramic hob is 3000W, single oven 900W, microwave is 850W and a washing machine 150W = 4900W ish ...so I have lots of watts left, 3 horse power of watts left !

any better now ?

JM

 

[JohnD]

OK...you have little imagination and gonna make me work for a little information. True

So the standard nominal supply voltage in domestic single-phase 50 Hz installations in the UK is 230 V. The cooker is on a 30A fuse so I'm guessing that gives me 7200 watts to play with. no, 30x 230 is 6900

An average ceramic hob is 3000W Wrong
single oven 900W Wrong
microwave is 850W Don't know yours
and a washing machine 150W Completely wrong

= 4900W ish Wrong
...so I have lots of watts left Wrong,

3 horse power of watts left !

any better now ? No.

JM

 

[davy_owen_88]

An average ceramic hob is 3000W, single oven 900W, microwave is 850W and a washing machine 150W = 4900W ish ...so I have lots of watts left, 3 horse power of watts left !

 

[jm317]

OK.....you got me there!!!!!!!

You just can't trust google ..

I'll get the numbers........


I'LL BE BACK........

 

[jm317]

Well it could have been a really old washing machine.....

Microwave: 0.9kW
Oven: 2.2kW
Hob: 6.7kW (wow)
Washing machine 1.2kW

Total 11kW

I'm all out of watts ? any suggestions ?

 

[JohnD]

Your cooker circuit will probably be adequate for the hob and oven, though it would be preferable to supply the oven independently.

You will need a socket circuit for everything else.

You need to establish if your kitchen sockets are on a ring or a radial, what is the rating of that circiit, and what else is supplied by that circuit.

 

[jm317]

The rest of the kitchen and ground floor is supplied by a 30A ring.
Usual stuff TV, video, DVD, Kettle, fridge, extractor, toaster etc.

cheers

JM

 

[JohnD]

Then use that as the socket circuit for your other appliances. This can be done by extending the ring. A better solution would be to run the kitchen on a new circuit with ample outlets. You mention a 30A fuse. This suggests the installation is very old as modern ones use a 32A MCB. An old installation is likely to have other defects.You have already indicated that the wiring is ramshackle and has insufficient outlets.

You said "2.5mm twin and earth cable drops to a double socket that runs a plugged ceramic hob and single oven on 13Amp fuses and plugs" This is wrong. You need a Cooker switch and 6mm cable for the hob. Not plugs and sockets.

 

[jm317]

Yes, the installation is old ~ circa 1973.

With regards the cooker installation the 6mm cable that comes in from the wall goes to a 30A junction box to 2.5mm to a double socket, to the plugged appliances. The appliances are new and came with plugs attached. The appliance cables are the weakest link so is upgrading the wiring really or making any difference ? Is an isolator switch necessary if the socket has switches on it ?

Extending the ring for the other appliances seems best.

Thanks for your help.

JM

 

[JohnD]

If it is a 4-ring ceramic hob, then it is not safe through a plug and socket, it needs a cooker switch and 6mm cable.

 

[Clitheroe]

Yes

I hate to say this, but although I havent read everything thoroughly it sounds too me that the wiring is very dodgy like some are saying.