Cooker Switch

[MrsGarner]

I have just had the electrics done in a house that I have just bought.

I dont want to ask the electrician this question as he is a complete tw@t and weve had to spend hours removing conduit that is too big for the channels and replacing it and various other things.

Weve had a cooker switch installed- this switch is linked to the single socket that the cooker will be plugged into so that we can isolate it.

The cooker switch runs directly off the kitchen ring main and doesnt have its own connection is this ok? also its the same cabling used for all the other electrics - BUT my dad thinks (and he isnt an electrician so hoping for some clarification) that this should be a thicker cable is that right or not? Or does it depend on the type of cooker?

 

[ericmark]

In the appendix of BS7671:2008 it states that permanent items over 2kW should not be connected to the ring. I think it unlikely you will have any cooker under 2kW so it should have a dedicated supply.

However washing machine, tumble drier and dishwasher also fall into that category and are often supplied from a "kitchen ring" but often the "kitchen ring" is not a true ring but conductors in parallel feeding a grid switch done that way as hard to get 4mm² into grid switch but two x 2.5mm² will fit.

I say all this because it is easy to jump in and give the simple answer all cookers should have a dedicated supply but there are a few exceptions.

In the main both oven and hob or stand alone unit are given a 32A supply. There are exceptions. My mothers domino hob runs from a 13A FCU and there are cookers like the Baby Belling specially designed to run on a 13A supply.

Some of the larger hobs also have power sharing systems to allow running from 13A supply but these are not that common.

As an electrician I would consider the 32A supply for at least one stand alone cooker was standard in any home. The only exception would be a caravan or boat. Even back as far as 1980 standard minimum was cooker, ring, immersion, lights with 30, 30, 16, 6 amp fuses today the lights and ring likely split in two so that one can go to each RCD so split 6 way is likely smallest consumer unit used in a house today.

 

[riveralt]

In the appendix of BS7671:2008 it states that permanent items over 2kW should not be connected to the ring. I think it unlikely you will have any cooker under 2kW so it should have a dedicated supply.

That should be 'gives guidance' (informative)...pedantic but important.
While it is not the way I would do it, I don't see any problem with the arrangement made - clearly the 'cooker' (oven maybe) manufacturers have seen fit to fit a 13Amp plug to the appliance.
As we know ovens are never on full power for very long hence the significant diversity factor allowed.
I suppose the only issue might be one of future proofing the circuit(s) design but that may have been limited by the customers demands or cost constraints.

 

[PrenticeBoyofDerry]

If it is a cooker (hob and oven combined) it is very unlikely that a 13A supply would be sufficient for the load. Therefore what your alleged electrician has installed would not be suitable nor compliant with the "wiring regulations"

As erickmark has stated in above post, a cooking appliance that demands an out put equal or greater than 2kW should be on it's own circuit.

Other things should also be taken in to consideration.
*The cables are installed if buried within walls in those permitted if not mechanically protected.
*The cables if buried and not mechanically protected, have additional 30mA RCD (if not already on the circuit)
*The socket should be 30mA RCD protected, if the cable is surface mounted.

I would personally check out this persons credentials, are aware if they are registered with a domestic scheme provider? Ask that question!
If they claim to be it can be checked by either contacting the company they claim to be registered or searching by filling their details in here.
http://www.competentperson.co.uk/
That is not to say an unregistered electrician cannot do this work, but they are limited to what they can legal do without the consent of building controls and will still have to issue you with documents relating to the installation, including relevant schedules of inspection and test results.