Is there anything wrong with having a hob and oven on 30A

[christopher007]

Hi I'm new here hope you can help me. just pulled out my oven to put a new one in and the new one needs a 20A supply apparantly, can I connect it to the 30A supply there which is supplying the electric hob (hob is 6kw), if I use a 4mm flex from the flex connection plate? Thanks for your help.

 

[echoes]

So long as the instructions don't bang on about fusing down, then yes they can share the 30A supply.
What model oven is it?

 

[flameport]

Yes.

 

[PrenticeBoyofDerry]

Are intending to run both appliances, hob and oven off the same circuit?

 

[christopher007]

Hi Thanks. Yes would be running the hob and oven on the same circuit.

 

[PrenticeBoyofDerry]

Taking diversity in to account, I will agree with the sages.

 

[ajrobb]

IEE On-site Guide, Appendix 8.4 Cooker circuits in household and similar premises:
"A 30 A or 32 A circuit is usually appropriate for household or similar cookers or rating up to 15 kW." ... "A circuit of rating exceeding 15 A but not exceeding 50 A may supply two or more cooking appliances where these are installed in one room."... "Where two stationary cooking appliances are installed in one room, one switch may be used to control both appliances provided that neither appliance is more than 2 m from the switch."

 

[PrenticeBoyofDerry]

That's according to table 1A or 1B but being pedantic, it's not strictly true.
If the addition of a CCU with socket outlet was introduced it would then take the rating close to 35A.
But I ain't one to cause a rumpus

 

[ajrobb]

OSG Appendix 1, Table 1A:
For "household cooking appliance", the "current demand to be assumed" is "The first 10 A of the rated current plus 30% of the remainder of the rated current plus 5 A if a socket-outlet is incorporated in the control unit."

A 32 A circuit can supply 19 kW of household cooking appliances without a socket-outlet.

230 × (10 + (32 - 10) ÷ 0.3) = 19167 W or 19 kW

The 15 kW comes from allowing 5 A for the socket-outlet on the CCU:

230 × (10 + (32 - 5 - 10) ÷ 0.3) = 15333W or 15 kW

Now, I am not happy applying the diversity correction to circuits smaller than 32 A, but just for a laugh:

For the proposed 20 A circuit WITH a socket-outlet that would be

230 × (10 + (20 - 5 - 10) ÷ 0.3) = 6133 W or 6 kW

For a 20 A circuit without a socket-outlet that would be 10 kW

For a 13 A FCU that would be 4.6 kW