Single oven to Double oven question

[Vanillaman]

Hi,

About to wire in a built under double oven to repalce a built under single oven.

Single oven was wired in on a 13amp plug. Previous installer has run 6mm cable from cooker control switch to surface mounted twin 13amp socket. Single oven was plugged in on one socket with hob ignitor connected to the other. Extractor fan is also connected to the socket via direct spur.

New double oven is 4.2kw rated so I know that the 13 amp plug is a no go. Can I replace the 13 amp twin socket with a junction box to supply the Oven , hob and extractor ?

Cheers

Vanilla

 

[mikhailfaradayski]

I believe this is notifiable work, your electrician would be able to advise on this and take care of the appropriate paperwork.

 

[Chri5]

Whats the fuse rating at the CU for the 6mm circuit ?

So far you have 4.2kw D/oven and a nominal 100w for the extractor, lets say 4.5kw or 4500w / 230v = 20A

So a 30/32A MCB would more than cover you.

The fan needs to be isolated and fused down, so a switched fuse spur would be best.

I'd tend to suggest a cooker switch point, with a 6mm tail going down to the cooker connection via a cooker outlet plate. If you go for a cooker switch with an integrated 13A socket your need to add 3kw to the load design and then use a 40A MCB.

A 6mm cable might not be able to cope, so you will need to consider distance of cable between CU and cooker and installation method for the cable (for derating).

 

[mikhailfaradayski]

Hi Chris,

You didn't give any advice on how the OP should deal with notification.

Maybe that would help aswell

 

[Vanillaman]

Hi Chri5

Thanks for the advice.

Existing CU has 32A MCB. Cooker circuit is also protected on the RCD circuit. Existing cooker control switch has integrated 13amp socket. 6mm tail runs approx 2m down to existing double 13amp socket, hob ignitor is plugged in here. 2.5mm spur runs from back of 13 amp socket up to extractor but no fuse/switch present here that I can see (fused isolator switch may be installed behind extractor cowl but I doubt it.

I'm guessing that this isn't a DIY job after all.

 

[mikhailfaradayski]

Hi Vanillaman,

I'm guessing that this isn't a DIY job after all.

Correct.


Dont' wish to sound rude or un-helpful ( there are others here who deal with that ) but do you understand what is mean't by 'notifiable work'

If so, how are you dealing with it?

 

[Vanillaman]

Dont' wish to sound rude or un-helpful ( there are others here who deal with that ) but do you understand what is mean't by 'notifiable work'

If so, how are you dealing with it?

Until posting this morning I hadn't considered the work notifiable. I now understand that the LABC need to be notified of the work so that it can be inspected OR it needs to be carried out by a qualified sparky who should complete and submit the part P for me.

Or have I misunderstood ?

 

[Chri5]

Hi Chris,

You didn't give any advice on how the OP should deal with notification.

Maybe that would help aswell

I avoid the issue all together now ! I fully understand the requirements for Part P, scheme registration et all.
I answer asked questions with technical rather that regulatory advice, reason being that 95% of post answers would be "do you understand Part P and the requirements for notification" and not the answer an OP wants.

Maybe it would be better if we all had a sig at the base of every response detailing the requirements

 

[ColJack]

as said, Part-P notifiable etc.etc.. look it up in the WIKI..

now..
change the double socket backbox to a dual backbox and fit a single socket for the hob ignitor and a cooker connection unit for the oven ( as shown below.. )
View media item 10929 View media item 10930
the extract hood will need to be looked into.. if it has a fused spur or socket outlet behind the cowl then it's ok..

 

[Vanillaman]

thanks for all the advice. I didn't know you could get a dual back box.. that was what I wanted to do but didn't know how.

P.S. Original single oven was fitted last year but my girlfriend hasn't got a part p cert to cover the work.. is this normal ? Who should I take it up with ?

 

[Chri5]

Hi Chris,

You didn't give any advice on how the OP should deal with notification.

Maybe that would help aswell

Noted- see new sig

 

[mikhailfaradayski]

Hi Chris,

You didn't give any advice on how the OP should deal with notification.

Maybe that would help aswell

Noted- see new sig

good idea

 

[Goldberg]

If you go for a cooker switch with an integrated 13A socket your need to add 3kw to the load design and then use a 40A MCB.

I disagree.

4.2 + 0.1 + 3.0 = 7.3kW, which would draw less than 31A, so a 32A MCB would be the correct CPD, not 40A.

A 6mm cable might not be able to cope, so you will need to consider distance of cable between CU and cooker and installation method for the cable (for derating).

It seems fairly likely to me that a 6mm² T&E cable would cope with 31A.

 

[ColJack]

they only add 5A for a socket on the cooker switch don't they?