Wiring a single oven to a 13a plug?

FreeBear

jscott08 wrote: »

Given I haven't put my counters in yet, should I have this changed by an electrician to the dual plate chase further up the wall?

Not "should", but "need to" - The cooker switch should be a minimum of 300mm from the hob, and no more than 2m (recommendation, not a requirement). The cooker switch must be readily accessible, which means above the counter surface, not hidden in a cupboard, and certainly not directly above the hob.

The wall is going to have to be chased out and holes made to fit the wall boxes in - This needs to be done before the plasterer comes in, or any tiles are fitted.

tacpot12

Sorry jscott08, I've just seen an error the crept into my diversity calculation. I wrote 10A + (3/4 * 18.2A) + 13A when is should have been 10A + (0.3 * 18.2A) + 13A (as stated by Owain Moneysaver). This gives less than 32A so you would have been okay with a 32A Breaker. Oops!

I am a bit surprised that you have a 40A breaker on the cooker circuit, but if the electrician had the make and model numbers, he perhaps did know the demand and installed the correct size cable and 40A breaker to protect it.

Using the dual plate will allow you to connect 4mm cables - I agree that finding a 13A plug that you could connect 4mm cables into would have been nearly impossible.

I think I would get the cooker control unit repositioned and the dual plate fitted while you have access. It is more money and mess, but it does get the job done properly; if one of the appliances has a fault, being able to turn it off quickly could be very useful.

I'm not sure I would use your electrician again. He should have known where the cooker control unit needed to be positioned, and should have provided an outlet rather than just bringing the cable out at the bottom of the wall.

jscott08

FreeBear wrote: »

Not "should", but "need to" - The cooker switch should be a minimum of 300mm from the hob, and no more than 2m (recommendation, not a requirement). The cooker switch must be readily accessible, which means above the counter surface, not hidden in a cupboard, and certainly not directly above the hob.

The wall is going to have to be chased out and holes made to fit the wall boxes in - This needs to be done before the plasterer comes in, or any tiles are fitted.

tacpot12 wrote: »

Sorry jscott08, I've just seen an error the crept into my diversity calculation. I wrote 10A + (3/4 * 18.2A) + 13A when is should have been 10A + (0.3 * 18.2A) + 13A (as stated by Owain Moneysaver). This gives less than 32A so you would have been okay with a 32A Breaker. Oops!

I am a bit surprised that you have a 40A breaker on the cooker circuit, but if the electrician had the make and model numbers, he perhaps did know the demand and installed the correct size cable and 40A breaker to protect it.

Using the dual plate will allow you to connect 4mm cables - I agree that finding a 13A plug that you could connect 4mm cables into would have been nearly impossible.

I think I would get the cooker control unit repositioned and the dual plate fitted while you have access. It is more money and mess, but it does get the job done properly; if one of the appliances has a fault, being able to turn it off quickly could be very useful.

I'm not sure I would use your electrician again. He should have known where the cooker control unit needed to be positioned, and should have provided an outlet rather than just bringing the cable out at the bottom of the wall.

Thanks both for the info. Would I be able to put the switch in an adjacent wall cabinet? I've seen this in a fair few kitchens and would make sense. I can cut out the backboard so the switch would be easily accessible. If so, I can chase a channel 1meter vertical from where the switch currently is, allowing the box to be more than 30mm from the hob and any water, whilst still being within 2 meter.

What exactly would the order be here - mains to the dual plate, then each cable to seperate switches, then from each switch to each unit?

I will do the chasing in to the wall for these so would be good to know exactly what and where to put the cables and boxes, I will however get an electrician to do all of the actual wiring - i just want to be very precise with what I ask the (new) electrician this time round so it isnt done wrong

EDIT: just re read, would it go fuse box to single switch (above counter) -> drop down to dual plate behind cooker (where the current socket/ switch is) -> 2 separate 4mm cables out, one for cooker and one for hob?

Risteard

The GUIDANCE on diversity in the On-Site Guide is not an additional 13A for the socket outlet, but 5A as stated previously.

jscott08

So, just so I understand this correctly, would the best thing to do be the following:



chase the red line in to the wall from the fuse box to the counter level, then run the cable loose behind the counter/ on the floor till it reaches the start of the next red line. Then chase this second red line up to a switch which will be in the adjacent wall cabinet (the red box), from there running a cable (yellow line) down the same channel to a dual plate (yellow box, which will replace the socket/ switch already there). Then connect the hob and oven to these cables.

Does this all sound correct/ the best way for this to be done? Again I won't be doing the wiring myself here I will be getting an electrician, but as opinions seem to differ with things like this and I don't want to be ripped off, I wan't to be crystal clear with what I ask him

Owain_Moneysaver

jscott08 wrote: »

What exactly would the order be here - mains to the dual plate, then each cable to seperate switches, then from each switch to each unit?

Mains to the cooker switch, cable to the dual plate, then separate cable to the hob and the oven (if both are within 2 metres of the switch).

I don't like cooker switches in cupboards. They should be accessible and visible as someone who needs to operate it in an emergency might not know where it is.

Ectophile

Why does a 3kW oven need a 4mm flex? That's a ridiculous size for that load.


My oven just came with a normal size flex, and a 13A plug ready fitted on the end.

billymadbiker

It's probably suggesting 4mm to increase the heat resistance on the cable.

I have seen gas only hobs come with 2.5mm fitted and the only power requirement on them is the electric spark which probably only draws 0.001 or so of an amp.

bxboards

Ectophile wrote: »

Why does a 3kW oven need a 4mm flex? That's a ridiculous size for that load.


My oven just came with a normal size flex, and a 13A plug ready fitted on the end.

I've bought a Hoover brand oven and it too came with a fairly standard 13a flex and plug.

I recently bought another oven to fit and while looking at the ratings I think a 13amp plug would be fine, the instructions want this one hard-wired. Noticing a tenancy for this more and more.

But a oven is fairly typically happy plugged into a 13 amp. I actually plugged my oven into a 13amp to test it and as expected it was fine.

Risteard

billymadbiker wrote: »

It's probably suggesting 4mm to increase the heat resistance on the cable.

I have seen gas only hobs come with 2.5mm fitted and the only power requirement on them is the electric spark which probably only draws 0.001 or so of an amp.

Cross-sectional area is nothing to do with the temperature rating of the cable.