Help! Wiring for 4.3Kw cooker

[candidcamel]

All,

Firstly, I'm not any kind of electrician, but I am a customer of a cowboy electrician!!

I have 2.5mm2 cable running around my kitchen and I asked my 'electrician' if this would be ok to wire up a 30Amp 4.3Kw oven (the hob is gas) and he said 'yeah, should be ok'. However, looking on various forums this appears to be inaccurate. I don't want a meltdown or a fire in my new house....can anybody give me some professional advice from a handbook?

Any pro help would be greatly appreciated.

Kind regards
Gregg

 

[i=p/u]

i assume cooker is on own circuit as they say over 3kw , should be .

4300w/230v= 18.6A , should be ok .

2.5mm t&e cable can take 27A clipped direct.. if has going through walls and ambient is high could be different.....

 

[nickblake]

4.3 kw oven can be wired in 2.5mm and protected by a 20 amp mcb no higher ,this is as long as nothing else is on the circuit too as you say it runs round the kitchen so could be an idea to check , also like to point out to you that any work carried out in a kitchen is notifiable work under part P of the building regs and should be carried out by a qualified and regestered electrician

 

[candidcamel]

i=p/u

Thanks for your advice. Sorry for being electrically dumb, but when the manufacturers say that it requires a 30 amp supply, are they just saying this to be on the safe side, given that you're saying it's actually an 18.6A applicance?

FYI from the consumer unit the cable will run 6.5m under the floorboards and then up directly into the wall where the dual fuel range oven will sit.

Thanks for your previous comments though, much obliged.
Gregg

 

[candidcamel]

Nick,

Appreciate your comments. Like I said I'm not electrician, so I don't know how to check the ampage of the mcb - I guess this is just another switch on the consumer unit...

It's difficult to say what he's doing in the kitchen because he has steel back boxes (without grommets) linked up with 2.5mm2 cable. I asked him to put in isolator switches, but there are no back boxes present for these....and this guy is apparently NIC EIC qualified!!! Oh, and he's also an alcoholic...

Sorry to bleat on...you are the good guys. I just kicked the guy out of my house!

Many thanks for your help
Gregg

 

[nickblake]

no your not electronically bumb youve a question so your asking for an answer thats why were here , if you have a 4.3 kw oven you are correct in saying the maximum demand is 18.7 amps ,thats maximum load now im assuming that the oven also has a grill built in too , you may well find that the oven is 2kw and the grill is 2.3 kw i dont know as ive not seen the oven but the loading will be fine on a 2.5mm cable protected by a 20 amp MCB , not a rewireable fuse , if its a rewireable fuse then the cable will have to be 6mm

hope this helps

 

[nickblake]

Nick,

Appreciate your comments. Like I said I'm not electrician, so I don't know how to check the ampage of the mcb - I guess this is just another switch on the consumer unit...

It's difficult to say what he's doing in the kitchen because he has steel back boxes (without grommets) linked up with 2.5mm2 cable. I asked him to put in isolator switches, but there are no back boxes present for these....and this guy is apparently NIC EIC qualified!!! Oh, and he's also an alcoholic...

Sorry to bleat on...you are the good guys. I just kicked the guy out of my house!

Many thanks for your help
Gregg

if you are concerned with the quality of his work and he states that he is NIC approved i would contact the NIC ,and check he is regestered ,if he is then complain as buy what you have said he is not carrying out the work to a satisfactory standard http://niceic.com/

nick

 

[candidcamel]

Sorry, Nick, but how will I know if its a rewireable fuse?

Regards his accreditation, I'm looking into how I complain to NICEIC, but what I really want is someone to give his work the once over and finish the job. Of course, I need a certificate for the work and the electricians insurance details.

Cheers again for your advice

 

[BluSparx]

The certificate should have been provided by the guy who installed again if not contact NICEIC as he is saying he is registered with them I take it you have a quote/reciept for the work

 

[nickblake]

Sorry, Nick, but how will I know if its a rewireable fuse?

Regards his accreditation, I'm looking into how I complain to NICEIC, but what I really want is someone to give his work the once over and finish the job. Of course, I need a certificate for the work and the electricians insurance details.

Cheers again for your advice

Rewirable fuses look like dominos 2 coloured dots ,either white ,blue ,yellow or red , if they are MCB's the will have a number 6 a ,16 a ,20a or 32 a if they are BSEN60989 or BS3871 they will be 5a 15a 20a or 30a

 

[ezzzekiel]

i=p/u

but when the manufacturers say that it requires a 30 amp supply, are they just saying this to be on the safe side, given that you're saying it's actually an 18.6A applicance?

Gregg

although the calcs for design current are correct you should always follow manufacturers instructions as these take presedence over regs so in my opinion if it asks for a 30a supply then thats what you give it.

 

[candidcamel]

And if I take the manufacturers recommendations, what size wiring do I need? 6mm2 or 10mm2?

Also, whilst I'm on...

Under regulation 522.8.1 - 'A wiring system shall be selected and erected to avoid during installation, use or maintenance,
damage to the sheath or insulation of cables and their terminations' - are rubber grommets required for steel back boxes. There is comment on this subject on these forums but there is arguement for and against. Does anyone have a definitive answer, or this just a judgement call? At the moment the sockets aren't plastered in so I can clearly see that the grommets aren't in situ.

Thanks you all for your guidance

 

[i=p/u]

niceic have page on their website about people claiming to be registered that are not.. name and shame pagee.. few people on it, or they made them up...

 

[candidcamel]

Nick,

There are two 32A MCBs on the consumer unit so I guess that one of those would be used for the oven. Looks like he was right when he said 2.5mm2 cable was ok! Sadly his workmanship has undermined my faith in his electrical knowledge.

Once again Nick, thanks.

 

[candidcamel]

Yeah, saw that. He's not on the list. Thanks though.