Re:6mm cable fiteted to a 10.7KW cooker

[dx90]

I have a new cooker that is rated 9.8KW – 10.7KW. The distance from the consumer unit to the cooker is about 13 meters and the cable is 6mm. I have just had this cable and cooker installed by a qualified electrician. I am a bit worried that the cable is not going to be future proof and only just within the rated spec for this cooker.
My question is, do I ask for the cable to reinstall with a 10mm cable or do you think it is ok to use the fitted 6mm cable with this cooker?
I was told it would be fine.

Thanks

 

[securespark]

Diversity brings the figure down, but flc at 230V is 46.52A. 6milli is maxed out at 46A clipped direct with no correction factors.

Volt drop at 13m is OK. You are not future proof (in terms of flc), but you're OK with diversity. But what size is the CPD?

 

[pdenni]

hi there

at its maximum output 10.7kw pulls 46 amps without allowing for cable length or diversity, so in answer to your question you need a 10mm cable with a suitable isolator (50amp). i would be interested to know what rated mcb has been installed to protect it.

 

[Taylortwocities]

At full load10.7KW is 46 amps. If you look at diversity (for a domestic cooker) you would end up at around 25A.

Your sparky may have taken that view as designer, but he wont be there on Xmas morning when the whole thing is going full blast. But that's the dilemma, will all of the ovens, grills and rings all ever be on full blast?

PS what's the fuse value on that 6mm cable?

 

[dx90]

What does cpd mean?
MCB is a NSB40.
The electrician is coming back in a weeks time to finnish off the other work and complete the part P. I did tell him my concerns about the cable and he said if it tripped out by the time he comes back he will change it, but hes sure it won't. We took up all carpets, took out all furniture and flooring in the bathroom to get the cable through and by all accounts it was a pig to do. So hes not keen on replacing it. But like someone said its not future proof and I don't want to take the house apart in the future to have 10mm put in nor do I want to upset the electrician either. So I don't know what to do.
I am willing to buy my own cable and reroute it myself, but I would have to take there new cable out to go back through all the holes drilled in the floor joists and they also used special rods to get it the wire down behind the very narrow stud work in the kitchen.
He did say that that kind of high rateing was one of the highest hes ever put in and it was unexpexted.

Whats so annoying is that we put in a 10.5KW shower and he used 10mm cable for that and not for the cooker.

Thanks

 

[cleverspark]

since the cable is protected by a 40A MCB you could turn on the cooker and all hobs and therefore using it at full power, if the MCB keeps tripping out this will be an excellent way to show the sparky on his return and therefore he will have no option but to increase the breaker and cable.
the reason he has used 10mm for the shower will be for the fact that he has used diversity for the cooker, or probably more commonly as a lot of electricians are stuck in their ways and always say 6mm cable and 40A breaker for oven cooker instalation.
and before i get slated by all the full time sparky's I am just saying that a lot of them do.
no offence intended.
Cheers

P.S. this site is great

 

[pdenni]

just to add to this subject if the cable is going through numerous joists and through stud walls which are probably insulated you would definately need a 10mm cable and uprate the mcb.

 

[dx90]

Does anyone know how much the voltage can fluctuate, max and minimum?

Have I got this correct. If the voltage drops the amps needed increases?

Do you think I'm being unreasonable if I ask for the cable to be changed to a 10.0mm from the 6mm that has been put in?

I know its a awkward job to do but I have taken half the house apart for the electrician to gain access and I will be in no position to in the future.


Thanks

 

[securespark]

You could always compromise on the deal. Go Dutch on the cost to upgrade, maybe?

 

[Softus]

just to add to this subject if the cable is going through numerous joists and through stud walls which are probably insulated you would definately need a 10mm cable and uprate the mcb.

To be pedantic, if the walls are "probably" insulated, then you only "probably" need 10mm cable.

Does anyone know how much the voltage can fluctuate, max and minimum?

230V +10% -6% .

Have I got this correct. If the voltage drops the amps needed increases?

No. The Amps drawn will decrease in direct proportion.

Do you think I'm being unreasonable if I ask for the cable to be changed to a 10.0mm from the 6mm that has been put in?

If you pay him to do it, then no. Otherwise, it all comes down to whether or not he became aware of the cooker rating before running the cable.

 

[dx90]

The cooker arrived on the same day as he fitted the cable. He had just fitted the cable when the cooker arrived.

 

[Softus]

He had just fitted the cable when the cooker arrived.

Then I think you should pay him to replace the cable, and I think he shouldn't moan about it.

 

[dx90]

Ok, thanks all for your advice.