4 mm Cooker circuit 32amp MCB

[ianphilip007]

just visited a customer who requires a 7.3kw hob connected to replace existing gas hob. Currently has a 2.3kw single oven connected to a 4mm T+E cooker radial (ref method c) Protected by a 32amp MCB

i advised that for the hob to be installed the cooker radial would have to be rewired using 6mm T+E as the 4mm was undersized for the load. but having done the calculations and thought about it I'm not quite sure any thoughts.

7.3kw + 2.3kw = Toal Max Load of 9.6KW = 41.7amps

Diversity applied(no socket at cooker switch) 10A + 30% remainder 10+9.51 = 19.51

with diversity applied Ib <In<It

can't find any reference in the regs to a 4mm cooker radial protected via 32amp MCB as the standard is 6mm/32mcb. Not standard circuit arrangement but as 4mmT+E can carry 37 Amps (ref C) I'm thinking that the additional load may be added.

 

[Essex_]

You keep throwing and we'll keep batting.

 

[ipf]

I would hazard a guess that most don't understand how to do the calculations and just work on a 1.5 = 6/10A. 2.5 radial = 16/20A. 2.5 ring = 32A. Cooker = 6mm & 40A.

4mm radial. Your pulling my leg. No such thing.

Well done IP007 for working it out for yourself.

Well................he has been a member for 3 years... rather more than 3 weeks.

 

[Deleted account]

Thanks for responce.

good to get clarification

Wish I'd never got involved in that debate. It confused me out of doing something I was doing right. But as I say I have future proofed some instals.

Pleased i I joined forum.

 

[Essex_]

Well................he has been a member for 3 years... rather more than 3 weeks.

And that matters why?????

 

[ipf]

And that matters why?????

Maybe one or two do learn from a bit of experience...and don't jump in head first thinking they know it all.

 

[Essex_]

Maybe one or two do learn from a bit of experience...and don't jump in headlong thinking they know it all.

Yes. And I was happy to see that. Fantastic. My other comment was about others not the OP. I think what the OP done was great. I don't understand.

 

[ianphilip007]

thanks for all your input cleared up a mistaken assumption on my part.

 

[telectrix]

Yes. And I was happy to see that. Fantastic. My other comment was about others not the OP. I think what the OP done was great. I don't understand.

never mind. understanding with age you will get.

 

[HandySparks]

...4mm radial. Your pulling my leg. No such thing.

What do you mean?

 

[newtothis]

I'd have to say thanks too. :stooge_curly:
I've been told it's calculate the design current, select the protective device rating, then the cable ?

 

[telectrix]

I'd have to say thanks too. :stooge_curly:
I've been told it's calculate the design current, select the protective device rating, then the cable ?

as long as you get the same answer.

 

[telectrix]

What do you mean?

maybe they don't have 4mm cable in essex.

 

[Essex_]

What do you mean?

You need to read the whole post for it to make sense.

 

[R G]

maybe they don't have 4mm cable in essex.

Remember its not just cables they PULL in Essex Tel..

 

[Essex_]

maybe they don't have 4mm cable in essex.

Yeah. All the northerners keep nicking it for scrap. .....