Big cooker

[del6842]

The wife has just ordered a new electric cooker on checking the spec it says its total load is 14.5 Kw . The length of cable run from consumer unit to cooker is 10m. The consumer unit is a split box with 100A main switch 2x32A 2x6A 1x20A 1x40A with 6mm cable to the old cooker. I propose to fit 16mm cable in conduit and a 50A mcb is this ok any comments would be helpful.

 

[davy_owen_88]

16mm will do fine for full load but the 50A MCB will not:
14500W/230V = 63.04A

Cooker diversity:

10A + 30% of remaining + 5A for socket
10A + 15.9A + 5A = 30.9A diversified load

So for your 10m run 6mm^2 on a 32A MCB will be sufficient.

You might want to check whether the cooker has terminals for 2 radials (oven + hob) as running a second 6mm^2 radial will be cheaper than ripping out the old and replacing with 16mm^2. (£2 vs. £5 per metre)

Davy

 

[JohnD]

Try to persuade her to change it to one with gas burners on the hob. they're much better.

 

[del6842]

Thanks for the help. the fuse board is a new Volex and the biggest mcb that they make is a 50A or should i go for a different manufacturers mcb if any make more than 50A (also the cooker isolation switch from most manufactures is 45A ( i know it is not going to be switched on and off under load ) is this o.k any suggestions.

 

[davy_owen_88]

I wouldn't mix MCB's from different manufacturers if you can help it. As you said you won't get a cooker switch rated at more then 45A so you couldn't use it anyway.

You shouldn't fit an MCB with a rating higher than that of the lowest rated fitting/cable connected to it. As I said in my previous post, after diversity your current MCB and cable will be sufficient so you don't really need to upgrade anything.

You might want to check whether the cooker has terminals for 2 radials (oven + hob) as running a second 6mm^2 radial will be cheaper than ripping out the old and replacing with 16mm^2. (£20 vs. £50)

Davy

 

[securespark]

Most CU manfacturers do not sanction fitting more than one breaker of >40A.