What size of cable, 6mm or 10mm

[Chris1508]

I'm currently installing a new kitchen and replacing my cooker with a separate hob and double oven.

The hob has a total wattage of 6600 watts and the double oven has a total of 4400 watts

I plan to run a separate cable for each appliance from an isolator switch placed next to the consumer unit.

The cables will run from the isolator switch under the floor for around 6 metres then through a conduit for the last meter to a cooker switch on the wall.

What size of cable should I use, 6mm or 10mm

Thanks in advance, Chris

 

[PrenticeBoyofDerry]

What about the cable running from the CU to the Cooker isolator are running separates for this or just one?

 

[Chris1508]

Because of the way the current cooker cable runs in to the consumer unit I can’t replace it without removing the consumer unit and the board it is attached to and that requires lifting a false floor

Also the kitchen is being re located to a separate area of the house so the old cooker cable will simply be disconnected at the consumer unit and new cable run from a separate isolator switch.

Just as an after thought, I should possibly mention that I plan to use a 50 amp isolator switch and run a cable to each appliance from the isolator switch as combined the power required by both the hob and the oven is 11 KW.

 

[PrenticeBoyofDerry]

I would go with 10mm

 

[Chris1508]

Even though the highest rated appliance is 6.6KW?

 

[RB2004]

couldnt you over rate the cable to the hob isolator switch in the kitchen? then spur off of that to your oven isolator? instead of running 2 separate cables.

wouldnt that save running an extra cable? then both cooking appliances are on the same dedicated circuit.

 

[Chris1508]

Both appliances will be on the one circuit from a 50amp isolator switch but the hob and the oven will have their own separate switches. Also the Hob and oven will be around 2.5 metres away from one and other.

The reason I would like to use 6mm is two fold. Firstly I have recently aquired 25 metres of 6mm T&E saving me a few pennies, hey I'm from scotland and a penny saved ... Secondly and most importantly, I don't want any joins in the wires between the isolator switch and the wall switch for the appliance it's self.

Hope the above makes sense.

 

[Chris1508]

So can I do this safely using 6mm T&E or do I need to use 10mm?

 

[PrenticeBoyofDerry]

If I understand your set up correctly by applying a diversity calculation to the output and assuming the cooker control swithes have no integral socket outlets.
A 45Amp MCB will be need, 6.oomm2 T&E can carry 47Amps safely, providing no derating factor apply such as grouping of cables and the cables does not pass through thermal insulation and the fuse type being used is not a BS 3036.
Hope this helps, but the use of 10mm2 will allow for further upgrades in power at a later date.