Kitchen Rewire

[russellellwood]

I had three people round on friday to price up installing a kitchen ring main for me. Two of them said they would install new 2.5mm cable and sockets with the dishwasher, fridge freezer, waste disposal and extractor spurred off the ring. The other guy said he would install 2.5mm cable for the ring(sockets only) and then use a 16A MCB for dishwasher and extractor and another 16A MCB for fridge/freezer and waste disposal.

Which one of these would be the better install?

Cheers

 

[kevindgas]

without a doubt no.3 is the better install as he is providing seperate lines for the higher powered appliances

but so long as the correct tests are carried out then any of the 3 would be ok
I'm assuming there is spare ways on your consumer unit for the seperate circuits?

 

[russellellwood]

I should of said the work quoated for inclueds a new consumer unit, with the list of specs he left the new cu is a wylex 10 way dual rcd board, with 3 x 6a, 2 x 16a, 4 x 32a, 1 x 40a.

the 4 x 32A he has down for upstairs ring, down stiars ring, kitchen ring and utility room ring.

So i think this is why he suggested the 16A radial for the appliance.

For the 16A radial he had down 2.5mm twin and earth, from what i have read should this not be 4mm?

Cheers

 

[rebuke]

In general 2.5mm is fine for a 16A radial, you could probably even do a 20A one (derating factors might make it not work, but in most normal situations it's fine).

 

[sparkyspike]

The first two methods are fine, providing each appliance is on its own fused spur. The 3rd method is definitely better, as it anticipates using many appliances at once.

In addition to running high loads (such as the dishwasher) on a radial, I would recommend running fridges and freezers not only on their own radial as planned, but also on their own RCD. This will isolate your fridge from the communal RCD and will protect the fridge from defrosting due to an earth fault elsewhere. You will need to have a slightly larger board fitted, with a spare way or two next to the main isolator which allows you to fit a combined RCD/MCB for the fridge (known as an RCBO). It won't make a drastic difference to the price - £50 maybe - and it's no problem to fit, so ask your electrician about this.

 

[russellellwood]

Many thanks all for your help, will speak to him tomorrow about the rcbo. Once again thanks for the help.