New Kitchen Circuits

[rsmck]

As part of an ongoing renovation (bought a house with "some internal upgrading required" but we knew what we were in for) we're fitting a new kitchen.

My initial plan was as follows;

30A radial circuit (4mm T&E) for the sockets (4 double sockets) and integrated appliances (washing machine, tumble dryer, dishwasher). The appliances all to be on unswitched sockets with either a grid switch for isolation of each appliance or a single isolator mounted above each appliance.

Separate 10A circuit (not RCD protected) to the Fridge/Freezer (the CU is on the wall that backs onto the kitchen so this is easy to achieve and should minimise nuisance trips - the cable can be entirely surface run (not buried within plaster) so does not require RCD protection per the 17th Edition regs.

I'm looking for opinions on how best to do the cooker circuit - we have a hob which can theoretically draw 20A, and a cooker rated around 15A - my intention was to run both of these off a 45A cooker control unit served by a 40A MCB (6mm cable) with H05RR-F cables from the cooker connection unit to both the cooker and the hob - firstly is this acceptable or should I only have one device connected to the cooker connection unit. Secondly, we now also are apparently having a built-in microwave, would it be acceptable to run this from the same cooker control unit (3 devices, one switch) or should I just add another socket as planned for the other appliances (with an isolator)

p.s. in Scotland so Part P does not apply.

 

[i=p/u]

just add extra socket outlet for microwave postion and yes you can feed both hob and oven off one switch if you can get 2x6mm to fit???

with diversity you could drop to 20Amcb and use 2.5mm providing your calculations are correct. but you aint future proofing, but you might not want too

 

[Electricalserv]

Why do people use 4mm radials when its unlikely not needed. o.k above 50m2 yeh but some just use it unnessesarily.

 

[i=p/u]

profit down the drain electricalserv,,,aaaaa

 

[rsmck]

Aiming to future-proof - plus it wouldn't be the first time in our previous home we've had all hobs on + the cooker so downrating to 20A is probably pushing it and I wont be popular if it trips when my better half is preparing something for guests

 

[rsmck]

Why do people use 4mm radials when its unlikely not needed. o.k above 50m2 yeh but some just use it unnessesarily.

It's not above 50m2 (wish i had a kitchen that big ) - I just wanted to ensure there was enough to handle the load the kitchen *may* throw at it (the appliances, kettle, coffee machine etc) along with future-proofing, so would rather use 4mm than 2.5 which would limit the circuit to 20A.

As for radial vs ring final on 2.5mm - that's just a personal preference

 

[Electricalserv]

It's not above 50m2 (wish i had a kitchen that big ) - I just wanted to ensure there was enough to handle the load the kitchen *may* throw at it (the appliances, kettle, coffee machine etc) along with future-proofing, so would rather use 4mm than 2.5 which would limit the circuit to 20A.

As for radial vs ring final on 2.5mm - that's just a personal preference

You can split it into 2 radials. 4mm cable is a nightmare to terminate at times. Even better put it on a ring! I had a kitchen fitter ask me to come and do some day rate work with him this week. He was putting 2 4mm radials for up & down sockets. I don't know whether he was trying to sound clever but I just laughed and went along with it.

 

[rsmck]

Thanks electricalserv - I might just do that, there's plenty of spare ways in the consumer unit - one 2.5mm radial for the counter-top circuits and another for the appliances would make sense and I've got loads of 2.5mm T&E lying around whereas I have no 4mm (!)

 

[anton1210]

why not just turn the 2 radials into a ring? less work, and 32A instead of 20A. i believe the socket for the fridge/freezer has to be labeled as fridge/freezer as it is not RCD protected.