changing/extending a unused cooker radial

[stewall]

can any one help?

i am currently installing an new kitchen and i am using a complete new lay out. so this means that most of the sockets are not in the positions where they are needed-these sockets are supplyed by the main ring. there is a cooker socket which is wired on its own 4mm radial circuit with i believe a 32mm replacable fuse in the consumer unit.

now i want to take away the cooker socket as we use gas anyway so there is no need for it and extend the circuit with 2.5mm wire and have 4 sockets on it(supplying a fidge,microwave,washing machine and a kettle.

is this safe to do so and what fuse will i need in the consumer unit?

 

[Big_Spark]

can any one help?

i am currently installing an new kitchen and i am using a complete new lay out. so this means that most of the sockets are not in the positions where they are needed-these sockets are supplyed by the main ring. there is a cooker socket which is wired on its own 4mm radial circuit with i believe a 32mm replacable fuse in the consumer unit.

now i want to take away the cooker socket as we use gas anyway so there is no need for it and extend the circuit with 2.5mm wire and have 4 sockets on it(supplying a fidge,microwave,washing machine and a kettle.

is this safe to do so and what fuse will i need in the consumer unit?

Yes you can do this, however where the cooker point is at the moment I would suggest you install a Fused Spur (FCU), this need no be switched. The Input cable being the 4mm2 and the output side being 2.5mm2. Then you would run the circuit from that. The Consumer Unit fuse/MCB should be no more than 20A, ideally only 16A.

One alternative would be to wire the additional sockets in 4mm2 cable, that way you will not need the FCU and can simply make the former cooker point a socket..single or double depending on the box the CCU was in and your personal choice.

If you do this then the circuit breaker for the radial can actually be a 25A MCB, better still would be a 25A 100mA RCBO.

Hope this helps.

 

[securespark]

But aren't we then into the realms of multiple socket outlets fused down to 13 Amps, which is against every fibre of your being, FWL????

 

[ban-all-sheds]

But aren't we then into the realms of multiple socket outlets fused down to 13 Amps, which is against every fibre of your being, FWL????

Aahhh - leave it alone - he was in a good mood today....

I was going to suggest an FCU, but I thought no - I'll let someone else take the flak for that, as I've got something else to possibly argue about with him....

 

[Big_Spark]

I agree that multiple sockets from a 13A FCU are not ideal, but as the supply cable and the new cable are of different sizes then you MUST fuse it down, there is no other way around this problem, except the second way of doing this and woring the Radial in 4mm2 along it's length.

So Ban, what other argument you got?

 

[il78]

Bet ya' he mentions the 100mA RCBO.......

 

[Big_Spark]

Bet ya' he mentions the 100mA RCBO.......

Thats a good bet, but as some fridges and freezers trip 30mA, 100mA id the best compromise between practical safety and functionality.

 

[il78]

But it dont provide supplementary protection for equipment bein used outdoors.......

 

[Big_Spark]

But it dont provide supplementary protection for equipment bein used outdoors.......

I can read that two ways...

One way would be to say..why should it provide thisa protection as there is no indication it will be used for this purpose?

The other way is to say: You obviously feel there is no requirment for the RCD on this circuit as it will not provide power to externally used appliances, however two things spring to mind straight away. Firstly, whilst this is not the intention, it could never be rulled out as a possibility. The circuit exists in a Kitchen which is an inherently more hazardous area than any other part of the house, except the bathroom, and thus should be afforded a greater degree of protection than other circuits.

I do not advocate using RCBO's or RCD's to protect every Ring or Radial in a house, one must look at the potential use of the circuit before deciding on the protective device, however where this changes is in Kitchens, here I advocate the use of RCBO's to protect rings and radials due to the increased risk you find there. This is not a requirement of BS7671, just a personal choice for increased safety. I do recognise that some devices will cause nuisance tripping in 30mA RCD's/RCBO's, consequently I tend to advocate 100mA trips on circuits certain to provide power to such appliances.