cooker hood/extractor and 40a mains spur

[ratbob]

HI, i need to wire in a cooker hood and was going to simply put a 2.5mm twin & earth spur from the back of my 40a/6mm cooker socket.

I would run this 2.5mm to a fused switched fcu. and then flex from this to the cooker hood/extractor fan & light.

My question is: Is this OK to do this and is it safe ? as a lad at work has said you should never spur your cooker circuit?. I cant really see the problem as long as the 40a circuit is not overloaded, currently my cooker is stated 15amp and im not sure of the load on the extractor without rummaging about inside but cant imagine that its above 10amp.

Also I have another extraction fan in the kitchen and was wondering if I could also wire this flex into the same FCU ??

Any comments and expert guidance would be helpful.

thanks. Steve

 

[Chri5]

I wouldn't do it, it's a messy installation method- I'm not sure if you can or can't regs wise, but I'd still not like it.

The 40A circuit is for the cooker and should remain dedicated for it. If you moved, or changed the cooker type the 'spare' capacity you have may no longer be available.
If the cooker switch also has a socket, then that would further drain the capacity when used with a kettle etc.

A fuse spur is designed to allow connection of 1 x device, so connecting 2 is wrong and shouldn't be done.

Take the spurs off the existing ring main and fuse at 3a each.

 

[Space cat]

I cant really see the problem as long as the 40a circuit is not overloaded

You're missing the point. A fuse or breaker protects the wiring that lies beyond it. This means it has to be SMALL enough, not BIG enough. The 40 amp breaker is small enough for the 6 sq mm cooker cable but too big for the 2.5 sq mm cable you want to add to it.

Moreover, as Chri5 says, it's messy. Even if you used 6 sq mm cable to the FCU, it would be an unconventional arrangement that could lead to confusion later.