Cooker hood and gas hob ignition from single fused spur

[steeve]

Can a cooker hood and gas hob ignition system be supplied via a single fused spur?
I have two separate switched fused spurs fitted to a double backbox. Each has a twin and earth cable connected plus an additional short interconnecting cable which tells me they are wired as part of the ring main. They are currently fitted with 13 amp fuses but I can't imagine these are the rating required.
One spur feeds just the cooker hood and the other feeds just the gas hob ignition.
I would like to fit an extra socket in the vicinity of these spurs without disturbing the tiling. Can I connect both the cooker hood and hob ignition to one of the switched fused spurs to allow me to replace the other by a single switched socket?.

Thanks

 

[ColJack]

err no...

 

[steeve]

err no...

Well that seems pretty definitive.Thanks.


Ok so how about if I remount the two switched fused spurs on new surface mounted boxes in place of the junction box near each appliance where the cables changes to flexible. I could then fit two single switched sockets to the original back box in their place.
The switched fused spurs would be accessible ( but not obviously visible) and fitted to the kitchen units as are the junction boxes at the moment. One would be behind the fascia above the cooker hood and the other on the inside of a base unit next to the hob.
If this is not possible I assume that I can run a short spur from the existing switched fused spur to a new socket position just one tile below.
Thanks

 

[GaryMo]

err no...

Not that I would personally do it that way but if a 3A fuse is fitted with both items being suitably protected then why not?

I'm not sure there's a definitive regulation condoning such practice.
Would the safety of the installation be compromised leading to increased risk to anybody operating the appliances?

 

[ColJack]

314.1 - Every installation shall be divided into circuits, as necesary, to;
( i ) avoid hazards and minimize inconvenience in the event of a fault.
( vi ) prevent the indirect energizing of a circuit intended to be isolated.

314.2 - Seperate circuits shall be provided for parts of the installation which need to be seperately controlled, in such a way that those circuits are not affected be the failure of other circuits, and due account shall be taken of the consequences of the operation of any single protective device.

the single fuse would have to be of a higher rating than the single ones would be to take into account the increased load of both appliances... ( may still be 3A, but it the extract draws 2.6A and the igniter 1A then you'd have to go for a 5A or 13A fuse ( which is what's fitted now.. )).

it also means that to turn the extract off for maintenance etc, you'd also be turning the igniter off..

your second idea seems the best way as it would then be 2 spurs off 2 different points on the ring, and fused / switched individually for each item..

the argument against the regs I've quoted above is that the "installation" stops at the fuse spur, anything connected to the load side isn't classed as part if the "installation"...

537.5.1.3 - In general, all current-using equipment requiring control shall be controlled by an appropriate functional switcing device.
A single functional switching device may control two or more items of equipment intended to operate simultaneously.

this would seem to condone your initial idea since it's reasonable to assume that the cooker hood and hob would be used in conjunction with each other..

 

[Spark123]

An ignitor will only take a few watts, the extractor probably won't run into that high a figure either - a 3A fuse should be plentiful but always check the appliance plates. Have seen the arrangement with both on the same FCU quite a few times, never given it a second thought tbh.

 

[GaryMo]

So nothing definitive against both an igniter and an extractor being fed from the same 3A FCU.

 

[steeve]

Thanks for the help guys, I think I'll go with my second idea. Hardly any extra work or expense and I get two extra sockets.

 

[steeve]

I have kept the ignitor and extractor on separate fused switched spurs which I have moved nearer to the appliances; replacing existing junction boxes.
I have fitted switched sockets to the original backbox in their place.
Everything working ok

Thanks for the advice

 

[ban-all-sheds]

Did you apply for Building Regulations approval before you did it?

Did you test your work?