Connect gas hob ignition to cooker circuit

Thierry

Hi,

I have a new extension built for my kitchen and I have a gas hob recently installed by the plumber.

I plan to add an electrical oven (under counter) and connect it to the cooker switch installed over the counter by the electrician (private circuit).

I have not used the electrical ignition for the hob yet as I am not 100% sure how to connect it to the mains. The cable from the gas hob is left with the 3 wires all out.

There is a cable running from the cooker switch but it is ended with a temporary grey box.

Now my question is, how would I connect the electric cooker and the gas hob ignition to the mains?
Can I use the same source from the cooker switch, and just replace the temporary grey box with a double socket?
If yes, should the double socket be fused, and where should I place it?

Thanks for your help.

Red Alert

You would be better off connecting to a 3-amp fused spur, ignition circuits use almost no power.

Carlow52

Red Alert wrote: »

You would be better off connecting to a 3-amp fused spur, ignition circuits use almost no power.

+1 as the cooker cable will be on a 32A mcb so the double socket idea is a no no

ntpm

Carlow52 wrote: »

+1 as the cooker cable will be on a 32A mcb so the double socket idea is a no no

Quite right.

Some under counter ovens can operate from a 20Amp Circuit. ie from a dedicated radial socket circuit or kitchen ring circuit... however check electrical load of heaters.
If you do use the cooker switch via the grey connector, the 32Amp MCB in the fuse board will be too big to protect the cable therefore I would suggest that you reduce it to 20Amp MCB then you could put a double socket or fused switch spurs on the end of it.
The Hob ignition could also be pluged in the the socket but put a 3 Amp fuse in the plug top.

Thierry

ntpm wrote: »

1 "... however check electrical load of heaters...."

2 "If you do use the cooker switch via the grey connector, the 32Amp MCB in the fuse board will be too big to protect the cable"


3 "The Hob ignition could also be pluged in the the socket but put a 3 Amp fuse in the plug top."

1- no electrical heaters, all central gas.

2- I am not 100% sure to understand: is it the cable from the oven that needs to be protected?
The other cables, from the fuse board to the cooker switch and pass the cooker switch are all the same type: squarish grey cables, so they would be protected from the radial cooker circuit MCB.

3- Got you there. So I just need to protect the cable from hob with a 3amp plug. Could I do the same with the oven cable: just plug it with a 13A fuse(or more?) to the double socket or some little fuse board?

The cable running from the switch is buried behind the plaster board and dry lining, to come under the countertop. From it I can then plug a fused junction or a double socket, with appropriate fuses to connect the hob (3A) and the Oven (13A)?

Thanks

Buford T Justice

Thierry wrote: »

The cable running from the switch is buried behind the plaster board and dry lining, to come under the countertop. From it I can then plug a fused junction or a double socket, with appropriate fuses to connect the hob (3A) and the Oven (13A)?

Thanks

As posted above, double socket is a no no. You can fit a junction box under the counter and put the 6 Square (cooker cable) into that, and use more of the same cable to go into the back of the oven. From the junction box you can fit a fused spur and put the hob ignition into that.. Make sure the JB is rated for at least 32A, as that's what will be on the MCB

ntpm

Fingers McGee wrote: »

As posted above, double socket is a no no. You can fit a junction box under the counter and put the 6 Square (cooker cable) into that, and use more of the same cable to go into the back of the oven. From the junction box you can fit a fused spur and put the hob ignition into that.. Make sure the JB is rated for at least 32A, as that's what will be on the MCB

Thierry and Fingers McGee.
I am refering to the dedicated cooker cable circuit (32 amp MCB).

The principle, as i understood it, The Cooker 32 Amp MCB is to protect the cable from possible overloading, overheating and burning.
The cable run is from the fuseboard via the switch through the wall and onto the appliance ( or in this case to the junction Box) .
It is not there to protect the appliance or the user.
Therefore if you reduce/ de-rate the 32A to a 20A MCB you can install a socket on to it and this is acceptable.

Also Thierry,
I meant the electric heaters in the under counter oven ( this info is available from the manufacturer/ supplier).

Solair

A gas cooker's electrical requirements for an igniter and any timers / clocks or electronics are no different from the requirements of any small appliance e.g. your bedside clock-radio.

It should be connected to a normal socket circuit (protected by an RCD), either via a plug, with a 3 amp fuse fitted, or via a switched fused spur unit. Either way, this should be accessible so that you can disconnect the cooker when you are cleaning it or if it requires maintenance.

You don't need dedicated cooker circuits, i.e. the same as an electric cooker.

Irish wiring rules don't allow you to connect appliances, other than an electric cooker, to cooker circuits. This is why we haven't had those combined cooker switch + socket units which were popular in the 1970s and 80s in recent years even though they remained in use in the UK.

So, basically just treat your gas cooker as if it were a normal appliance, and connect it to an RCD protected socket circuit (but never directly i.e. it MUST go via a plug or a fused switched connector unit.)

Red Alert

Even when I was a kid I wondered if that socket was really just in parallel with the cooker switch. Seemed odd to allow it.

2011

This is why we haven't had those combined cooker switch + socket units which were popular in the 1970s and 80s in recent years even though they remained in use in the UK.

...and because this socket would not be protected by an RCD.

byte

Red Alert wrote: »

Even when I was a kid I wondered if that socket was really just in parallel with the cooker switch. Seemed odd to allow it.

My parents house had one. The one 6sq? cable just fed it. It's probably a good job you can't get them anymore!

Solair

Ireland's required RCD protection on socket circuits for much longer than the UK has. In fact, I think it only became a requirement over there in the most recent revision of their wiring rules.

The logic of the socket on the cooker switch was that in old installations, the only appliance in the kitchen was a kettle and maybe, if you were really posh, a toaster

To save cost and copper, they included a socket on the cooker control switch. Because BS1363 plugs contained fuses, it was assumed that adequate overcurrent protection was provided by the fuse, much like it would be if the socket were on a ring circuit.

The RCD requirement in Ireland eliminated that arrangement as cooker circuits were exempt from the requirement for RCD protection.

I've never thought it was a particularly good practice as it often encouraged inadequate provision of sockets in kitchens in the past and encourage people to locate their kettle and trailing flexes way too close to the cooker's hot surfaces. E.g. it wasn't unusual to see things like the cooker control - socket located OVER the cooker!

You have to remember that the BS1363 fused plug and ring circuit system was introduced in the UK after WWII and its main aim was to reduce the amount of copper being used for wiring houses. There was a vast amount of new housing going up and there was a serious crisis in the supply of copper at the time too. People also had far less disposable income than they do today (even in the credit crunch), so costs had to be minimised. It was generally a *much* poorer society.

Some experimentation was done with using aluminum wiring too in some countries which proved to be generally disastrous as it was prone to cracking / breaking and caused house fires.

M cebee

Solair wrote: »

Ireland's required RCD protection on socket circuits for much longer than the UK has. In fact, I think it only became a requirement over there in the most recent revision of their wiring rules.

The logic of the socket on the cooker switch was that in old installations, the only appliance in the kitchen was a kettle and maybe, if you were really posh, a toaster

To save cost and copper, they included a socket on the cooker control switch. Because BS1363 plugs contained fuses, it was assumed that adequate overcurrent protection was provided by the fuse, much like it would be if the socket were on a ring circuit.

The RCD requirement in Ireland eliminated that arrangement as cooker circuits were exempt from the requirement for RCD protection.

I've never thought it was a particularly good practice as it often encouraged inadequate provision of sockets in kitchens in the past and encourage people to locate their kettle and trailing flexes way too close to the cooker's hot surfaces. E.g. it wasn't unusual to see things like the cooker control - socket located OVER the cooker!

You have to remember that the BS1363 fused plug and ring circuit system was introduced in the UK after WWII and its main aim was to reduce the amount of copper being used for wiring houses. There was a vast amount of new housing going up and there was a serious crisis in the supply of copper at the time too. People also had far less disposable income than they do today (even in the credit crunch), so costs had to be minimised. It was generally a *much* poorer society.

Some experimentation was done with using aluminum wiring too in some countries which proved to be generally disastrous as it was prone to cracking / breaking and caused house fires.

the UK has leapfrogged us in some respects -they've introduced rcd protection for cables buried less than 50mm

in terms of socket outlets -they have more exceptions-such as sockets under the supervision of skilled persons don't require rcd protection


all circuits 30mA protected is common now for domestic-in the uk

Bruthal

Its amazing when you think of it, the cooker circuit is protected by a 32amp MCB, and people will say its not there to protect the appliance just the cable, well that may well be the theory, and what we are told as apprentices, and in cases where there is a fused outlet at the end of the cable it is true, but in the event of a short inside the cooker if an electric hob, or the oven, what protects that then?

In appliances like cookers the MCB does offer protection to the appliance itself, even though the MCB is sized for the cooker cable. And the cooker has 2.5 square wiring in it with nothing except the 32 amp breaker behind it so that wiring is under rated technically.

At the time sockets were removed from cooker switches, there was no reason to remove them except for the RCD reason as i think 2011 mentioned. After all, ring mains were a 5 square circuit with a 32amp breaker right up until very recently.

Thierry

Solair wrote: »

So, basically just treat your gas cooker as if it were a normal appliance, and connect it to an RCD protected socket circuit (but never directly i.e. it MUST go via a plug or a fused switched connector unit.)

Thanks for all the info guys!

I am going to follow Solair advice and just plug the cooker into the MCB cooker switch!

Now my problem remains. How do I plug the cable from the gas hob ignition?

There is a double socket over the counter for toaster and kettle! but can I have the hob cable running so close to gas fire, not to mention the esthetics!

So I would better have to run it under the counter to the next double-socket under counter, where dishwasher is plugged, 2.5 meters away!
As the cable is too short to reach this socket I am thinking of using a junction box to connect the gas hob and a fused plug with a 2.5 meters wire.
Would that be alright?

Thanks
Thierry

Buford T Justice

Install a fused spur off the cooker cable and wire it in there. much simpler

Solair

Fingers McGee wrote: »

Install a fused spur off the cooker cable and wire it in there. much simpler

Is that allowed though without an RCD ?

You could always get an RCD switch spur

2011

Is that allowed though without an RCD ?

Yes. You are permitted to supply a fixed appliance such as this without using an RCD.