Taking a spur off cooker supply

[Hillabaloo]

DIYer question.

I have a 32 amp supply going from consumer unit in garage to kitchen. It supplies an induction hob only. The cable is easily accessible.

I need an additional socket in the garage - 13 amp max. The easiest and hopefully cheapest way to do this is to take a spur off the 32 amp cable.

How should I do this? I will need a junction box and 2.5 mm cable for the 13 amp socket, but how do I do this safely? So for example how can I ensure the 2.5 mm cable is isolated from power going to hob when its on? Recommendations on products would be good also.

Apologies if a daft question.

Thanks in advance.

 

[DPG]

If your consumer unit is in your garage then best to feed the additional socket from there. Don't split the hob feed.

Can you post a photo of the consumer unit.

 

[buzzlightyear]

Post a pic on here before you start, plus could you not extend from the existing socket.

 

[pc1966]

Also remember the circuit has to be RCD protected for sockets, that is another reason for wanting a look at the CU so folks here can advise.

Another factor in England and Wales is new circuits, etc, are notifiable work under Part P of building regulations. It might be far better to see if anyone here work in your area and get it done by someone who is a member of the competent persons schemes like NAPIT, NICEIC, etc, for less hassle and greater safety.

 

[Hillabaloo]

Hi,

Two pics attached. The first shows the consumer unit next to boxed-in services. Directly above this is the living room.

All circuits for the CU go up into garage ceiling void and arent directly accessible. However, the grey cable coming from the CU and through the boxing-in is the hob supply.

The plan is to have a board covering the opening, which will contain modem/router, switch, smart home devices and hide ethernet cable going to rest of house.

Easiest is to take spur from hob supply. Otherwise its taking a spur from garage ring, which would involve a lot more cable/trunking as sockets that are on the ring (and aren't themselves spurs) are on other side of garage..

Most practical solution I think is to tap into the cable thats there. But please advise.

 

[westward10]

So that is in your garage?

 

[buzzlightyear]

Most practical solution I think is to tap into the cable thats there. But please advise.

No, up and down sockets are on the same
Mcb, you should get advice for a spark to put a socket on own circuit in the garage.

 

[buzzlightyear]

Why do Peaple only take half pic, let the farmer see the rabbit. before he shoots it.

 

[davesparks]

How should I do this?

You should not do this.

Leave the dedicated appliance circuit as a dedicated appliance circuit and connect socket outlets to a socket outlet circuit, either an existing one or a new one.

The plan is to have a board covering the opening, which will contain modem/router, switch, smart home devices and hide ethernet cable going to rest of house.

In my opinion this would be better off on its own circuit to reduce the impact from a fault. It would be less than desirable for the Internet connection and network to go off when the hob develops a fault.

 

[Hillabaloo]

So that is in your garage?

yes

 

[Hillabaloo]

Why do Peaple only take half pic, let the farmer see the rabbit. before he shoots it.

I cropped the photos because of size limits on site. The photos had all releavant information.

 

[Hillabaloo]

You should not do this.

Leave the dedicated appliance circuit as a dedicated appliance circuit and connect socket outlets to a socket outlet circuit, either an existing one or a new one.



In my opinion this would be better off on its own circuit to reduce the impact from a fault. It would be less than desirable for the Internet connection and network to go off when the hob develops a fault.

Thanks for this Dave. Not thought that if hob has fault and trips circuit breaker then internet goes off.

But isnt this the case for any circuit?

 

[westward10]

Use the spare way assuming the busbar covers it but if not a new one can be obtained. Simple job for an electrician and they can notify Building Control.

 

[Rockingit]

I’m in Somerset. Drop me a DM if you’d like me to take a look (if you’re in the right part - big county!).

 

[Hillabaloo]

Thanks for this Dave. Not thought that if hob has fault and trips circuit breaker then internet goes off.

But isnt this the case for any circuit?

Also, in a previous property I had a cooker isolation switch with an integrated socket to plug appliances. In essence this is what I want to do, but without the isolation switch. What I dont get is why its OK for the switch and socket but not to do a spur.

 

[westward10]

Also, in a previous property I had a cooker isolation switch with an integrated socket to plug appliances. In essence this is what I want to do, but without the isolation switch. What I dont get is why its OK for the switch and socket but not to do a spur.

I have no idea why you want to do this when there is a spare way, none at all.

 

[Hillabaloo]

I have no idea why you want to do this when there is a spare way, none at all.

(1) I thought I needed an electrician to connect to CU and contact building folks. (2) I wanted to do it myself and keep costs to a minimum. (3) I thought there would be a simple solution given the proximity of the cable to the hob.

I do appreciate your input though.

 

[westward10]

1. Find out the cost.
3. There is a simple solution.

 

[timhoward]

What I dont get is why its OK for the switch and socket but not to do a spur.

Electrically they are different ideas.
In short, reducing cable size half way along a run requires adding extra protection which would be a right pain to implement in this situation. (Wrestling 2 x 6 sq mm wires that aren't quite long enough into a fused spur would be rather torturous)
I wouldn't even entertain doing it this way, when it's such a trivial matter to run it into a new MCB (~£3) in the consumer unit. A simple gland in the side, and off it goes.

I'd imagine you could find a sparks that would let you run the cable and leave a couple of meters of cable for him/her to test, connect, and do the required paperwork.

 

[davesparks]

Also, in a previous property I had a cooker isolation switch with an integrated socket to plug appliances. In essence this is what I want to do, but without the isolation switch. What I dont get is why its OK for the switch and socket but not to do a spur.

The cooker switch incorporating a socket is a bit of a legacy item that we just haven't let go of yet. Years ago a single socket was all you needed for the 1 or maybe 2 small appliances you might have and so it made perfect sense to have that socket built in to the cooker switch. At that point in time the regulations were quite strict about the number of sockets allowed on a circuit.
Since then things have changed somewhat, someone came up with the idea of the ring circuit to feed multiple sockets for a start.

As for why the spur is not OK but the socket in the cooker switch is it is partly down to who you are asking. Most active members of this forum are professional electricians and so our answers are based in regulations, best practice and experience.
We have all experienced the ways in which your proposed spur can cause problems in the future, it could be minor issues like getting shouted at for turning someone's Internet off in the middle of a zoom meeting when you thought you were just turning a cooker off. Or it could be the burned out and melted mess we've had to fix because someone connected a bit of 2.5 into 32A circuit wired in 6mm.

If you ask the same question on a DIY based forum you will likely get a different answer, possibly even a step by step guide on exactly how it could be done (which is not permitted on this forum)

Ultimately would you rather take the advice of professionals who know or have experienced all the ways this could go wrong or the advice of someone who's done it a couple of times before and 'it hasn't gone wrong yet'