Spur off for a single socket??

Hi, after some advice please. We have a fire alarm in our pantry with a hardwired 5 amp fused connection. Could we take a spur off this for a single electrical socket? Wanted to move a beer fridge into the pantry but have no socket available.
See photos for current set up. Thanks in advance.

It's a intruder alarm isn't it?

Anyway you probably can take a socket from it unless its already spur.

If it has it's own circuit what size mcb/rcbo/fuse is protecting the circuit and does it have rcd protection?

Many thanks for the message. It would seem to be on the same circuit as the sockets in the loft bedroom. It’s on a 32amp fuse. The label below the fuses does say protected by rcd. The fuses on the left which you can see, say not protected.

Per the regs you are only allowed 1 accessory on a spur from a 32A circuit

To get around this you keep the existing spur, change the fuse to 13 A then feed a new fused spur and socket from the new fused spur

I’ll have a go at most things, but that may be a bit beyond me. Any chance you could send me a link to the socket you’re thinking of? Can only find Cooker/ fused switch combos which are obviously way higher rated than needed.

By using the grid switch system, you can have two fuses in a single socket plate, so the feed goes to the 13 amp fuse, this supplies the socket and the other fuse, which in turn feeds the alarm.

I used the Screwfix own brand LAP, the fuse carriers simply click into the front. The better brands, also need a grid plate. Shown here with a fuse, switch and socket using the same idea.

Considering how little current an alarm uses, in practice adding a socket isn’t going to be an issue.

Surprised how many 32A mcbs you have. Hope they have been done correctly. Particularly the loft. And garage.
Does the last socket in the garage have a return cable?

Thanks for the reply. Tbh I have no idea re your question. We’ve had some work done recently which required a sparky who’s very much on the ball and leans towards overkill with safety, so would doubt there’s anything dodgy.

It does seem to be never ending, one thinks the house is up-to-date, and another rule is either changed or clarified, latter is the worst, as it basic says we did not mean this to be read as reported in all the trade publications, what we expected was it to be read as XYZ which is not what electricians thought.

So we thought having two RCD each rated 60 amps was OK with a consumer unit supplied from a 100 amp supply, as the power would be shared between them, but it was clarified that if the supply is 100 amps, then we need to 100 amp rated RCD's.

The problem is we often don't know the size of the DNO fuse, or in other words size of the supply, it could be 60, 80 or 100. And as electricians, we are not allowed to look.

So with an old Wylex fuse box, we know the main isolator is rated 60 amps. So if the DNO has done its job correct, the fuse should be no more than 60 amps, so when we fit a new consumer unit the RCD only needs to be rated 60 amps, but this relies on "if the DNO has done its job correct" and unless there is a sticker on the DNO fuse, how do we know, well I was there when the meter installer removed to fuse to fit a new meter, so I know it is 60 amps, but unless something like that, then we simply don't know.

So I have a consumer unit rated 100 amps, and a 60 amp DNO supply and a 5 kW solar panel inverter, 5 kW = 21.7 amps, so my supply is 81.7 amps, so the DNO should not up-grade my fuse, unless I have a 100 amp fuse fitted before the consumer unit.

So the electrician is often left with a problem, he simply does not know if the home complies, it is not a cut and dried answer so he has to assess the risk, again my house, I can look at my usage and I can see maximum power I normally draw is 6.5 kW or 28 amp, very rare do I exceed that, so if I had a single RCD then looking at the reports over the last year, I can see in real terms no problem, and most people will be in the same boat, so even if it does not technically comply, I see no reason to worry and upgrade.

So 4 x 32 amps = 128 amp, on an 80 amp RCD, but likely a 60 DNO fuse so not a problem, and even if DNO fuse 100 amps, then not likely you would draw maxium except under fault conditions, and fault amps is something completly diffrent.

What may be more to the point, is you have mulitple circuits all on a type AC RCD, and DC can stop a type AC RCD working, however with a type A RCD it is only rated at 6 mA DC, so without any way to see if there is a DC leakage, even a type A can stop working, and 6 mA is not much, so in real terms not worth worrying about, better if each circuit has its own RCD (using RCBO's) but as long as the test button is used every so often, I do it just before clocks change, then the risk is rather low, and not worth worryng about.

I believe 100A domestic supply fuses are sneekly being changed down to 80A, so the max will be 80A in the long term (due to EVs). Your RCD is 80A, so I think you are fine there.

My comment was about seeing a circuit labelled Util. and Loft. Has this really being done as a Ring? or 4mm+ cable ?
Similarly the garage circuit.

AndyPRK said:

My comment was about seeing a circuit labelled Util. and Loft. Has this really being done as a Ring?

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Could be. That's all some know because that's the way it is always done.

Just feed your new socket out the load side of the alarm FCU, it means the new socket will go off when you turn the alarm off at the fcu but I guess you never do that.

Oh unless that's already a spur (I do dislike a ring circuit)

Trouble is the alarm is likely to have a 3A fuse, and the Fridge surge may eventually blow the fuse, leading to cold beer and an alarm going off when the battery has gone flat

Aside from the other points mentioned, the existing RCCB is Type AC. Type A RCD protection should really be considered to be the minimum requirement now (and in fairness most of the rest of the world adopted this position many years ago).

AndyPRK said:

Trouble is the alarm is likely to have a 3A fuse, and the Fridge surge may eventually blow the fuse, leading to cold beer and an alarm going off when the battery has gone flat

Click to expand...

I really should read the whole question, but the 3 amp could be changed to a 13 amp as theres probably another fuse inside the panel.