What is this please, and can it be used to add an electrical socket in some way?

[WolfOfBakerStreet]

I know it's probably a ''fuse box'' but is obviously different from my main, large fuse box As unlikely as it is, I was hoping it may gave me the option to add an electrical socket. It's the power switch for the boiler, in the boiler room. Many thanks!

 

[ericmark]

It is called a switched fused connection unit (FCU) they are part of the BS1363 range same as a 13 amp socket outlet. One would hope the supply to it has a fuse/MCB/RCBO protection device at the other end, but need to investigate. My boiler is also supplied from one of those, but there is no RCD protection so could not replace with a plug and socket, and it has a limited supply as it comes direct from the solar inverter, so in my case it would need an RCD socket to replace it.

 

[endecotp]

I was hoping it may gave me the option to add an electrical socket. It's the power switch for the boiler, in the boiler room.

Yes, there is a fair chance that you could fit a socket next to that.

Do you know which circuit it is on? Most likely, it’s either on a socket circuit or its on its own circuit. Does your consumer unit have a separate circuit for the boiler? Maybe post a photo of your consumer unit.

 

[Jurassicspark]

What is the rating of the circuit breaker protecting that?

What would the socket, the one you're intending to install, supply?

If its a spur off a ring, with the correct cable size, you could fit a double socket and stick a plug on the boiler cable with an appropriate fuse. Just find a double pole switching socket.

Edit: Determine the cable size to the FCU before doing the above.

The FCU will have a 3A fuse most likely and if you do manage to spur off the load side of the FCU bear in mind that plugging in a loud that exceeds the fuse capacity will cause it to blow and the boiler will turn off.

You can't spur off the supply side of the FCU without investigating what circuit its supplied from and what size is the cable.

 

[securespark]

I know it's probably a ''fuse box'' but is obviously different from my main, large fuse box As unlikely as it is, I was hoping it may gave me the option to add an electrical socket. It's the power switch for the boiler, in the boiler room. Many thanks!
View attachment 393318

Is it still in use?

 

[Ragnar_AT]

Why would the socket need to have a double pole switch? Surely any heating engineer working on the boiler could isolate it safely by simply unplugging it.

 

[SUNRAY]

Why would the socket need to have a double pole switch? Surely any heating engineer working on the boiler could isolate it safely by simply unplugging it.

I'd be happy with a 'double switched socket'

 

[Jurassicspark]

Why would the socket need to have a double pole switch? Surely any heating engineer working on the boiler could isolate it safely by simply unplugging it.

Some can’t be trusted to unplug it.

 

[Jurassicspark]

If its a spur off a ring you could fit a double socket and stick a plug on the boiler cable with an appropriate fuse. Just find a double pole switching socket.

Edit: Determine the cable size to the FCU before doing the above.

@WolfOfBakerStreet Before doing anything, what is the size of the cable supplying the FCU?

If it’s undersized then you wont be able to change the fcu to a socket.

Can we have some pictures, please?

 

[EFLImpudence]

If it’s undersized then you wont be able to change the fcu to a socket.

Why not?

 

[Harry Bloomfield]

It's the power switch for the boiler, in the boiler room.

Aside from the previous comments, worthwhile checking, that the outlet is not controlled/turned on and off, by a thermostat.

 

[Jurassicspark]

Why not?

Who knows the exact size of the flex supplying the boiler?

Switching the FCU to a socket would mean, 1A approximately from the boiler.

Additionally, someone can potentially plug in a high load item, or even worser, multiple high loads causing the cable to overheat, if it’s undersized.

Is it though?

Better safe than sorry

 

[Harry Bloomfield]

Additionally, someone can potentially plug in a high load item, or even worser, multiple high loads causing the cable to overheat, if it’s undersized.

Isn't a fuse/MCB/RCBO specifically required to be installed, to protect the cable from over heating, due to overload?

If it’s undersized then you wont be able to change the fcu to a socket.

The Regulations permit, even a 13amp socket, to be added to a 6amp lighting circuit. Chances are, that boiler circuit will be wired in 1.5mm, protected by a 6amp RCD. The 1.5mm, depending upon installation method, could be rated for 20amps.

The FCU likely has a 5amp 1363 included, because the boiler manufacturer require one, in their installation instructions, despite it likely being even better protected by a 6amp MCB, at the CU.

 

[Jurassicspark]

Isn't a fuse/MCB/RCBO specifically required to be installed, to protect the cable from over heating, due to overload?

Yes, but what if the FCU is spurred off the ring?

The MCB won’t protect that particular cable from overheating.

Chances are, that boiler circuit will be wired in 1.5mm, protected by a 6amp RCD. The 1.5mm, dependingupon installation method, could be rated for 20amps.

I hope so.

If the boiler were to be relocated or removed altogether is it at all reasonable to expect that anyone encountering the socket would immediately infer that it’s supplied via 1.5mm, or conceivably even smaller, cable, and therefore unsuitable for high load usage, absent any explicit indication to that effect?

Assuming if the cable was not in sight too.

 

[Harry Bloomfield]

Yes, but what if the FCU is spurred off the ring?

The MCB won’t protect that particular cable from overheating.

If it were a spur off the ring, that s/would be a 2.5mm cable, it would have a rating between 20 and 27amps. The boiler would be consuming a couple of amps, the maximum for the 13amp socket, a total load of 15amps, as a worst case scenario.

If the boiler were to be relocated or removed altogether is it at all reasonable to expect that anyone encountering the socket would immediately infer that it’s supplied via 1mm, or conceivably even smaller, cable, and therefore unsuitable for high load usage, absent any explicit indication to that effect?

It's unreasonable to assume any such thing, but is always good practice to always check. Perhaps the OP could take the FCU off, and report back?