Socket from Existing Fuse Spur

[doherty1234]

Hello, I am wondering is it ok to wire a socket from inside an existing fuse spur that powers my intruder alarm, Would only be running a router of it & possibly a lamp, Was going to wire in consumer unit but getting a bit tight on space. Thanks in advance

 

[EFLImpudence]

It would be as long as you connect it to the load side of the FCU but it will probably have a 3A fuse in so will not be suitable.

You could wire the new socket from the FCU, putting in a 13A fuse, and then install another FCU with 3A for the alarm.

 

[doherty1234]

If i change to a 13 amp fuse would it be ok to run socket & alarm

 

[EFLImpudence]

Only if the cable to the alarm is capable of carrying more than 13A and the alarm manufacturer does not insist on a 3A fuse.

 

[doherty1234]

probably will not do that then, Is this ok to do.
Wire from existing FCU mains side to a new 13amp FCU then connect load side from new FCU to the socket

 

[EFLImpudence]

No, that would not be allowed.

If there are more than one item on a spur they must limited by a 13A fuse.

 

[JohnW2]

It would be as long as you connect it to the load side of the FCU but it will probably have a 3A fuse in so will not be suitable.

For "a router [I presume a broadband one, not a workshop tool!] and maybe a lamp" (plus the existing alarm) I would have thought that 3A would be sufficient, wouldn't it. I agree that '13A' sockets with upstream 3A fuses do not sound that nice - but they are not unsafe, and I suspect the reason the OP needs 'a 13A socket' is that the router comes with a wallwart.

Kind Regards, John.

 

[Paul_C]

Not strictly permitted according to BS7671, but from the practical point of view simply extending from the supply side of the existing FCU to a single 13A socket is no worse (and in fact could be considered "better") than putting a double socket on an unfused spur, which is permitted.

Some people don't seem to like the idea though:
//www.diynot.com/forums/electrics/multiple-fcus.290867

P.S. Looks like I'm the one who needs to be a little faster tonight John!

 

[EFLImpudence]

I would reply that you may do that if you wish but I don't think it sensible to advise DIYers because it won't be long until someone plugs in the vacuum cleaner and sets off his burglar alarm.

 

[Paul_C]

plugs in the vacuum cleaner and sets off his burglar alarm.

And why would that happen?

 

[EFLImpudence]

I would think it goes off when the power is cut.

Edit - by 'goes off' I meant activates.

 

[Paul_C]

There's usually a battery backup in the alarm panel. But why would plugging a vacuum cleaner into the socket be likely to result in the power being cut? Or more specifically, why do you think it any more likely to happen with this arrangement than with any one of several others?

 

[EFLImpudence]

I thought we were talking about a socket wired through a 3A fuse.

 

[Paul_C]

I thought we were talking about a socket wired through a 3A fuse.

Ah, no. I meant with the socket wired directly to the spur:

Not strictly permitted according to BS7671, but from the practical point of view simply extending from the supply side of the existing FCU to a single 13A socket is no worse (and in fact could be considered "better") than putting a double socket on an unfused spur, which is permitted.

 

[EFLImpudence]

Sorry, talking at crossed purposes between yours and John's posts.