Type Of Mains Cable For Alarm

wroenaldinho

Hi All

I'm going to fit a new alarm in a new property I've got which is already wired up to put one in place.

The question i have is in regards to the cable powering the panel.

It appears they have fitted a unswitched fused spur with 13amp fuse in it directly from the fuse box (own circuit stating alarm), which then has some 2.5mm cable hanging out ready to wire in to the panel.

Surely this is overkill and i could swap the 2.5mm cable to something else to power the alarm panel. I'll obviously be taking out the 13amp fuse too and fitting a 3amp fuse.

What cable would be best to use?

Thanks

Robin9

Yes fuse at 3amp but why rewire what has been provided - and doing so may well void your guarantee.

wroenaldinho

There isn't any guarantee as there is no alarm yet. It's just the cable out of the wall. The reason I'm asking is surely an alarm panel doesn't need 2.5mm cable to power it.

unforeseen

But there is no guarantee that it would have only been an alarm connected.

I think IEE regs stipulate the cable that must be used. It makes sense to have normal 2.5 as the electrician will not know that only a low wattage alarm will be connected. Never trust a home owner to stick to the rules where electrics are concerned

wroenaldinho

Its a new build and im the first owner so its been done when built.

The fused spur is fitted with 2.5mm grey cable coming out of it which just needs stripping. To the very left of it there is about 8 white alarm cables hanging out of the wall.

Can i just swap the 2.5mm grey out and use 3 core flex if so what size would you recommend?

Thanks

Grenage

I'd probably use the 2.5mm unless it was going to cause a problem; but with a 3A fuse, I can't see a problem with 1mm cable. I generally don't use flex unless it's going to be moved around (that's what it's designed for).

I am not an electrician.

wroenaldinho

The 2.5mm cable seems like it will be a tight fit to get in the panel.

The instructions for alarm state cable must not be less than 1mm sq.

Think I'll put 1.5mm 3 core flex cable in as the cable will be on show and will look better.

Thanks

stator

Do you have Twin Core and Earth 1.5mm? The type used for lighting circuits.

wroenaldinho

No just the 2.5mm thats hanging out of the fused spur. I was just going to buy 3 core flex 1.5mm and fit a 3amp fuse to spur.

stator

I'm not an electrician but there must be a reason they use twin core and earth, where the earth isn't sleeved. Wheras in flex the earth is sleeved.

unforeseen

wroenaldinho wrote: »

No just the 2.5mm thats hanging out of the fused spur. I was just going to buy 3 core flex 1.5mm and fit a 3amp fuse to spur.

It sounds more like the electrician who only has 2.5 tc with him just used a spare bit as an indicator that the box could be connected to.

Otherwise you are sitting wondering what the fused spur is feeding as it may have all been chased into the wall.

Electricians who are employed to wire houses tend not to carry low power stuff as it isn't required for what they do