Security lights from fused spur in loft

[SFK]

Note that I am a DIYer, (so happy for John to correct me)

I think you also need:
A white back box to put your DP switch in:
https://www.screwfix.com/c/electric...m_sp=managedredirect-_-electrical-_-1gbackbox

If your DP switch has a fuse, then change this from a 13A fuse to a 5A fuse.

Presuming that your cable will be outside and exposed to sunlight/UV I would use the following 0.75mm2 cable between the lamps:
https://www.screwfix.com/c/electric...de=3183p&conductorarea=0_75_mm_&sort_by=price

cable clips (above 0.75mm2 cable has a 6.8mm diameter):
https://www.screwfix.com/p/tower-co-axial-cable-clip-7-0mm-black-pack-of-100/14161

You also need to consider how to join the cables and the lamp at the security lamp themselves. Does the lamp have an internal area for this? Or simple a length of cable sticking out of the back?

 

[JohnW2]

John , Agreed, not sure why/how but I once manged to get a SP version (possibly becuase I used to buy the cheapest version/brand), and have ever since always double checked to make sure DP.

Decades ago, SP ones did exist (and I may even have some lying around somewhere), but I haven't seen one for many years.

Having said that, before I install any switch I usually check its functioning with a meter - and I did, once, many moons ago, come across a DP switch (can't remember whether it was in an FCU or what) in which one of the poles was 'jammed closed' (can't remember whether it was L or N) - something which would, of course, probably not have been detected if I hadn't checked.

Kind Regards, John

 

[JohnW2]

Note that I am a DIYer, (so happy for John to correct me)

I'm also a DIYer, but, for what it's worth, I don't disagree with anything that you go on to say!

Kind Regards, John

 

[Minime46]

Note that I am a DIYer, (so happy for John to correct me)

I think you also need:
A white back box to put your DP switch in:
https://www.screwfix.com/c/electric...m_sp=managedredirect-_-electrical-_-1gbackbox

Presuming that your cable will be outside and exposed to sunlight/UV I would use the following 0.75mm2 cable between the lamps:
https://www.screwfix.com/c/electric...de=3183p&conductorarea=0_75_mm_&sort_by=price

cable clips (above 0.75mm2 cable has a 6.8mm diameter):
https://www.screwfix.com/p/tower-co-axial-cable-clip-7-0mm-black-pack-of-100/14161

You also need to consider how to join the cables and the lamp at the security lamp themselves. Does the lamp have an internal area for this on simple a length of cable sticking out of the back?

I havent picked the lights yet but if need be I will get external junction boxes. I also want to hook up PIR sensors.

 

[winston1]

You don’t need a fused spur and they should not be used on a lighting circuit. A 3a fuse will have no discrimination against a 6a MCB. Use a double pole switch.
Some people will argue a FCU is cheaper. That is a cowboys answer. In the scheme of things the additional cost of using the correct component is not significant.

 

[JohnW2]

You don’t need a fused spur and they should not be used on a lighting circuit.

Not "should not" but, rather, "need not" (and won't serve a particularly useful purpose if they are used).

Some people will argue a FCU is cheaper. That is a cowboys answer.

.. in which case I have no problem with being regarded as a cowboy.

 

[DetlefSchmitz]

You don’t need a fused spur and they should not be used on a lighting circuit.

In your personal opinion

Use a double pole switch.Some people will argue a FCU is cheaper. That is a cowboys answer.

In your personal opinion

 

[winston1]

In your personal opinion
In your personal opinion

Please explain why you think a FCU is needed on a lighting circuit.

Please explain why you think anyone other than a “cowboy” would suggest using an incorrect component just because it is very slightly cheaper.