Adding loft lighting

[geojay]

It’s just occurred to me that as this is in the loft, I can add these lights to the lighting circuit of the floor below. I think this is much simpler than adding it to the ring main.

Looking at https://www.diynot.com/wiki/Electrics:Single-way-lighting# I would be following the “Connecting a single light to an existing lighting circuit. i.e. loft” example although I’d have three fixtures in parallel.

Is there any reason why this would be a bad idea?

Thanks in anticipation

 

[Koolpc]

Please explain what you mean can’t spur from spur from twice. If you mean two radials (spur) from say one point (or one junction box) on the ring and each of those radials runs to a single socket ( or an FCU ) then no. It used to be allowed because it would 2 x 13A fuses but it was discovered that both of those single points might be changed in the future to one twin each so the rule was changed to one single or one twin on one spur (or one FCU) only. Anything after such a fuse would be limited by one 13A fuses (one in a single socket OR one in an FCU OR two in a twin socket - whatever came after those fuses would still be limited by the 13A fuse

Woof?

 

[Ragnar_AT]

In an ideal world you‘d probably put both fused connection units onto the ring instead of running a spur cable to each of them from the socket because that saves you the hassle of having four 2.5 mm2 wires in one socket terminal.

In practice that involves moving one leg of the ring from the socket to the first FCU, then running 2.5 T&E from the first FCU to the second and another length from the second to the existing socket.

You could also get half a metre of 4 mm2 and run that from the socket to the first FCU and from the first to the second.

 

[boringoldcodger]

Is there any reason why this would be a bad idea?

No, its a good idea.
I daresay some of the sparkies will give you some hints. I'd suggest you could use a normal light switch, rather than an SFCU, as you'd be on a lighting circuit which, probably, has a 6Amp circuit breaker in your CU.