Loop at ceiling. Not a great idea?

[Jupiter01]

Can I get your thoughts on this please.
I’ve always understood that both, loop at ceiling or loop at switch are valid approaches for lighting circuits. I’ve always looped ceiling as it’s the approach I first learnt. I’m now beginning to question its usefulness for these reasons:

- in a single room I was wiring 3 separate lights and the loop at ceiling method meant that a live cable needed to be run to each lighting point. I can’t help but feel that I used much more cable than I needed to.

- some of the light points have 4 cables: live in, live out, power to a connected light and switch. This is going to require a light fitting that allows me to squeeze all of these cables in. Will limit my choice for a light fitting.

- in the recent past, I used the Shelly devices to remotely control my lights. This requires a permanent neutral and hence, would also need to go in the light fitting I.e. require further space.

I am now wondering whether loop at switch is really the only way to go. Will appreciate your thoughts on this.

 

[sparkwright]

The loop-in at rose method is dead now - nowadays it's old fashioned, and seriously buggers us up when installing downlights or fancy fittings. As you say, neutrals are sometimes required for special switches.

The only time I now use the loop-in at rose method is on old houses being re-wired where they are not redecorating, and where old switch conduits can be re-used.

 

[securespark]

I use the loop at switch method.

BUT.......in cases where I need a permanent live in the ceiling, I will take a 3 core up from the switch.

Examples could be for a smoke detector or a live feed to another point.

 

[ericmark]

Loop at ceiling rose allows use of fan or emergency lights at the ceiling rose, and gives a better loop impedance, however the drops to the switch form a capacitive and inductive link which was OK with tungsten lamps, but not so good with LED.

The use of the relay at the ceiling rose can give best of both meaning the drops to switch are extra low voltage and you can use smart switching in the same way as a two way switch, so both wall and phone can turn lights on/off when required, although small it is too big to fit inside a ceiling rose.

I know Hager Klik do a 4 pin plug in ceiling rose P64AX/R which allows one to take un-switched power from the rose for emergency lights etc, but I question is a plug in ceiling rose any better than these should we take power for other than lights from the ceiling rose?

Since we are in the main limited to 6 amp due to ceiling roses and other junction boxes and switches only being rated at 6 amp we can use around 44 meters of 1.5 mm² and stay within the 3% volt drop.

I know LED lamps do not suffer in same way as fluorescent lamps with volt drop, and likely we can get away with more, but have you ever measured the volt drop on lights? Assuming a loop impedance of 0.35 Ω on the in coming supply we should have no lower than 1.81 Ω at the ceiling roses between lives (line and neutral) I have not personally checked in resent years need some thing like the plugs shown into a socket to match loop impedance tester to do the test, and I never bothered to make one up.

But I know how easy it was to exceed the 88 meters, now 106 meters for sockets, so can one wire a house with less than 44 meters of cable for lights? Down to 29 meters with 1 mm² which would be very easy to exceed.

So with volt drop considerations I think loop at ceiling rose is the only way with larger homes.