PIR light wiring

[Conmai]

Hello, looking for some guidance on wiring an external PIR light and also having a switch wired for possible maintenance etc...

The plan is:

To fix the PIR light to the wall of the outside toilet
The PIR light has a terminal block inside with a brown, blue and earth wire, run a length of cable from the PIR light to the ceiling light in the toilet to get a LIVE feed
Run a length of cable from the PIR light to the switch

What I'm not sure on is how to connect each of the three wires in the cable I've run from the PIR light to to the toilet ceiling light, the toilet ceiling light is old school, inside it has two cables running into it one for the toilet light switch and one LIVE cable, the two red wires from each cable both seem to be connected together, the two earth cables are also connected together, the black wires from each cable are seperate and are used to connect the light bulb. I'm not sure how these get connected to the cable I've run from the PIR light?

Secondly I'm not sure on what wires get connected together from the PIR light to the light switch I'd like to use?

Hope this makes some sense!

Regards0,

 

[Steve]

Assuming the switch will be for total isolation of the light:

You take the permenant live from the two reds inside the toilet light. You take the neutral from one of the blacks - the one from the mains. The other black is the switched live from the toilet switch.

You run these into a double pole switch (one with L and N connections). A double pole switch is advisable in case the light has a fault which trips any RCD on the lighting circuit.

Then run into the light, so you only have one cable into the light. Most outdoor lights only have space for one cable. You don't want to be wrestling two in.

 

[Conmai]

Hi Steve

Ok, I think I understand;
So only one cable (L,N & Earth) into the PIR unit
The other end of this cable will have its L connected to the Red perm live in the toilet ceiling rose, earth connected to other earths, and the N connected to the black from the perm Live feed (not the black cable from the toilet switch)
The switch I'll use will have a cable running into it, its earth wire connected to the other earths (as above) it's live will be connected to the other LIVES above and its N wire will be connected to the black cable from the perm live feed (same as N for the cable going to the PIR).

One thing I'm considering is putting a modern ceiling rose into the toilet, I guess this would change it slightly?

Regards,

 

[Steve]

You seem to understand the wiring to the ceiling light, but the switch must be in line to the light. So the switch will have two cables to it. The switch has L in and L out, N in, N out. Connect the cables accordingly. This is a double pole switch, usually rated at 20 amps.

By the way I omit the earths from these posts for clarity. You should always ensure earth continuity.

You can change the light for a rose if you wish. Don't do it as part of this job or you may get confused by the wiring along the way. Change the rose, then do this job.

 

[Conmai]

Ok, I think I'm going to replace what I have in the outside toilet with a ceiling rose, I will then run a new length of cable from the PIR light to the ceiling rose, connecting the L to the Loop with the perm Live and the Live from the Toilet bulb switch and the N to the N block in the ceiling rose, I think this will give a functioning PIR light? albeit but not no switch.

I can then focus on the PIR switch that I would also like to hook up, the problem being I can't shake the mental block I have with regards to wiring in a new switch once the ceiling rose and PIR are connected, so with the ceiling rose in place and the new length of cable into the ceiling rose from the PIR light what would be the next steps to wire up a switch? Baby steps will work very well!

Again thanks for your views!

Regards,

Steve

 

[Conmai]

Success of some sorts, new ceiling rose in and PIR light wired In and working, just need to figure out the switch wiring for the PIR, not a nessesaty but would be nice to have...

Cheers

 

[Steve]

Success of some sorts, new ceiling rose in and PIR light wired In and working, just need to figure out the switch wiring for the PIR, not a nessesaty but would be nice to have...

Cheers

Glad to hear.

IN LINE to the new light, you need to interrupt the cable with this:

This is a 20 amp DP switch, you will note it has a live in and live out, as well as a neutral in and neutral out. Other models, with or without neon and engraving are available from B&Q, Wickes and Homebase if you're lucky.

Put this onto a backbox, you'll end up with the cable from the ceiling rose coming in, and the cable to the light going out.

Hope this is clear.

You should use a DP switch because it isolates both poles. In the event of a neutral fault at the outdoor light, this will trip an RCD and you'll have no lights. So by isolating the neutral you'll be able to reset the RCD. Its a remote possibility but better then just switching the live as per a normal switch setup.