PIR Sensor to multiple lights

[Jonny]

Hi all, looking to fit a PIR sensor and any advice would be greatly appreciated.
Senario - an outside corridor has 6 lights, presently on a timer. These 6 lights now need to come on and off by a PIR Sensor.
I have previous experience as an electicians mate and have done odd indoor PIR Systems but looking for some advice and to make sure it's something I can have a look at doing.
As I see things I would use one sensor, positioned in the middle of the corridor, so to detect movement at either end. I'd test the 6 lights to see how they are wired. Hopefully, depending how wired, find the first light with the permanent live and wire the PIR Sensor into that first light. Then use the required length of cable to be able to position the sensor where need.
Could anyone give me any advice on this, where I may have said anything wrong and indeed comment on whether this is something I'd be ok doing. Be much appreciated. Thanks.

 

[Jason S82]

You would need to identify the permenant and the switch wire at the first light and that's if the permenant is there as it might stop at the timer wherever that is and only a load switch wire leaving the timer to the lights

 

[The Ghost]

You need the neutral as well for a ceiling sensor. What is the plan with the switch? remove the switch wire or leave it? How long is the corridor? As different sensors cover different areas length wise. If the lights are in a ceiling grid you could use a four way klix fitting to do what you need. You can get sensors that can be commissioned with a remote (recommended) as it is so much easier. I imagine an emergency light may well figure in that as well?

 

[westward10]

How long is the corridor, you are likely to need motion sensors at both ends or fittings which incorporate motion sensors.

 

[Jonny]

The corridor is about 10 metres long, hence my original thought of just one sensor positioned in the middle of the corridor, with a 10 metre range so that would hopefully detect both ends of the corridor?

I know there is no emergency light there at present.

I have a feeling that the timer for these lights is actually inside the consumer unit, which I've not come across before in my limited experience. Knowing where the lights are and where the cables run from inside I'm hoping the first light should be obvious. Although the guy who has previously done it all seemed to have a strange obsession with JB's!

 

[The Ghost]

The normal round ceiling sensor will cover around 6m so two would do it or you can get a sensor that can cover 25m. Is it singles in conduit or flat gray 6242y? obviously I don't know where this is but I am surprised there is no emergency light. So there is definitely no test switch for that area?

 

[The Ghost]

I'm gonna crack a tube of the amber nectar now, catch you later.

 

[Jonny]

You do right!

Basically it's an outside walkway around 10 metres in length. There are 6 ceiling lights fixed to a wooden roof. He does not want the wooden roofing touching so the sensor and wiring will be surfaced mounted in the neatest possible way. I have no way round that. The cable comes from the fuse box where there is a built in timer at present. I simply have to change the lights from a timer setting to a PIR sensor if I can.

 

[davesparks]

The corridor is about 10 metres long, hence my original thought of just one sensor positioned in the middle of the corridor, with a 10 metre range so that would hopefully detect both ends of the corridor?

I know there is no emergency light there at present.

I have a feeling that the timer for these lights is actually inside the consumer unit, which I've not come across before in my limited experience. Knowing where the lights are and where the cables run from inside I'm hoping the first light should be obvious. Although the guy who has previously done it all seemed to have a strange obsession with JB's!

I'd suggest a little more research into how PIRs work, they basically work on the principle of breaking a beam. So they work best if the movement is at 90degrees to the detector and hardly at all if the movement is directly towards the detector. So one detector in the middle of a corridor will almost certainly not work.

I'm also pretty sure there won't be a permanent live at the first light, there will just be the S/L N and E from the timeswitch.

 

[davesparks]

You do right!

Basically it's an outside walkway around 10 metres in length. There are 6 ceiling lights fixed to a wooden roof. He does not want the wooden roofing touching so the sensor and wiring will be surfaced mounted in the neatest possible way. I have no way round that. The cable comes from the fuse box where there is a built in timer at present. I simply have to change the lights from a timer setting to a PIR sensor if I can.

You are limited in options for surface wiring due to the requirement for fire resistant support. Steel conduit is probably the easiest method.

 

[Jonny]

Yeah I agree on both fronts. We fitted a sensor in a very similar area at the other side of the building and works spot on so although my knowledge at present is limited I'd certainly use the same one again. Because I am left trying to fit this one on my own I was just after any advice on the best way of doing so and what I might need to look out for, if it's something I can do. I'd certainly use the correct conduit etc. If I can't get into this roof area.

 

[davesparks]

Yeah I agree on both fronts. We fitted a sensor in a very similar area at the other side of the building and works spot on so although my knowledge at present is limited I'd certainly use the same one again. Because I am left trying to fit this one on my own I was just after any advice on the best way of doing so and what I might need to look out for, if it's something I can do. I'd certainly use the correct conduit etc. If I can't get into this roof area.

If you are an electrician then yes it is something you can do.
If you are not an electrician then I would suggest that no it is most likely not something you can do as you would not have suitable insurance amongst other things.

 

[Ian1981]

Cp electronics do a microwave sensor at a range of 22 meters max depending on height and width of corridor and comes with optional remote control settings, depends how posh you want to be.