Adding External PIR

[Rekusu]

Hi there,

My question is very similar to other recent threads and I'm trying to get my head around a simple concept.

I have a new build house with a light on either side of the front door, operated by a single, internal, three gang switch (three gang because the switch controls two other internal lights.) Foolishly, I did not include a PIR beside the front door and would like to add one.

Each light only has a single, twin + earth and the relevant switch has three twin + earth. Presumably, one is the switched live?

The PIR would only be about 3 cms below one of the lights. The PIR I would like is: http://www.timeguard.com/products/l...0-surface-mount-ceiling-pir-presence-detector

I'm quite able to actually wire it up safely, but really need some advice as to how.

Thanks

Rex

 

[Taylortwocities]

That PIR is designed to be mounted above your head (e.g. the ceiling of the porch). It will not work mounted on the wall! That is why it is called a ceiling surface mount PIR presence detector.

You need something like this http://www.tlc-direct.co.uk/Products/SS6015.html

 

[AndyPRK]

That's bad news if each light only has 1 cable.

 

[JohnW2]

Each light only has a single, twin + earth and the relevant switch has three twin + earth. Presumably, one is the switched live?

Could you perhaps explain that in a little more detail?

Kind Regards, John

 

[Rekusu]

//media.diynot.com/139000_138858_81878_57892074_thumb.jpg

Not sure how to add an image to the forum but have tried. If it succeeds, the image is the back of the switch; the red circles are the 1Way and COM connections for the external front door lights.

On each of the lights, there is only a single twin and earth.

Hope that is clearer.

Rex [/img]

 

[AndyPRK]

Lol. Someone's put sleeving on the switched wires.
That's teaching by numbers.

 

[Rekusu]

Not sure what your comment implies, but that is what the sparkie did when the house was wired up. The BCO did not inspect every switch but did have a look behind the CU and was more than happy with how neat it looked.

In terms of me wanting to put an external PIR, what should I be looking at?

 

[AndyPRK]

It's not easy to fit one pir to control 2 lights in your case.
Unless you can fit a cable between the lights.

 

[Rekusu]

Probably not what I wanted to hear but if that is the case, so be it.

There is almost no chance of running a cable between the two lights as we not only have glass side panels on with side of the door, but also a 1.5m high glass panel above the door.

 

[AndyPRK]

I guess your options are

1. Fit a pir below each light.

2. Change lights to lights with built in pir.

 

[EFLImpudence]

I'm a bit puzzled.

There are several blue wires behind the switch which are likely to be neutrals.

If this is the case then, surely, only a new cable (3C+E) from the switch to the PIR would be required.

 

[Rekusu]

You will see from my posting that I am not an electrician!

This three gang switch operates the two external lights (circled) and two internal entrance lights. There are six 2c+e cables coming into the box.

All the browns are as you see in the image (sorry it's so small); the blues are all into a choc-block as are the earth.

It may not be technically correct, but as I said, a qualified sparkie did the job, as he had to sign off the electrics on a new build. It does work as it should; I would just like the addition of an external PIR.

I don't really want to change the lights as they are part of the house 'design.' I have other similar lights on the outside.

 

[EFLImpudence]

Can you run a cable to a suitable position for the PIR or

can you run another cable to one of the light positions and have the PIR there (near the light)?

 

[Taylortwocities]

This is how you upload the photo so it is displayed in your posts
//www.diynot.com/forums/viewtopic.php?t=129539

Looking (again) at your switch wiring, the only option would be for you to run a new 3-core and earth cable from the switch to a place where a PIR could be fitted.

 

[AndyPRK]

Yes it's a good point assuming a DIYer is capable of running a cable between the switch and pir.