Wiring question - interior lighting - PIR-activated

[Allen]

Hi there, I want to have PIR-activated lights in my hall and landing. In the past, I have used PIRs which are specially designed to replace an ordinary wall light switch, screwed directly into the switch housing. Trouble is, they cost at least £25 each, and they don't last long. So now I am thinking of buying two of those rectangular wall-mounted lights with built-in PIR, designed for exterior use, like they sell at B&Q. I plan to remove the wall light switch, and use the wires inside to feed the lamp, fixing the lamp over the switch housing. Can anyone see any problem with doing this?

Thank you

Allen

[Andrew Gabriel]

You won't normally have a live and neutral connection there, but a live and switched live connection. It would be easy to modify the loop-in connections (on the ceiling where existing light is presumably) to change the cable to the switch to be a permanent live and neutral supply.

[BillR]

It will look extremely naff and amateurish...

[Mungo Henning]

Just fitted one of these for a friend today (12.99 at Screwfix). Nice unit - perfect for the end of a garage, but I wouldn't fit this inside a house.

Why not buy a standalone PIR and wire this in to switch the lights? These can be bought from Screwfix too (I have no connection with Screwfix, apart from being a reasonably happy customer).

I always try and fit a standalone PIR just so that I can keep the light and what triggers it as separate units. The slight hope is that Bob the Burgler doesn't see that the light has been triggered by a device and hence it may be the precursor to the householder coming to investigate the noise...

Mungo

[Suz]

Ugly ugly.

[Allen]

OK, OK! You have a point.

Thanks to everyone for the replies. I'm still looking for a cheap and effective and long-lasting solution. I don't really want to alter the wiring from the ceiling rose to the light switch like someone suggested - although it was a much appreciated suggestion.

I have a vague idea that someone once told me that if you use those PIR wall-ligh switches (designed exactly for this purpose i.e., not designed for security lights) they will last longer if you use low energy bulbs - even though the instructions say DON'T use low energy bulbs..

Can anyone verify that?

Allen

[Allen]

Thanks for this suggestion. I did look into this idea once before, but I'm fairly sure that all the ones I looked at weren't suitable for some reason. I can't remember why though. Could you give more details like what you wired it to? Wiring from the wall swithch? Wiring from the ceiling rose?

Thanks

Allen

[Mungo Henning]

Hi Allen,

Now I'm presuming it ain't multi-way switching, so at the ceiling rose there is a "drop" which sends permanent-live down to the switch and switched live back up from the switch. So you take a three-core-plus-earth cable from the ceiling rose which has the blue core as Neutral (I try and wrap a bit of black tape over the blue cable so that the next person knows I am using this as a neutral), the red core as permanent-live and the yellow core will be switched live which will go to the live side of your lightbulb.

Live, Neutral, Switched Live and Earth: three cores plus earth to the PIR.

Mungo.

P.S. If you'd like to visually discriminate between the switch working the incandescent lamp and the PIR causing the light to be illuminated you may care to use Google to search in this newsgroup for an idea I broached about using a "power diode". Great idea (if I may say so): works a treat in my house! :-)

[Allen]

Mungo, Thanks for those directions. It does sound a bit complicated and I'm not at all sure whether the existing lights are one-way or two-way switched. But perhaps I'll try to figure it out. I'm not an electrician, though I have done a fair bit of DIY wiring..

Allen

[Mungo Henning]

One-way switched is what I described - the light only has one existing switch to work it. Two-way (or three, or four) means that the light can be switched on or off by two (or more) switches - slightly more complicated wiring for it.

It should be fine to do. Start it at daybreak to give yourself a few hours of natural light... :-)

Mungo