Passive IR for lights

[Paul]

Currently our hall lights has a switch at either end that switches them on or off. We want to use a motion sensor to switch them on automatically, is this possible and who sells the equipment necessary?

[Harry Bloomfield]

You can. You can buy a PIR head which will do this and can simply be wired across the switch circuit. The only only ones I have seen are intended for out door use, but I suppose they must sell one more suited to indoor use(?)

An electrical whole saler might be a good place to ask.

The out door ones are the same as the ones which are fitted to the security lights, which you can buy for £7-ish these days, but the separate PIR costs much more (>£20).

If in series with a CFL type lamp, the CFL does not pass enough current to allow the PIR to operate, but there is a fix for this.

[James Hart]

I've seen these quite often in public places like hotel corridors and toilets, they are quite small compared to their outdoor equivalent and look like a good idea to me. The last hotel I was in had them in the corridors and triggered a timer for the lights, no point leaving the lights on all night if no one's there to use them. Where to get them from? I suppose they'd be more commercial than domestic use so some of the online dealers should have a choice of them.

[Andy Hall]

Some of the inexpensive German hotels have them, and I don't mean the ones where you pay by the hour.

have the switches as "DN WAOC"

.andy

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[Paul]

Thanks, bit pricey though. Will these work when the two switches work the same circuit? If we get two PIR switches would it switch on only to immediately be switched off by the other one?

[Andy Hall]

Mmm. You might want to Google for "occupancy switch" and see what comes up..

I don't know for this one. The data sheet is scant.

.andy

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[Harry Bloomfield]

Paul wrote on Sunday (08/02/2004) :

There are ways you could wire it up....

1. Would mean it would energise the light ignoring completely the setting of the two way switches. The light could thus be turned on by the PIR or the wsitches as normal.
2. You could wire it up so that it would ONLY light up when the two way switches were set for it to come on (not advisable).
3. You could do away with the two way switches and rely entirely upon the PIR(s).

Either of the above could be done with two PIR's, one looking from one end of a corridor and a second from the other end.

[Paul]

Would this be suitable for what I need?

[Harry Bloomfield]

Qualification to the above..... Some of the possibilities above, would be made easier if the PIR was of the type which required their own nuetral, versus the type which is intended to work without a nuetral.

[Harry Bloomfield]

Damn, I just keep getting it wrong... sorry, folks.

The holes. Replace the plugs before it was then possible for the jack sinking and the weight coming onto each other lighting circuit pin in a secure box.

We tend not to bother locking up, avoiding the infants.

So I can only assume many people are being put off from posting by this rubbish.

I know when I don't manage this, by the type which is broadband. Two names for the concentrated content. Any items which are filtered, I netkkkop.

[Andy Hall]

However, I would check with the supplier.

However, if these are genuinely two way then putting one at each end and wired conventionally is probably not what you want. It would result in the light going on when one sensor picks you up and off again when the other does.

I think that probably what you want is two single pole switches wired in parallel such that if either or both trigger the light comes on. THis would need a bit of rewiring to achieve, but that may be possible without running new cables depending on the method used for the existing setup.

One thing to check would be whether it is acceptable from the switch's point of view to have two in parallel. It might not be depending on the design

I found another switch -

part XX52G It doesn't say whether paralleling is OK for these.

.andy

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[Lurch]

I've used a lot of these in the past. You'd probably be best off going into an electrical wholesalers and enquiring about availability and pricing etc... Go to the lightspot range.

can be wired in parallel if you want one at each end of the hallway. I would suggest leaving the existing switching in place, or at least one of them, to be able to turn the lights off completely for any reason. To do this just wire the circuit as normal but instead of putting the switch wire in the light fitting into the live terminal put it into the feed terminal in the ex-or, then run the switch wire from the ex-or into the live terminal of the light fitting. As a note for future reference I haven't come across a PIR yet that doesn't require a neutral and that can't be wired in parallel with a switch or other PIR. ..

SJW A.C.S. Ltd.

[nightjar]

I bought mine from Screwfix. It is called Infrascan and I use it to operate my bathroom lights. It will work as a fully automatic system or with manual over-ride switches.

Colin Bignell

[Dave Stanton]

Argos used to sell them.

Dave

[The Most Rev. Peter Parsnip]

The Lord alerted my mind to the presence of this EVIL article by Harry Bloomfield, and I thusly replied:

Agreed.

[Phil Kyle]

You know nothing about PIR, so shutit.

[Phil Kyle]

What does nuetral mean?

[Phil Kyle]

Wow, a Frank admission.

[Justin]

try this, I've just ordered one