Outside light with PIR

[Mungo "Two Sheds" Toadfoot]

I changed the screw-thread 60w tungsten bulb for an 11w low energy job and now it won't turn itself off. Any ideas why?

Si

[The Medway Handyman]

Someone more knowledgeable than me will be along in a minute I'm sure, but I suspect PIR's & low energy bulbs don't mix?

[Mungo "Two Sheds" Toadfoot]

So it would appear. Thanks Dave.

Si

[Michael Atkinson]

Perhaps going OT, but I've long wondered what are the plans for dimming circuits and such when traditional incandescent bulbs are retired. Half our house uses such dimmers, and all the low energy bulbs I've seen state they're incompatible.

[Mungo "Two Sheds" Toadfoot]

He wasn't.

Me an' all. Most pissadointing.

Si

[Mungo "Two Sheds" Toadfoot]

Certainly did. Well written, that chap.

Si

[Mungo "Two Sheds" Toadfoot]

... WTF did I do with the old bulb??

See, you try to do your bit...

Si

[ARWadsworth]

You can get dimmable low enargy lamps, buy they are expensive

Adam

[The Medway Handyman]

Calvin.

That all makes sense, but how can you tell the properly designed ones from the crap ones? I mean without opening the box & taking the thing apart? Is it just price or are there any indications one might see in the spec? Or any specific makes?

[Mike Barnes]

Many years ago I replaced tungsten with CFLs in two cupboards. They're switched by mechanical door-operated switches rather than PIRs but the usage pattern would be similar. The CFLs definitely seem to last longer.

[David Hansen]

On Fri, 24 Oct 2008 21:23:15 +0100 someone who may be Michael Atkinson wrote this:-

Some are now dimmable. First there were the on/off switch dimmable ones which had about four levels, there are now on/off switch dimmable ones that are continuously variable.

has a few examples of ones which are dimmable via an existing dimmer switch.

There are many frequently repeated myths about energy saving lamps. Some of them were true with regard to the earliest such lamps, a quarter of a century ago, but engineering has developed somewhat since then so it pays to keep up to date. Examples of these myths include that they should not be switched on/off frequently and they take a long time to produce light. Both were true a quarter of a century ago, but have not been true for a decade or more.

[Andrew Gabriel]

There are areas where filament lamps do particularly badly. Cupboards with doors banging shut is a common one. Cooker hoods with fan motor vibration can be another.

[john]

What is the point in putting a low energy bulb in a PIR light when it takes a lifetime for the bulb to fire up Even then it will be useless. All to save what - a couple of pence.? or , and the world

[Owain]

Not to mention the wondrous series-parallel combinations of a couple of binobs and a Marvel switch.

Owain

[Mike Clarke]

The bigger problem is that before long a CFL will be the *only* thing you'll be able to buy to put in it.

[The Medway Handyman]

I thought you wern't going to mention that?

[Mike Barnes]

I take your point but "cupboards" didn't convey the right impression - my fault. They're actually store rooms with the lights mounted on the plasterboard ceiling, a good metre away from the door.

[Owain]

Youth of today don't have any idea of the fun that can be had with a binob.

Owain

[Huge]

Stock up. Lots of people are, so I've read.

[Calvin]

I'm not sure you can tell good quality from bad from the outside. Price is a negative indicator in that if it's cheap then for sure someones cut a cormer somewhere. The trouble is that something being expensive doesn't guarantee quality.

Anyway since writing that note on PIRs I've been thinking a bit more about it and I guess I was a bit harsh on the in-line ones. It's a kludge for sure and it definitely has its drawbacks, like not being able to use most CFLs, but maybe it's actually a clever bit of design to allow you to fit it in place of a normal switch without the hassle of running a neutral to the patress box. What they could maybe do a little better is explain some of that in the instructions, mine gave a range of wattages for different types of bulb and even though my CFL was within the range it flashed. Not much thought later I'd realised that of course there's no way for the PIR manufacturer to know the characteristics of the particular CFL. It would be much better if they'd said so, trouble is that once you start writing "maybe" on the spec sheet people stop buying the product.