PIR room sensors and CFL lamps....

[Engineer54]

Never really thought about it before, but today the contractor replaced a CFL lamp in my office that had been flickering for a couple of days. I just happened to pick-up the lamps box and reading the usual fluff the manufacturers print on these boxes read this statement. ....Not suitable for electronic dimmers or other electronic remote switching!!

Now these fittings that have been installed in our site offices, are in some rooms controlled by room PIR's such as the loo's, drawings storage rooms, other storage rooms, etc. Had a look at the light fitting manufactures instruction leaflet in a one of the spares that we have and in that it states, ....Suitable for PIR switching (among others methods)!! The PIR sensor info sheet, also gives max Wattage associated with different lamp types including fluorescent loads!!...

Now these fittings are made for CFL lamps, and the CFL lamps that the contractor are supplying are Phillips. So what's the SP, are CFL suitable for PIR switching or not?? ...lol!!

I'm just curious more than anything else... lol!!

 

[grumpyjohn01]

We installed some PIR bulkeads on a housing project some years ago and put ES low energy (CFL) GLS replacement lamps in them....and 1 by 1 they all stopped working..! generally PIR stuck closed ie lamp on all the time.

 

[Engineer54]

We installed some PIR bulkeads on a housing project some years ago and put ES low energy (CFL) GLS replacement lamps in them....and 1 by 1 they all stopped working..! generally PIR stuck closed ie lamp on all the time.

Now i would have thought the opposite would have been the case!! lol!!

 

[grumpyjohn01]

They have a fairly high capacitance don't they?

 

[Knobhead]

Inductive

 

[D Skelton]

There is no reason why you can't switch a CFL with a PIR but CFLs aren't designed for constant switching, hence why they fail quickly when on PIRs. CFLs work best/last longest when energised for long periods.

 

[electric will]

We/I use a lot of led lighting in display cabinets, main reason is not as much heat generated as the halogens, then the fact they last a hell of a lot longer, finally they use less power.
Had major issues with breakers tripping ( upto c) when all cabinets switched on at once, had contacts fail in 13a switched spurs, then even 20a double pole switches.
The running load of our displays was 3-4 amp max.
the start up/inrush of these things must be massive.
i now fit time delayed contractors to stagger the LEDs starting up.

 

[HandySparks]

....Not suitable for electronic dimmers or other electronic remote switching!

What it generally means by this is devices that use a semiconductor triac or similar for the actual switching, as opposed to an ordinary switch or relay. So a PIR with relay output is just fine, provided that it's suitably rated for the inductive load (apart from the issue of frequent switching reducing the life of the CFL).

 

[Engineer54]

What it generally means by this is devices that use a semiconductor triac or similar for the actual switching, as opposed to an ordinary switch or relay. So a PIR with relay output is just fine, provided that it's suitably rated for the inductive load (apart from the issue of frequent switching reducing the life of the CFL).

I would think that is is true of any lamp type!!

 

[HandySparks]

I would think that is is true of any lamp type!!

To an extent, yes, but frequent switching is particularly bad for the life of most fluorescents and CFLs. On the other hand, LEDs shouldn't be much affected by switching.

 

[CTID]

Manufacturers will state not to be used with PIRs as they can reduce the life of the lamp, this due to the time selections on PIRs which often mean regular switching. It is the start up load on the CFL that impacts its life span. They are only not recommended as manufacturers will have stated on the box an expected lifetime, e.g. 10,000 hours and obviously this won't be achieved with PIRs. If you are using PIRs, make sure that areas that are frequently used have the PIR timer turned up to maximum, normally around about 45 minutes. This will reduce excessive switching of the lamp and therefore extend the lifetime. I have been to some offices where lamps where regularly failing, we found the PIRs set to only 30 seconds or so and as such were constantly switching the lamp, obviously this meant lamps were only lasting a month or two.

 

[Deleted member 9648]

We've had problems with megaman 60w clusterlamps on P/c's....on/off once a night. Lasting less than half manufacturers quoted life expectancy and a fraction of the quoted switching cycles. I'm certain CFL and LED lamp manufacturers pluck their life expectancy figures out of the air.

 

[i=p/u]

Just set pir sensor long enought to let it heat up. I.e I set them for 20 mins when changing , need anymore advice pm me e54