Energy saving bulbs & PIR sensors

[Jez]

Does anyone know why you are not advised to use energy saving bulbs on PIR sensor switched circuits?

I've got a few outside lights that have PIRs fitted and would like to fit them with energy saving bulbs. When filament bulbs get banned, I might not have much choice but to fit them anyway, so it would be good to know what problems are to be expected.

[Paulajayne]

Two things come immediatly to mind.

1. Start up time.
2. Size.

Paula

[Jez]

For those that are interested, I've just been informed by a person with an electrical bias that the reason that energy saving bulbs are not suitable is that they are an inductive load.

[Lowrider]

Apart from the fact that they're inductive, switching on and off is bad for an energy saving bulb. If you look at the light they produce when just started, it is slightly less than when it has been on for several minutes!

Size doesn't matter anymore since most are the same size or even a bit smaller than the equivalent in normal bulbs.

Why switch them on and off? I have mine on a lightsensor and timer.They go on after 1700 if it's dark enough and switch off at midnight, the next morning if it's still dark enough they will switch on again and go off at 9 or earlier if it's light!

When i'm not home I use the random function to occasionnaly switch them on during the night!

[Jez]

Why switch them on and off?

The only reason that they would be switched on and off was if there was a trespasser in my garden, or if either me or a member of my family went outside at night. I don't really want my garden lights on all night. Apart from the waste of energy, there is a light pollution issue.

Anyway, I've managed to find some separate PIR sensor kits from screwfix.com that are capable of switching an inductive load. They also have an overide function and the ability to only become activated during darkness. Just what I'm after.

[old gas bottle]

i put a couple outside at the back for the same reason as yourself ,but fitted energy savers without thinking,not had any probs yet, surley if they are timed to stop on for 5 mins or so it cant be harmfull to the unit, have dawn to dusk units on the drive fitted the same,been in years ,only changed the bulbs once,

[Jez]

I believe that some will work for a while, while others may not work at all. It probably depends on how expensive the units are. The cheap bulkhead units that I have with the PIR sensor incorporated specifically state that energy saving bulbs should not be used. The electrical chap that I spoke to mumbled something about TRIACs, but I thought they were some kind of Chinese organised crime group.

[momo]

Quality and suitability ?
I have doubts about the environmental friendliness of economy bulbs they contain a lot more than the steel, sand, aluminium and wolframium of conventional bulbs... they are fluorescents (phosphorous, mercury...) and have electronics (plastics, aluminium, germanium, ytrium etc - easier to mix than seperate) ...
The quality of most for length of life is doubtful - I had a policy in a hotel maintenance post of writing month and year when replacing bulbs to check as to which make lasted ... and they usually don't meet the hours of life they claim even as an average (the number of on hours could be worked out from the clock settings on the corridors and gardens) ...
Furthermore manufacturers of any worth specify the "number" of on/off cycles they are designed for... It becomes absurd therefore to use them in toilets where somebody goes in every three minutes (100000 cycles per year at 3 minutes) and the light is lit by a PIR on movement.
Heat accumulation is also a killer of these light sources in closed fittings, LEDs do not fare much better since they are also heat sensitive - but intensity and quality varies greatly.
(I put the colour in to prove I'm not a Luddite !)

[The MG Pony]

I have had the fluorescents last 7 years. Thats right From several houses it came with me and I never did see it die as some one stole it! The 15-Watt ones go forever, the 20-Watt ones don't last as long it seems, for the ones I use inside I care fully drill vent holes to help cool the internals, and the out side one I just leave running 24/7 as I use next to no lighting inside.

The 20 Watt round ones do last a long time, the type where you can replace the bulb. The units can be recycles too, infact BC here heavily pushes for that.

[momo]

MG Pony: I take note of your comment I agree with getting a good life from the short fluorescents with a separate ballast, its the ones with the electronic ballasts built in that don't convince me -and it was these that were the reason I adopted the dating policy - I assume Canada is on 110v 60Hz, that could help on the heat (resistance) and inductive efficiency side.

[The MG Pony]

Ya we are Average line voltage goes from 115 to 120, and the 60Hz never wanders.

[roumen68]

Hi!
I have problems with PIR sensors and energy saving bulbs. The problem is that when the sensor's relay output is off (no movement) the bulbs are flashing with frequency lets say 3-4 Hz. The light ammount during that flashing is low, but enough to irritate a person and to have a disco club feeling. Both the live and the neutral wires for the bulbs are conected to the sensors. Perhaps the neutral wire for the bulb shouldn't be connected to the sensor, but directly to the bulb? Note, that the problem exists only with energy saving bulbs. With standard bulbs there is no flashing. Anyone has an idea where is the problem? Thanks!

[Yuri B.]

Hello.

Could you put a picture of the contact box of the pir?

So, "off"on that pir is really "off" only for low resistive loads (incandescent bulbs) as you noticed. In this thread have been mentioned "inductive"ness of the fluorescent bulbs, and "triac." The semiconductive output on your device is passing some current making the bulb, which has very high impedance, to glimmer as you describe.

[roumen68]

Hello Yuri!

I think the output of the sensor is an electomechanical relay, not a triac. As it sounds "click" every time when it switches on and off. So, in this case the nature of the load shouldn't matter, am I right?

About the picture - I can shoot one tomorrow.

[Yuri B.]

I should disagree with you about load nature unimportance here.
The mechanical relay in your PIR is a "miniature" one, with very short gap between its contacts. There evidently remains a sort of an arc inbetweeen them - very very low amperage one (as the bulb's impedance is high and the load is inductive) unable to fully ignite the bulb, but which produce the effect you described.
Best regards.

[position1]

I have come accross a few of these sensor lights as described.

When an energy saver is inserted they will cause it to flicker.

It it deffinately due to a small leakage current. The manufacturers even spec this as been in the order of 1 to a few uA.

This would definately suggest something solidstate, like an scr doing the switching.

But I do have to agree with roumen68, that I hear a distinct click that sounds like a mechanical relay.

[position1]

I should disagree with you about load nature unimportance here.
The mechanical relay in your PIR is a "miniature" one, with very short gap between its contacts. There evidently remains a sort of an arc inbetweeen them - very very low amperage one (as the bulb's impedance is high and the load is inductive) unable to fully ignite the bulb, but which produce the effect you described.
Best regards.

Are you able to elaberate on these minature mechanical relays with leakage current.

Maybe a manufacurer part number of a relay that acts like this. I would just like read up on such a part, so I wont be as confused if I ever see one in the field.

[Yuri B.]

Are you able to elaberate on these minature mechanical relays with leakage current.

Maybe a manufacurer part number of a relay that acts like this. I would just like read up on such a part, so I wont be as confused if I ever see one in the field.

It has nothing to do with the relays brands - it may be a feature of any small el-mechanical relay when it is used with a load whose impedance difference between swithched-on and the switched-off state is very great. Look up into the specs of your pir - what type of bulbs it is supposed to be used with (I may be wrong, still my bet is it is solely the incandescents).

[roumen68]

These days I'll try something to solve the problem. I'll buy a standard 2 changeover contacts E/M industrial relay (8 pins) with a socket and in this way I'll separate the bulb's circuit from the sensor's circuit. I hope that the leakage from the sensor's relay will be too small to activate the coil of the second relay. And in this way I'll stop the leakage and the blinking. Or I just hope so.

[Yuri B.]

sensor's relay will be too small to activate the coil of the second relay. And in this way I'll stop the leakage and the blinking.

It will be. But you'll not stop the leakage - the leakage will just turn out to be too small to activate the coil (as you said it yourself), which has much lower impedance than the bulb had.

[roumen68]

Well, I would say that the bulb lights by blinking totally 0,2 seconds in each 1 second when the sensor is off. The bulb is 20 W, so it means that during the sensor's off status the bulb consumes 4-5 W constantly? If this is so, I start to doubt if it is a better idea to use standard bulbs instead the energy saving bulbs. In off possition there will be no leackage, right?

[Yuri B.]

My view is, use either an incandescent or a mini fluorescent bulb fed through the el-mech relay switched to the pir s output. It should be ok.

[Frikkie]

I have never seen 'leakage' across open relay contacts when it is use within its correct voltage specifications.
Leakage would suggest a solid state switch of some sort ie triac, diac, SCR, IGBT etc.
I have seen this problem with an motorised garage door opener which had a light built in to it that automatically came on when the door closed. This light was on a timer for 2 minutes and it also made compact fluorescent lamps flash because it was a solid state switch inside so you had to use a filament lamp.

Some 2 wire electronic timing devices (only live-in and switched live out) also use the neutral on the other side of the lamp filament as a reference and a very small current may flow. This current may charge capacitors inside the electronic ballast if a CFL is used. When these capacitors discharge they could cause he lamp to flash.

[Yuri B.]

A year or two ago I encountered such thing.

On a water cassette the condensate pump stopped to work. The pump turned to be ok, the float ok, but the pump was not receiving 220V from the triac on PCB.

The cost of a new PCB (very simple one, even no processor there – all relays and 2 or 3 transistors for the pump) being some 150 or 200 E – too expensive for the customer - and me not wishing to repair it, I rewired so that the pump received 220V through NO contact of an independent time relay (to ensure pump’s stable switching), but the relay’s “coil” – however it is electronic - got 220V through the hermetic NO contact of the cassette\s float. The pump now became “independent” from the PCB.

Checked all – started filling the tray with water: water level began to raise, the float went up, after a minute passed by on the timer, the pump started. Water level dropped, relay stopped, pump stopped. I went away.

Few days later the call: “noise from the cassette”

Came up – the tray empty, float in the low position, the timer energized, the pump runs “dry” (indeed, more noisy than when was with water). Measured volts (on the relay’s “coil”) - 220. Took off the lead - 0V. Again checked all – all ran ok.

After this second or the third visit it struck me that the timer continued to draw some current through the hercon after the latter “switched off” BECAUSE: the gap in the hercon is very short, voltage applied rather high (it should not happen with a lower voltage), timer’s impedance very high. I introduced a small el-mech relay in the chain of the hercon and it has worked since then.

[position1]

I have never seen 'leakage' across open relay contacts when it is use within its correct voltage specifications.
Leakage would suggest a solid state switch of some sort ie triac, diac, SCR, IGBT etc.

I totally agree.

Has to be solid state.

This mini-electromechanical relays with leakage stuff sounds odd.

Correct me if I am wrong, but a relay has either physical mechanical contacts (be it miniture or not) and doesn't leak, or is a solid state device and does leak.

[roumen68]

I totally agree.

Has to be solid state.

This mini-electromechanical relays with leakage stuff sounds odd.

Correct me if I am wrong, but a relay has either physical mechanical contacts (be it miniture or not) and doesn't leak, or is a solid state device and does leak.

OK, but how to explain then the clicking sound from the sensor. It sounds just like an E/M relay clicking.

[Voyager]

OK, but how to explain then the clicking sound from the sensor. It sounds just like an E/M relay clicking.

If you take one apart you will probably find both.
A solid state sensor (low load/voltage) used to switch a mechanical relay (high load/voltage) to power the light. Most car electrical systems work the same way.

The problem I have with these 'energy' savers is that it takes years to recover the initial investment. In my house, on top of the price of the bulbs, there is a huge cost involved in replacing the light fittings themselves.
Other than the 2 table lamps these bulbs actually fit, we have a triple spotlight with mini-bayonet, a triple spotlight with Small ES, a ceiling light with standard ES, 2 triple spotlights with end pins and 2 ceiling lights with mini-bayonet candle bulbs. Oh, and 2 PIRs.

Saving the planet could leave me bankrupt !

[Yuri B.]

By Voyager

Saving the planet could leave me bankrupt !

but will enrich the manufacturers of the bulbs and the fittings.

Just now have tried disconnecting very very slowly an improvised contact in the chain of such bulb which was lighting - no "leakage" get generated just a rather strong arc, corresponding to the few watts of the bulb's power, with the bulb absolutely dark. (and such arc should have burned in few minutes a relay on the pir)

What you Roumen68 have described is strange, I correlated it with what I have seen - the electronic timer was drawing current through the hermetic contact which was actually closed. However, what is the power of an el timer ? Probably less a watt - as compared to the 10 - 20 of a usual bulb.
It is high time to "rip the PIR" and find out what is going on.

[cadillackid]

ive been driving my outdoor CFL's off of a Triac based dimmer set on 100% setting for several years now... same bulbs.. same dimmer.. same PIR sensor... no issues, and they turn on at dusk, off at dawn....
-Christopher

[Frikkie]

A triac (or usually diac) dimmer module is configured to give a pulse width modulated output with a reduced RMS. It does this by switching very many times per second and this allows the lamp to run dimmer. This is not the same to using a triac/diac as a normal on/off switch.

The short solution here is to use known compatible combinations of components where possible to avoid anomalies such as flickering lamps etc.

[roumen68]

For 3 weeks of flickering, 2 of the new Philips energy saving lamps with 8 (eight) years of warranty burned out. I replaced them with also a new type of Philips 30% energy saving incadescent bulbs, dimmable. No flickering anymore!

[Sheeque09]

I would definitely recommend to use energy saving light bulbs. They save around 80 energy. Its a huge number and its good for environment as well as for your wallet.20W energy saving bulb will give you as much light as 100W bulb. It takes them a bit longer to properly light up but it does not bother me. They last longer usually 8 times longer and your electric bill drops down.

[et0]

I've installed dozens of PIR lamps and always put a CFL (low energy) bulb in them. Never had any problems - the bulbs have lasted, no flickering as mentioned above..

Don't worry about it.

[momo]

Came back to this thread monthe later... and about the flickering: relays on PIRs may have a capacitor in parallel with the contacts to reduce RF noise leaking some current. Also I have seen cases of CFLs flashing every so often near powerful radio (mobile phone) stations. In this case these lights were switched conventionally on the live line so the inner electronics were acting as an antenna!!! (Some did not last long!)