Time switches with Low Energy Lighting

[Bankrupt]

I bought some time switches recently and they say "not suitable for use with Low Energy Lighting"

Why are time switches unsuitable for Low Energy Lighting and why do many PIR lanterns say not to use energy saver bulbs ? . ( I know that Energy Saver bulbs won't last long if turned on and off frequently, apart from that I can't understand what the problem is - Why should it matter what turns a circuit on and off ? ? )

I'm using one of the switches to turn my LED Christmas lighting on and off and it seems to work fine....

 

[Taylortwocities]

Its either because the switching contacts (or in some cases semiconductor) cannot handle the relatively high start-up currents of low-energy lamps,
or
maybe because Energy lamps don't work well in fast on/off environments (PIR eg) as they need a few mins to get up to full illumination.

 

[ericmark]

As Taylortwocities said the semi-conductor switching can't stand the high voltages generated on switching from discharge lamps.

 

[ccam108]

Some timer switches which are designed to replace existing standard light switches connect to the live only (no neutral) and so pass a small current through the lamp to power themselves. Not enough to illuminate the lamp, only a couple of mA. This is fine with standard filament lamps, as they are a resistor for all practical purposes but energy saving lamps do not take to kindly to this, some may flicker randomly and some might not work at all.

Colin C

 

[Steve]

Some timer switches which are designed to replace existing standard light switches connect to the live only (no neutral) and so pass a small current through the lamp to power themselves. Not enough to illuminate the lamp, only a couple of mA. This is fine with standard filament lamps, as they are a resistor for all practical purposes but energy saving lamps do not take to kindly to this, some may flicker randomly and some might not work at all.

Colin C

Yes, most will flicker lightly every few seconds. But its not a problem for the lamp. The timer may not like it, as the lamp is restricting the flow of electrons.

 

[ccam108]

Yes, most will flicker lightly every few seconds. But its not a problem for the lamp. The timer may not like it, as the lamp is restricting the flow of electrons.

Sorry, I meant the timer doesn't like it, as the energy saving lamp in non-linear.

Thanks for pointing that out.

Colin C

 

[bernardgreen]

Yes, most will flicker lightly every few seconds. But its not a problem for the lamp. The timer may not like it, as the lamp is restricting the flow of electrons.

Good quality lamps will not be affected by the flicker but some lower quality lamps ( components working on their limits ) may have a shorter life time due the flicker ( start up of the tube stresses some components beyond the recommended maximum ). Low price does not equate to low quality.

In a semi-conductor switched timer or PIR there will be protection components around the switch absorb transient voltage spikes but these allow a milli amp or two of current to flow when the switch is off. This small current will charge a compact flourescent lamp invetor's input until it can flash and discharged leading to a flicker every few seconds.

For security lighting the slow build up to full brilliance is a disadvantage.

 

[Bankrupt]

Thanks for all your replies.

Do you think my Christmas lights will be OK on an a timer ? - I have 450 LED lights being switched - 3 sets of 150 lights. Each LED light is 2.2 Volts and .12 Watt

 

[Steve]

Yes. Mechanical plugin timers have mechanical contacts anyway, so dont worry. They are all capable of switching 3kw.

 

[Bankrupt]

Thanks - It is a mechanical plug in timer. .