My kitchen lightswitch has been replaced by a PIR detector (domestic reasons).
The light itself is a 6 unit bar, using low voltage 35 w GU 10 bulbs.
Having worked without problems for fifteen tears or more, the lights have suddenly started flashing on and off when the unit switches off. They don't all flash in unison, but no discoverable sequence either, seems to be random.
I have replaced the unit, but the fault is still there.
Any ideas? The bulbs can't flash without a voltage, which must come from the switch, but two different units, one well used and one brand new, are hardly likely to have the same fault.
Did you check that the PIR switch was compatable with the lighting unit/buklbs you have?
I fitted a pair of PIR's to operate the upstairs and down stairs light for an elderly person a few years ago. I found that they were not compatable with the old style energy saving light bulbs, they worked for a while and then stat to switch on and off so fitted normal bulbs. I've never tried them with the new energy saving bulb supplied today.
Very odd fault, I have GU 10 bulbs in my bathroom and they are 240V low energy but not low voltage. As you say they must have power to light up and flash. I would be thinking you may have developed a wiring fault i.e. live into the switch and live out from it shorting before the switch.
Thanks for the responses. My apologies for the lack of clarity, I will try to answer.
The bulbs are, as you say, mains powered, don't know why I was convinced it was a low voltage unit.
As I said, the PIR unit has been in fault free use for fifteen years or more, so compatibility is unlikely to be a problem. This would also apply to the positioning of the unit.
I should clarify that the flashing is more a milliseconds flash like a photofash regather than the regular flash of a car indicator. Switching on is perfectly normal. as soon as there is movement in the room.
The flashing does on for at least two hour after switch off.
Both units are Ecoswitch LC-750S, two wire system, earthed through the backing plate and fixing screws. There is no manual override. The design seems fairly stable as the new one looks identical to the fifteen year old one.
The other problem it might be is mains born interference making the unit switch intermittently. Try listening on a medium wave radio, tune it to a clear frequency an listen for any interference that coincides with the lamps flashing. It could be a lose connection somewhere in the house creating the interference, the radio will soon pick that up.
It's not something silly like a radio amateur moved into your area, I know I create havoc with our outside PIR's.