On Fri, 29 May 2015 17:06:15 +0100, GB
wrote:

Flashing bathroom light - whilst switched off!

This is 2 yrs after a complete rebuild. Recently, the bathroom light has
started to flash whilst switched off. It flashes very briefly once or
twice a second. It's a fluorescent 2D fitting, two wires, no earth.

I suspect one of three reasons:
a) Problem with the switch that allows a small amount of current
through. Seems unlikely. The switch looks fine, and the light switches
on and off okay.
b) Water ingress into the fitting. But this looks fine. No sign of water
damage. And, in any case, it's switched off, so it should have no live
feed. (Yes, I know that live and neutral sometimes get muddled up, but
even so where's current going to without an earth?)
c) Water ingress into the wiring somewhere where I can't see it. This is
in a flat, so $deity knows what the person in the flat upstairs lets
overflow.

Any help would be appreciated.




it's actually a common well understood phenomenon, caused by the
capacitance in the order of a few hundred picofarads of the cable run
to the switch.

What is needed is a high value resistor across the lamp to quench the
voltage induced when the switch is off.

You may well find that changing the 2D lamp for a different brand will
cure it.


--

Graham.

%Profound_observation%