Energy saving lamp flickering with NO supply..

[flyingsparks]

Changed some kitchen lights today, went to do my IR tests for the minor works form and got bad readings (approx 0.2M between L-E and N-E) Matey told me there was a flickeing lamp in another room (same circuit tho as the kitchen lights) went and had a look and with the switch off it just flickers every couple of seconds. Works fine with the switch on.

Rather strange I thought - any ideas what could be causing it?

PS it is a BS60898 MCB supplying the circuit.

Thanks.

 

[JohnD]

flickering on compact fluorescent likely to be induced current

happens most often on 2-way switching or if there is no earth in the cable

look up "flickering" and you'll find lots of them

"search" button above

 

[Adam_151]

Capactive coupling, John (Theres going to be no current flowing in your switch drop when the switch is off )

But yeah, this problem need not indicate a fault, but it is more likely to show up when there is no cpc 'shielding' the switch feed from the switch wire, so make sure cpc is connected to earth, with two way arrangements it can be quite difficult to make sure the two sides are always separated even when the cpc is connectedd... you may not be able to achieve it!

The other thing that can make it worse is switches in the neutral and not the phase, as the cpc then adds to the problem rather than reducing it!

Thats as well as poor IR, obviously

So check continuity of protective conductors, IR, and polarity and if that test out ok, tell the client that the flicking light is nothing to worry about! (if the ceiling is high, you could fit an extra long drop flex to counteract it )

I'm assumeing IR cleared up after removing CFL?

 

[Taylortwocities]

Some manufacturer's lamps are prone to this.
Easy solution is to try another (better) make or persuade them to swop back to regular tungsten lamp.

It is possible to solve this problem by hanging a capacitor across the lamp feed in the pendant (0.1µF 400V wkg) but this is not recommended - it will cause the next sparky real problems with his IR testing!