Help wanted with em fittings please

chocca · Sep 12, 2012

Hi all, I'm working on some maintained
em lights at the moment and theyrr doing my head on grr! They work fine as ems on power failure. but won't strike when power is restored. then, randomly one or two will come back on over 24hourd or so . they're tridonic combi ballasts on single 49w tubes. I've swapped some for new ballasts but the problem persists. Any ideas?

tazz · Sep 13, 2012

sparkatus12 said:
Had a problem once where new fittings worked fine and switched correctly. However in emergency mode lamps only stayed on for a few seconds. Turned out when engineer came out the batteries were fitted with reverse polarity in the factory. (Killing the batteries.)

I give up............!!!!!!!!!!!!!

Guest111 · Sep 13, 2012

As Tazz has said it has to be on the control side,if the fittings are new then that rules out a problem with fittings as its unlikely they are all faulty,try testing for a voltage with something that puts a load on the circuit rather than a digital meter as the current drawn by a meter is very small and sometimes they will read say 240 v but when you put a load on the voltage disappears and it can be someting as simple as a loose connection but relying on the meter saying you have the correct voltage there you spend ages chasing your tail.

Rampage · Sep 13, 2012

Would it be easier to turn them all on then check the voltage?

Merl · Sep 13, 2012

Had a similar problem months ago with tridonic combo ballasts. Lamps would strike and stay lit on battery back-up, restore the mains and lamps would flash twice and stay off. Turned out to be faulty lamps.

Try new lamps as nick suggested in post #10 if you haven't already.

Keep us posted if you get to the bottom of it.

chocca · Sep 14, 2012

Well gentlemen, the problem has gone away for now but without me finding the solution...

In response to the voltage questions, the fittings that are faulting are on a circuit of 10 lights and only 2 or 3 are faulting - voltage is ok.

The batteries in some of the fittings are brand new - the original fault developed when I was changing the packs after they failed the 3 hour discharge test and I'd had the circuits turned off. As described above by Merl, they flashed twice on restart then wouldn't come back on.

When I got there yesterday most of them had come back to life.

Tried changing the lamps in the remainder to no avail and finally changed the ballasts again and the tinkers worked.

I've returned the ballasts to the supplier and asked to be informed if anythings found...