In article M6GHi.3333$Ap2.2805@trndny05, "James Sweet" wrote:

"G" wrote in message
...
I have a system that worked. Had a lamp and a ballast. It quit
working. I replaced lamp and ballast, check everything except the voltage
between the ends of the tube. The filiments light. My question, its a two
lamp
ballast that has two unused wires. Having only one lamp connected, could
this
cause a reduced starting voltage across the lamp. I am suspecting
some weak link and not a hard core problem.

greg

Are you sure the ballast is wired right? Most North American twin lamp
autotransformer ballasts wire the lamps in series, the output of the
secondary is on the red and blue wires, the yellow wires are only a small
winding to provide cathode heat to the middle cathodes.

Yellows on one side, one lamp to reds and another if present to blues on the
other sides. 120 vac. I checked voltages except the actual drive, supposed
to be about 380 vac unloaded. I will measure that next. I had to defeat
contacts to get access. Its all in a big hood. It worked, now it still does ot
even with new parts. I don't imagine there is a problem with the socket since
the filiments light. Its also a UV lamp.

I wired up a strobe once. It would not work in the dark. As soon as you gave
it enough light it would fire.

greg
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