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Shroomster
07-03-2009, 12:51 AM
OK so our house has 2 single fixture fluorescent lamps in series (I believe they're in series). They have been giving us problems with almost no start-up without flicking the switch constantly. The previously installed ballasts were lag-type. I replaced the ballasts once with the same 'lag-type', and they worked pretty decently the past year or so, until now.

I decided to do some research and found the fixtures call for the use of Trigger-start ballasts.

Are trigger start and lag-type the same?

I can't seem to find anything that says they are or aren't.
CTScott
07-03-2009, 01:11 AM
They are one in the same. If you want to improve their starting, life span and improve their electrical efficiency, switch the ballasts to electronic ones. Just make sure that you purchase ones that are rated for the same bulb type (F40T12 for example), so you don't have to change the bulb sockets.

By the way, the fixtures are connected in parallel. If they were in series, each would only receive half of the circuit voltage (i.e. 60VAC instead of 120VAC).
Shroomster
07-03-2009, 01:58 AM
Just make sure that you purchase ones that are rated for the same bulb type (F40T12 for example), so you don't have to change the bulb sockets.


that was the one thing I was concerned about too as I purchased Energy saving bulbs and I read that some are not back-wards compatible with some ballasts/fixtures. but if that were the case the ones I have installed wouldn't light at all. that and the prongs are spaced differently as well.
CTScott
07-03-2009, 04:28 PM
that was the one thing I was concerned about too as I purchased Energy saving bulbs and I read that some are not back-wards compatible with some ballasts/fixtures. but if that were the case the ones I have installed wouldn't light at all. that and the prongs are spaced differently as well.

Correct. The ballast and bulbs must have the same rating. You can replace the bulb sockets (depending on the type of fixture). At most home improvement centers they sell the sockets right next to the ballasts. In a worst case, just upgrade the ballast to an electronic one rated for the same bulbs as the original fixture. You will still see an increase in efficiency, but not as significant as going from T12 to T8 bulbs, where a 4 footer goes from 40 to 32 watts with the same light output.