[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: T8 ballasts

Paul wrote:

I wonder if anyone can fill me in on the differences between T-8 and
T-12 Ballasts.
I have several 120W T-8 Ballasts that are rated to run 4 F32W T8 or
3-F40W T-8 bulbs (Basically 120 W peak load).
   Does anyone have the specs;  Amperage and Volts from a 120W T-12

I reply:

Your ballast is probably an instant start parallel electronic high freqency
ballast. All T8 ballasts put out the same current per lamp regardless of
lamp length. If I recall correctly it is 265 mA while ballasts for 4' T12
lamps use a much higher current. This ballast is intended to run 4' and 5'
T8 lamps. If it works at all with T12 lamps it would just be a complete
fluke. Just use T8 lamps and you will be fine. I find 4' T8 lamps to be much
cheaper anyway. It is quite possible that this ballast can also run 3 F32
lamps at a higher ballast factor than it would when running 4 lamps. If I
were going to experiment I think I would try that instead of using T12
lamps. It might burn out the lamps quickly but they are so cheap anyway. I
think that this can be quite valuable for getting the right amount of light
over an aquarium in a reasonably small space. What brand of ballast is it?
It sounds pretty interesting.  Maybe I can find out the ballast factors for
this ballast.

This ballast has probably been designed with both imperial and metric
standard ceiling grids in mind. A 3 lamp 5' fixture would certainly put out
as much or more light as a 4 lamp 4' fixture and the same ballast can be
used in both fixtures. I think we are going to see a lot of these sort of
multipurpose ballasts in the future. Two of these ballasts would probably
work very well with a 100 gallon 5' long tank. A very nice tank indeed.