How to tell if a ballst can run t5's?

[sandiegan]

How do you tell whether a ballast can run T5's (or HO T5's for that matter)? Is it really just a matter of having enough wattage? For instance, I have an Advance ballast REL-4P32-SC On the ballast it shows info for running 4 lamps, but they're T8's. It's an instant start electronic ballast if that matters.. TIA guys

 

[Icefire]

You could try it but it look like to be T8 only

You might be able to drive T5 if you put the wattage lower and use all wires

 

[PaulErik]

If you want to use T5 lamps you should use a different ballast.

That ballast will light and operate other lamps but is only designed to operate T8 lamps safely. The problem operating T5 lamps with that ballast is it will continue to operate the lamps if one or both of the cathodes fail on one or more of the lamps. When one cathode fails the lamp will still able to light but will draw an excessive amount of current. T5 or any other small diameter lamps are not designed to handle this added current. The extra current makes the lamp operate at an extremely high temperature. This will cause the end cap to melt and the lamp will light until the glass bulb breaks/cracks. This is a huge hazard and manufacturers only recommend using T5 and other small diameter lamps on approved ballasts. Approved ballasts have safety features (End Of Life circuit and/or current limiter) so this cannot happen.

 

[ReefGirlSara]

I just saw this thread and was wondering what about the other way around? I have a ballast with 2x 54 watt T5's on it now, will it work for VHO's? Based on PaulErik's quote above, I don't see why not - but I don't know.

 

[PaulErik]

If the ballast you are using for your T5 HO lamps is a T5 HO spec (designed for T5 HO lamps) ballast then it will not properly operate T12 VHO lamps. The maximum wattage lamp a T5 HO 54-watt spec ballast can properly operate is approximately 54-watts each.