T5 Ballast Techie Question

[CageUK]

Would 36w T5 bulbs work with a ballast rated for 54w?

I bought a 54w twin ballast from ebay thinking it would work with 36w as well. When I wire them in, they flash once but remain off

I was hoping that the ballast would be for 54w maximum but would run lower value bulbs as well.

Appreciate the help of any techies out there.

Cheers

 

[andywg]

The ballast will overcharge the lights. They will give out more light but at the cost of tube life.

 

[CageUK]

Cheers Andy

Having looked at the labelling on the ballast, I'm guessing that it has a cut off feature to prevent that from happening and that is why the lights only come on briefly before going off again.
Anyone want to buy a brand new twin 54w 4ft ballast?

Cheers

 

[three-fingers]

Question!

Is this the case with T8's ballasts too? I had assumed the same as CageUK, except the tubes actually lit up when I did it with T8's. Would this cause any damage to the ballasts, or only effect tube life?

 

[andywg]

I am not aware of any damage to the ballast from overdriving (couldn't remember the term last night) as the ballast is operating as it should. It is only the bulb which is operating outside the intended parameters.

Overdriving should still be allowed by the ballast, it may be that the OP has a duff tube.

 

[three-fingers]

Awesome, cheers.

 

[SkiFletch]

Overdriving should still be allowed by the ballast, it may be that the OP has a duff tube.

Overdriving is definitely allowed by magnetic ballasts, but I would not be surprised if some electronic ballasts have overcurrent protection biult into them which would prevent them from firing/running normally.

To the OP, or anyone else interested in overdriving... Using a 54watt ballast (which is already overdriven on 4' T5 lamps) is a LOT of power to try and juice through small 3' T5 lamps. You'd REALLY decrease bulb live driving that much energy through that short of a bulb

 

[andywg]

I used to overdrive an NO 8W T5 (one of the old style ones) with a 24W electronic HO ballast for a fuge so at least some (though by no means does this equate to all) electronic ballasts allow overdriving. Got some great brightness out of that and it lasted at least a month (more than I was expecting)!