Ballast replacement

Customer has a produce case at his store with an 30 watt 4 ft. T8, and 32 watt 3 ft. T8 run off the same ballast. Old ballast went bad, was a Sylvania 2x32 Quicktronic electronic ballast. Replaced with standard 2x32 electronic ballast and only one bulb lights up at a time. Either bulb works, but not both at the same time.
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
F30T8 (36" T8) and F32T8 (48" T8) are not the same class and they're never intended to operate on the same ballast.

It's an improper use. While ballast may support 25W 3' as well as 32W 4', the use of two types on the same ballast simultaneously is generally not supported. To do something like this, you'll need to use a "sign ballast". Or use two single lamp ballasts.
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
LarryFine, the combination wattage is for dual lamp circline with inner and outer lamps.

The overwhelming majority of T8 systems are parallel wired and in theory, each lamp output is independent, but in reality they're not. If you have a 3 lamp T8 ballast and remove one lamp, the other two will get brighter. If you do something quirky like Two F32T8 32W full wattage and one F32T8/25W 4', you will often run into failed ignition of the energy saver lamp.
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Generally been replacing all T8/T12 with ballast bypass LED, OP situation it would seem a better option to consider the LED replacement.
 
Thanks for the info guys. It was working with the old electronic ballast, and it's basically a one to onw replacement. I would love to do the LED replacement, but that wiuld be a significant difference in appearance from the surrounding produce cases, and he does not want to shell out that kind of money. I think I figured out the problem anyway, looks like one of the tombstones was faulty.
 
Thanks for the info guys. It was working with the old electronic ballast, and it's basically a one to onw replacement. I would love to do the LED replacement, but that wiuld be a significant difference in appearance from the surrounding produce cases, and he does not want to shell out that kind of money. I think I figured out the problem anyway, looks like one of the tombstones was faulty.
Hmmm, not sure I agree with any of those points. Why would the appearance be different? Why would it cost more? Led tubes are like $3.50-$7.00 a piece 🤔
 

Flicker Index

Senior Member
Location
Pac NW
Occupation
Lights
Hmmm, not sure I agree with any of those points. Why would the appearance be different? Why would it cost more? Led tubes are like $3.50-$7.00 a piece 🤔
Aesthetic match is very difficult. Even the same model lamps from different lot can have noticeably different tint side-by-side.
Kind of like why body shops "blend in" instead of only painting the damaged panel. They might get away with doing this for a plain white delivery vans, but not for everything else.

If you replace just two lamps with LED while rest of the display cases have regular fluorescent lamps, that section will look different.
 
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