Problem with failing lighting ballasts
Problem with failing lighting ballasts
(OP)
Hello,
In our plant, we have 5 buildings with maybe 200 similar fluorescent fixtures, all with GE ballasts. In one building in particular we have a very high incidence of failure. 5 ballasts (out of 16) are being replaced this week.
This building is the sand blasting building. The equipment in the building are one 200 Hp compressor, lights, some fans, small heaters, etc. The compressor is the only significant load. No VFDs, welders or otherwise noisy loads. The lights are the only single phase loads on the 480V bus. There are two 277V circuits (different phases) dedicated to lights. The ballasts that failed are all on the same circuit. The building is on it's own 300 KVA transformer.
GE says the failures are due to the voltage swings caused by the compressor cycling on and off. They told me that the voltage could spike up to 360V when the compressor shut off. I have no idea where they came up with that. The transformer is fairly small, and I estimate that the voltage would drop 20% on starting. But I don't know that voltage sags would hurt the ballasts. I don't know how often the compressor cycles, but it is a compressor so it probably cycles quite a bit.
I had considered that the sand blasting building has a tremendous amount of very fine silica sand, All of the failed ballasts are in fixtures near the main blasting area. All the fixtures that failed are in the same area and on the same phase. GE said that the sand couldn't/wouldn't cause the failures.
I'm out of ideas, and I don't have time to turn this into a research project. Does anyone have any ideas what could be causing the ballast failures?
In our plant, we have 5 buildings with maybe 200 similar fluorescent fixtures, all with GE ballasts. In one building in particular we have a very high incidence of failure. 5 ballasts (out of 16) are being replaced this week.
This building is the sand blasting building. The equipment in the building are one 200 Hp compressor, lights, some fans, small heaters, etc. The compressor is the only significant load. No VFDs, welders or otherwise noisy loads. The lights are the only single phase loads on the 480V bus. There are two 277V circuits (different phases) dedicated to lights. The ballasts that failed are all on the same circuit. The building is on it's own 300 KVA transformer.
GE says the failures are due to the voltage swings caused by the compressor cycling on and off. They told me that the voltage could spike up to 360V when the compressor shut off. I have no idea where they came up with that. The transformer is fairly small, and I estimate that the voltage would drop 20% on starting. But I don't know that voltage sags would hurt the ballasts. I don't know how often the compressor cycles, but it is a compressor so it probably cycles quite a bit.
I had considered that the sand blasting building has a tremendous amount of very fine silica sand, All of the failed ballasts are in fixtures near the main blasting area. All the fixtures that failed are in the same area and on the same phase. GE said that the sand couldn't/wouldn't cause the failures.
I'm out of ideas, and I don't have time to turn this into a research project. Does anyone have any ideas what could be causing the ballast failures?





RE: Problem with failing lighting ballasts
RE: Problem with failing lighting ballasts
EE
RE: Problem with failing lighting ballasts
I wonder if it used to have such a feature, and it got repaired out.
Mike Halloran
Pembroke Pines, FL, USA
RE: Problem with failing lighting ballasts
RE: Problem with failing lighting ballasts
Please check if the compressor cycles on and off. My experience tells me compressors with that type of loading needs only to unload (vent off when air banks are full and load up when air bank pressures drop to a set level), not put off. That way you do away with erratic voltages.
RE: Problem with failing lighting ballasts
I might also look into having the electricians install caps on the ballasts. A 0.1uF capacitor with proper voltage rating might do the trick.
Thanks for your help.
RE: Problem with failing lighting ballasts
Also how are the ballasts mounted?
RE: Problem with failing lighting ballasts
RE: Problem with failing lighting ballasts
RE: Problem with failing lighting ballasts
RE: Problem with failing lighting ballasts
Another thing I don't know is whether all of these ballasts failed all at once, or over some time.