Some years ago we retrofitted a minimum security jail using dual voltage electronic ballasts (120/277 volt). The first building required 128 ballasts and the fixtures were connected to 120 volt circuits. The installation was labor intensive due to access to each cell. Within two days after the first building was completed 28 fixtures were out ??? We went by our supplier and picked up replacement ballasts which happened to be straight 120 volt rated, and replaced the failed units. The failed ballasts were returned to the supplier. After a week more about twelve fixtures were out. At that point we needed to determine our problem because the costs of accessing many areas was getting too expensive. We did some testing on a damaged ballast. We found it would function on 277 volts but not on 120 volts. We came to the conclusion that our installation was subjected to some voltage surges which caused the ballast to shift to the higher voltage rating and then would not operate on 120 volts. All the 120 volt repacement ballasts functioned without any problem. We then replaced all the existing dual voltage ballasts with straight 120 volt electronic ballasts -- which solved the problem. We were told by the manufacturer's engineering department that the ballasts will not operate at the lower voltage once operated on the higher voltage??? We never use dual voltage ballasts !!
