I have had about 8 ballasts go bad on my 3-year-old Anthony freezer doors. 2weeks ago I replaced one with a date of 11/07 on it, so it had obviously been replaced before. Today it is bad a 3rd time, and the 2 bulbs it serves have melted the plastic tubes on both of the top ends and have dark ends of the glass. What could cause this? We do have a lot of power surges and outages including 2 today, because our electrical infrastructure on the island is crumbling. But this particular ballast seems to be a problem. I replaced both bulbs and tubes along with the ballast 2 weeks ago and it worked flawlessly until today. Any ideas what the problem could be? Could it be related to the stockers leaving these doors open while they restock and the ballasts/bulbs are overheating?

Also, does anyone know a good supplier where I can buy ballasts and sleeves? The cheapest I have found is about 3 times what the customer expects to pay.

They are F72T12CW/HO bulbs with a 120 volt Anthony ballast, #60-14728-0001 FEP-120-272-T12HO.