Customer called and said that their lights were staying on. The photocell was installed 4-5 months ago so I installed a new one. After a day of use, the new one was doing the same thing. I tested the oginal one on the bench and it works flawlessly. The photocell controls 8 Fluorescent line voltage fixtures. It is mounted on the side of the unit that houses the transfomer/ballast for the first fixture in the run. They pull a little over 100 watts when on. Has anyone seen any issues with mounting a photocell near the transformer/ballast? I used the original photocell on a low voltage transformer on the property and it has worked fine.