I have two 175 watt HPS fixtures that have been out of service for a few years that I reinstalled today. Upon installation and powering up, both these units light up for a while then go off. They immediately relight for a while and go off again continuosley. The one unit will light for only about a minute or two. The other one however will light for a longer period of time, maybe 10 minutes then go off. These are both Hubbel fixtures. Anyone got an answer for this? Is the ballast causing this or what? I can't see both of them doing the same thing. They were working when they were taken out of service the first time. Thanks in advance for any thoughts.
