Ballast cases and fixtures must always be grounded. The ballast case may be grounded to the fixture or otherwise connected to ground. It would be hazardous to make contact with an ungrounded fixture or ballast when in operation. Neglecting to properly ground the ballast and fixture may result in the failure of certain lamps to start.
If improper grounding is suspected, check for poor contact due to excessive paint on the fixture, loose mounting of the ballast or surface rust, which may be impeding electrical contact.
For reliable starting, each lamp must be mounted within the following distances of a grounded metal fixture, or grounded metal strip running the entire length of the lamp.
- T12 Rapid Star: 1/2 ”
- T12 Slimline, 800ma or 1500ma Rapid Start: 1”
- T8 Rapid Start: 3/4 ”
- T8 Slimline: 1-1/4 ”