When Should I use a Ground Wire?
Grounding is an Important Safety Concern.
Grounding the Metal on a Lighting Fixture Assures that If Any Electrical Component of a Light Fixture Should Fail the Potential for Electrocution Hazard is Minimized by Triggering the Circuit Fault Protector (House Circuit Breaker or Fuse).
Grounding Must Be a Continuous Connection through all Metal Parts.
Moving Connections are Not Considered a Good Ground (Such as Swivels, Hang Straights or Chain) and a Grounding Wire Should be Used to Join the Segregated Sections of the Fixture.
Crossbar Mounting Screws Should Not Be Considered a Ground. A Separate Grounding Lead Should be Used.