Re: Grounding bushings
The purpose of a grounding bushing is to provide a bonding means between the enclosure and a metallic conduit system, while also providing an insulated collar to protect wires and conductors entering and exiting the raceway.
Installation should be made by manufacturers instructions and at locations as required by the NEC or at points where certainty of metallic continuity is desired. See section V of the 2002 NEC.
