I am a EE trying to decipher the code on bonding of metallic raceways in Class II Div 2 areas. We do NOT use the raceway as the equipment grounding conductor. I am also looking at NEC 2011. System is agricultural 480/277V.
502.30 - Grounding and Bonding, Class II Div 1 & 2. (A) says the locknut-bushing and double-locknut types of contact shall not be depended on for bonding purposes, but bonding jumpers with proper fittings or other approved means of bonding shall be used.
250.100 Bonding in Hazardous (Classified) Locations - this says, in summary, to use bonding methods specified in 250.92(B)(2) through (B)(4), One or more of these bonding methods shall be used whether or not equipment grounding conductors of the wire type are installed.
(B)(2) - connections utilizing threaded couplings or threaded hubs on enclosures if make up wrenchtight.
(B)(3) - threadless couplings and connectors if made up tight for metal raceways.
(B)(4) - other listed devices, such as bonding type locknuts, bushings or bushings with bonding jumpers
So am I correct in requiring a grounding bushing for our metal raceways from the classified area back to where it terminates to the grounding electrode conductor or aux grounding electrode?