trailer mounted generator

[Mike Speedy]

I am a maintenance electrician at a mine in Montana. We are a surface metal/nonmetal mine. I currently hold a State of Montana Journeyman's license. i have held this license since 2005. As you know we are inspected by MSHA for safety, not OSHA. I am currently having a dispute with an MSHA inspector. We have a few portable light plants that move quite often. The inspector is questioning why we are not driving 2 ground rods and grounding the light plant every time we move it. The manufacture's recommendation is the unit will be "well grounded per applicable regulations". At the mine I have two regulations I follow: 30 CFR and the NEC. The inspector couldn't show me where the CFR regulations specifically call for the light plant to be grounded. Article 250.34 specifically says if the conditions are met, it doesn't need a grounding electrode. I asked the MSHA inspector what purpose the ground rod served. The reply I was given was that if someone was working on the light plant in a lightning storm and the light plant was struck by lightning, the ground rod would dissipate the lightning strike. I know better. Am I interrupting the code correctly? Is there any other info that can clear this up for both the inspector and myself? Thank you.

 

[tortuga]

I think your likely correct you do not have to 'ground' them to a GEC, but you may need to provide proof of an alternate means of shock protection.
5ma GFCI protection at the breaker (easiest), a system of double insulation (part of the product listing) or fail-safe ground monitor are examples.
See
30 CFR § 56.12034 Guarding around lights.
Portable extension lights, and other lights that by their location present a shock or burn hazard, shall be guarded.
30 CFR § 56.12027 - Grounding mobile equipment.
30 CFR § 56.12035 Weatherproof lamp sockets