If my JB is already connected with the steel structure of the plant which is grounded to P.E. whether we require to again ground the JB with grounding wire or steel structure will serve the purpose.
Well diferent countries have diferent regulations, I.e. in the UK you would typically take a bond from your ground point inside the pannel to the actual steel frame, but in the USA you would be allowed to use one of the fixing bolts as long as it is tapped into the steel i believe.
It is allways good practice to bond metal objects likely to become energised and within touching distance of each other.(equipotential bond)
Since protective ground are connected internally in the main JB, has to be grounded properly. The structure earth will provide a high resistance over a period time. hence an independant earth wire of 14 gauge or better direct to the earth pit raiser bar from the junction box is strongly recommended.
JB Grounding
Re: JB Grounding
