Please take a close look at this picture, and identify in your minds, the pieces of the puzzle that comprise the equipment grounding conductor.

I would like to use this thread to identify some of the important parts of the grounding system in an installation, so please add your comments accordingly.

I am not interested in a wire here, my interest is with the recognized equipment grounding conductors permitted by 250.118.

Here we have one and it is Rigid Metal Conduit.

The "T" Condulet is defined as a "conduit body" and the subject of the continuity is where I want to begin.

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The EGC originates from the top RMC connected to a panelboard, and the others to the right, and bottom continue the circuit raceway for lighting in stairwells in a parking garage.

The connections at the beginning of the run and at this conduit body are very important and if they are not "wrench" tight may not ensure that 300.10 is complied with.

Question 1: Does the "T" serve to bond the right and bottom raceways?

Question 2: Should the NEC call for at least 5 threads fully engaged here as in hazardous (classified) locations?

Question 3: Could we live with a term to read as follows" "... Equipment grounding and bonding conductor"?

Think about the couplings, and all fittings in a run of RMC, say 200 feet long, do the fittings act to bond the EGC's together?

We may have to wait until 2008 for any changes related to the proposed change from EGC to EBC, so let's start here.

Joe Tedesco, NEC Consultant