Where to bond, or not to bond

[Journeyman Elec]

I need clarification. I have a transformer with a five wire system (3 phase conductors, a grounded conductor, and a grounding conductor) going to a MDP. Can the transformer and the MDP both be bonded?

 

[roger]

Can the transformer and the MDP both be bonded?

Did you mean EGC when you said "grounding conductor"?

As to your question of bonding the neutral at both locations, you can only do that if there will never be any conductive path that may occur as to provide a parallel current path of the grounded (neutral) conductor. See 250.30(A)(1) Exception 2

Roger

 

[kwired]

Did you mean EGC when you said "grounding conductor"?

As to your question of bonding the neutral at both locations, you can only do that if there will never be any conductive path that may occur as to provide a parallel current path of the grounded (neutral) conductor. See 250.30(A)(1) Exception 2

Roger

If you are permitted to do so and do bond at both points the "fifth wire" is not needed and really not allowed as it will become a parallel to the neutral. After the MDP the separation of grounded and grounding is necessary.

 

[Journeyman Elec]

I did in fact mean EGC for grounding conductor.