No one line diagram, need some help please

[918electrician]

I have a pad mount transformer that I ran a 4 in conduit from to a 600 amp fusible disconnect to a 400 amp motor. There are parallel lugs for 300kcmil wire. The motor obviously does not need a neutral. Everything is 480v. My question is do I run the same size grounded conductor from the transformer to the disconnect? Also should it be Grey or Green? What about the wire from the disconnect to the motor?

 

[kwired]

I have a pad mount transformer that I ran a 4 in conduit from to a 600 amp fusible disconnect to a 400 amp motor. There are parallel lugs for 300kcmil wire. The motor obviously does not need a neutral. Everything is 480v. My question is do I run the same size grounded conductor from the transformer to the disconnect? Also should it be Grey or Green? What about the wire from the disconnect to the motor?

Is the pad mount utility owned/controlled and you are dealing with service conductors from it, or is it customer owned and a separately derived system making the secondary conductors feeders instead of service conductors? Answer to this will make a difference on which code section applies for selecting size as well as what color it should be.

 

[Jraef]

Is the pad mount utility owned/controlled and you are dealing with service conductors from it, or is it customer owned and a separately derived system making the secondary conductors feeders instead of service conductors? Answer to this will make a difference on which code section applies for selecting size as well as what color it should be.

I agree, other than the fact that I fail to see a scenario wherein the EGC is anything other than green. Gray is only an option for grounded circuit conductors, i.e. "neutral".

GEC = Grounding Electrode Conductor; the wire from the grounding electrode (ground rod) to the service entrance. Green or bare copper.

EGC = Equipment Grounding Conductor; the green (or bare) conductor that is connecting your pieces of equipment to ground for safety, NOT EVER intended to be a Current Carrying Conductor.

Neutral = A grounded circuit conductor in a single phase or 3 phase 4 wire system, considered a Current Carrying Conductor, ALWAYS insulated and identified as white, grey or have white stripes / tape. Note that identification of a grounded conductor in a 3 wire 3 phase system is different, because although grounded, it is not neutral.