transformer ground(raceway)

[elect36]

Some one brought this to my attention and I never new this. Is it true that a transformer inside a building-just say you are installing a 208y panel from 480 and you set your transformer- the building steel ground raceway must be in p.v.c.? They said that with any metal raceway it produces some sort of induction or something of that nature in the metal conduit. He read this out of a grounding book he had.

 

[peter d]

Re: transformer ground(raceway)

Running the GEC in PVC is certainly the easier way to do it.

You are permitted to use metal raceway for the GEC. However, the raceway must be bonded at both ends with the same size conductor as the GEC.

Sorry that I don't have a code reference; my code book is in another state right now. (one of the 50 states that is, not a state of confusion.

[ July 10, 2005, 12:40 PM: Message edited by: peter d ]

 

[infinity]

Re: transformer ground(raceway)

If the ground is installed in a ferrous raceway (steel) than it must be bonded to the EGC at both ends to prevent induction. Take a look at 250.64(E).

 

[iwire]

Re: transformer ground(raceway)

I agree with Peter, PVC is just an easer way to cope with GECs (all GECs not just SDS ones)

You are free to run the GEC in a steel raceway with the additional requirement of bonding the GEC to the raceway at each end.

250.64 (E) Enclosures for Grounding Electrode Conductors. Metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. Metal enclosures that are not physically continuous from cabinet or equipment to the grounding electrode shall be made electrically continuous by bonding each end to the grounding electrode conductor. Where a raceway is used as protection for a grounding electrode conductor, the installation shall comply with the requirements of the appropriate raceway article.