Bonding, grounding protection?

[ELECTRICAL SYSTEM'S]

Installed a #4 THHN from building steal to a grounding bar for telecomunications cabinet. I sleeved the #4 through a piece of 3/4 conduit with plastic bushings at each end.
Question came up, does the conduit need to be bonded?

 

[SEO]

Yes if it is a ferrous metal enclosure bonding of both ends is required. Look at section 250.64 (E).

 

[infinity]

Does this really fall under Article 250 given it's intended use?

 

[ceb58]

The R56 standard require if you use metallic sleeve that it be bonded to the MGB on the outside and inside. I sleeve our communication buildings with carflex ( non-metallic flex) then I just seal the ends with silicon caulk

 

[erickench]

Yes if it is a ferrous metal enclosure bonding of both ends is required. Look at section 250.64 (E).

"Ferrous 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."

 

[infinity]

"Ferrous 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."

The question is does the code require this for a communication cabinet bond? Is the conductor an actual Article 250 GEC?

 

[cripple]

Bonding, and grounding protection?

Bonding, and grounding protection?

The NEC does require the metal raceways enclosing the grounding conductor to be bonded at both end.
800.100 (A) Grounding Conductor.
(6) Physical Protection. The grounding conductor shall be protected where exposed to physical damage. Where the grounding conductor is run in a metal raceway, both ends of the raceway shall be bonded to the grounding conductor or the same terminal or electrode to which the grounding conductor is connected.

810.58(A) Other Sections.
All grounding conductors for amateur transmitting and receiving stations shall comply with 810.21(A) through (K).

810.21(D) Mechanical Protection.
The grounding conductor shall be protected where exposed to physical damage. Where the grounding conductor is run in a metal raceway, both ends of the raceway shall be bonded to the grounding conductor or to the same terminal or electrode to which the grounding conductor is connected.

820.100 Cable Grounding.
(6) Physical Protection. The grounding conductor shall be protected where exposed to physical damage. Where the grounding conductor is run in a metal raceway, both ends of the raceway shall be bonded to the grounding conductor or the same terminal or electrode to which the grounding conductor is connected.
830.100(A) Grounding Conductor.
(6) Physical Protection. The grounding conductor shall be protected where exposed to physical damage. Where the grounding conductor is run in a metal raceway, both ends of the raceway shall be bonded to the grounding conductor or the same terminal or electrode to which the grounding conductor is connected.

 

[SG-1]

Does this really fall under Article 250 given it's intended use?

It falls under 250.64(E) because of the unintended consequences. Not bonding at both ends will roughly double the circuit impedance. The conduit acts as a choke.