Bonding vs. grounding of conduit w/ class III

[Unforgiven]

I have inspected an installation of 1 1/4" EMT with a couple of large J boxes being used as a raceway for class III wiring serving a ceiling mounted projector. Conduit have been joined together at the J boxes using plastic bushing rings instead of for example an insulated throat bushing with a lock ring.

All metal raceways and enclosures are required to be mechanically joined and electrically continuous per NEC Article 300.10.

The conduit as installed with plastic bushings instead of lock rings does not adequately bond the conduit to the boxes to satisfy the requirement of 300.10.

However, the 2005 NEC Article 250.86 (not yet adopted in my jurisdiction) provides an exception for raceways and enclosures with conductors operating at less than 50V ( Mike Holt "Understanding the National Electrical Code" Volume 1). This seems inconsistent since water piping and every other metal system in the building has to be bonded (NEC Article 250.104 (B) - requires all metal piping within a building to be bonded)... but conduit enclosing low voltage conductors does not?

Am I incorrectly interpreting the new 250.86 as releasing Class III wiring enclosures from the grounding and bonding requirements?

 

[tom baker]

250.86 does not apply and it does not have the term Class III.
If you are referring to an Art 725 Class II wiring system, then chapter 7, per 90.3 can modify the rules of Chapter 1-4, and most likely won't require bonding. But can you determine what type of wiring you are installing?