Cable Tray Separation and ITC-ER Cable Rating

[Stan Stephan]

Customer wants to install a PLTC/ITC (low voltage instrument) cable with Served Wire Armor (UL Listed) in cable tray in an industrial environment. Cable tray has some separations (about 18 inches) but trays are bonded. NEC Article 392.6 states "conductors from one tray to another can be installed if cable is not run a distance greater than 6 feet and the conductors are secured to the cable trays at the transitions and they are protected by guarding or by location from physical damage. Customer believes this cable is suitable for this installation. Local inspector wants cable to be ITC-ER listed. We believe ITC-ER is only required when distance outside of Tray or conduit etc is greater than 6 feet.

 

[rbalex]

Any cable wiring method permitted to be installed in a cable tray [Section 392.3 & Table 392.3(A)] has the benefit of 392.6; there is no restriction.

That said, I would be extremely cautious with single conductor applications. I know it isn?t your issue at the moment but, unless they are tightly secured in the trays and tightly bound in the transition, single conductor cables can react very violently under fault conditions.

 

[Smart $]

I agree with Bob...

However, you do have to comply with the latter part of that requirement, "...they shall be protected, by guarding or by location, from physical damage." Unfortunate for you, the inspector at his discretion determines whether or not you have complied with this part. You did not elaborate as to how you believe this is accomplished for your situation.