Low Voltage Cable & KO Bushings

[robthome]

Does the NEC require KO bushings to be installed to protect low voltage cable (specifically FPL cable for PLFA circuits) when installed free-air into metal boxes?

Thanks.

 

[peter d]

Re: Low Voltage Cable & KO Bushings

No, the NEC does not require them but it's a good idea to use them anyway to prevent shorts and ground faults, and it makes the installation look more professional. A box of 1/2" or 3/4" bushings doesn't cost more than $10 anyway.

[ August 24, 2005, 01:48 PM: Message edited by: peter d ]

 

[peter d]

Re: Low Voltage Cable & KO Bushings

I would also suggest you check your local codes. Local codes often have much stricter rules for fire alarms than the NEC. Furthermore, it is impossible to answer fire alarm questions in a general sense because fire alarm codes are wildly different even from city to city in in the same state.

Bottom line, when in doubt, consult your local Fire Marshall or AHJ.

 

[ryan_618]

Re: Low Voltage Cable & KO Bushings

I would say no, since the box isn't even required.

 

[pierre]

Re: Low Voltage Cable & KO Bushings

Take a look at these references:

"760.3 Locations and Other Articles. Circuits and equipment shall comply with 760.3(A) through (F). Only those sections of Article 300 referenced in this article shall apply to fire alarm systems."

"760.52 Wiring Methods and Materials on Load Side of the PLFA Power Source. Fire alarm circuits on the load side of the power source shall be permitted to be installed using wiring methods and materials in accordance with either
760.52(A) or (B)."


"(B) PLFAWiring Methods and Materials. Power-limited fire alarm conductors and cables described in 760.71 shall be installed as detailed in 760.52(B)(1), (2), or (3) of this
section. Devices shall be installed in accordance with 110.3(B), 300.11(A), and 300.15."

 

[wannabe]

Re: Low Voltage Cable & KO Bushings

Depends what "hack" is terminating.

 

[wannabe]

Re: Low Voltage Cable & KO Bushings

DO A GOOD JOB Regardless!