NEC 760 - Fire Alarm Cable Type

[mshopkins]

Is it permissible to use THHN wire for power-limited fire alarm circuits in metal raceway? Is this considered an NPLFA wiring method and therefore OK?

 

[tom baker]

Re: NEC 760 - Fire Alarm Cable Type

760.52 refers to 760.25 which states a chapter 3 wiring method shall be used, I would say yes
I don't do many fire alarm systems, lets see who else posts.

 

[peter d]

Re: NEC 760 - Fire Alarm Cable Type

Yes, it is.

 

[peter d]

Re: NEC 760 - Fire Alarm Cable Type

Originally posted by mshopkins:
Is it permissible to use THHN wire for power-limited fire alarm circuits in metal raceway? Is this considered an NPLFA wiring method and therefore OK?

You wouldn't happen to be working in America's smallest state, would you?

The reason I ask is this:

From RI Fire Safety Code

(Add) 13.8.10.6.2.1
All conductors shall be minimum #16 gauge solid copper, type thhn, thwn or tfn. All
wiring shall be run continuously from device to device.

 

[ryan_618]

Re: NEC 760 - Fire Alarm Cable Type

While I agree with Tom, I think this is the more accurate code section to answer the question with. Granted, a chapter 3 wiring method is permitted to be used, but that doesn't tell me about conductor types, which is the question.

760.27 NPLFA Circuit Conductors.
(A) Sizes and Use. Only copper conductors shall be permitted to be used for fire alarm systems. Size 18 AWG and 16 AWG conductors shall be permitted to be used, provided they supply loads that do not exceed the ampacities given in Table 402.5 and are installed in a raceway, an approved enclosure, or a listed cable. Conductors larger than 16 AWG shall not supply loads greater than the ampacities given in 310.15, as applicable.
(B) Insulation. Insulation on conductors shall be suitable for 600 volts. Conductors larger than 16 AWG shall comply with Article 310. Conductors 18 AWG and 16 AWG shall be Type KF-2, KFF-2, PAFF, PTFF, PF, PFF, PGF, PGFF, RFH-2, RFHH-2, RFHH-3, SF-2, SFF-2, TF, TFF, TFN, TFFN, ZF, or ZFF. Conductors with other types and thickness of insulation shall be permitted if listed for non?power-limited fire alarm circuit use.

Because above section refers the user to Article 310, and THHN is listed in Table 310.13, I would say yes

 

[mshopkins]

Re: NEC 760 - Fire Alarm Cable Type

Gentlemen,

Thanks for your help. That's prety much what I assumed. It's just confusing whether a "wiring method" encompasses wire types as well.

No, I am not in Rhode Island - they seem to have made the issue clear, though.

Thanks again