National Electrical Code Tips: Article 760, Fire Alarm Systems, Part 7

Understanding the listing requirements of fire alarm circuit cables can help you make sense of the cable alphabet soup. Here are some highlights from Part IV of Article 760.

1. Part IV, Listing Requirements, consists of two Sections: 760.176 and 760.179. And they are both pretty long, as far as sections go.
   
2. 760.176 provides the requirements for the listing and marking of NPLFA cables.
   
3. 760.179 provides the requirements for the listing and marking of PLFA cables (and for insulated continuous line-type detectors).
   
4. Table 760.154 shows the permitted applications for listed PLFA cables in buildings. There's not an equivalent table for NPLFA cables.
   
5. Table 760.154(A) shows the permitted cable substutitions for Cable Type FPLP, FPLR, and FPL. Type CMP can substitute for any of these.
   
6. Table 760.176(G) explains the meaning of cable markings NPLFP, NPLFR, and NPLF. The equivalent Table for power-limited, 760.176(I), was removed with the 2023 revision. Make sure you NEVER confuse NPLFP with NPLFR.
   
7. NPLFA conductors must be copper [760.176(A)]. While you may be permitted to get away with using aluminum in other parts of your fire alarm system or even premises wiring, it's a bad engineering decision to do so. The aluminum conductor people hate it when I say that, but the physics are what they are. Go with copper, accept no substitutes.
   
8. Text new with the 2014 revision provides requirements for Circuit Integrity (CI) cables and it's been modified a bit since that introduction. Among the requirements, CI cables can be installed only in a raceway where specifically listed and marked as part of an electrical circuit protective system [760.176(F)]. These requirements were heavily revised with the 2023 revision.
   
9. And text new with the 2014 revision provides requirements for the electrical circuit protective systems just mentioned. Among those, the hourly rating must be printed on the outer jacket of the cable [760.176(G)].
   
10. Insulated continuous line-type fire detectors, mentioned earlier, got scant coverage prior to the 2023 revision. Now 760.179 is filled out with (A) through (D).