5, as applicable. Derating factors shall not be applied. Overcurrent protection shall not exceed 7 amperes for No. 18 conductors and

Derating factors shall not be applied. Overcurrent protection shall not exceed 7 amperes for No. 18 conductors and 10 amperes for No. 16. Exception: Where other articles of this Code permit or require other overcurrent protection. 760-13. Location of Overcurrent Devices. Overcurrent devices shall be located at the point where the conductor to be protected receives its supply. Exception No. 1: Where the overcurrent device protecting the larger conductor also protects the smaller conductor. Exception No. 2: Transformer secondary conductors. Nonpowerlimited fire protective signaling circuit conductors supplied by the secondary of a single-phase transformer having only a 2-wire (single voltage) secondary shall be permitted to be protected by overcurrent protection provided by the primary (supply) side of the transformer, provided the protection is in accordance with Section 450-3 and does not exceed the value determined by multiplying the secondary conductor ampacity by the secondary-to-primary transformer voltage ratio. Transformer secondary conductors other than 2-wire shall not be considered to be protected by the primary overcurrent protection. 760-14. Wiring Method. Wiring installation shall be in accordance with the appropriate articles in Chapter 3. Exception No. 1: As provided in Sections 760-15 through 760-18. Exception No. 2: Where other articles of this Code require other methods. 760-15. Conductors of Different Circuits in Same Cable, Enclosure, or Raceway. Class 1 and nonpower-limited fire protective signaling circuits shall be permitted to occupy the same cable, enclosure, or raceway without regard to whether the individual circuits are alternating current or direct current, provided all conductors are insulated for the maximum voltage of any conductor in the enclosure or raceway. Power-supply and fire protective signaling circuit conductors shall be permitted in the same cable, enclosure, or raceway only where connected to the same equipment. 760-16. Copper Conductors. (a) Types, Sizes, and Use. Only copper conductors shall be permitted to be used for fire protective signaling systems. Conductors of Nos. 18 and 16 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 70-770 NATIONAL ELECTRICAL CODE or a listed cable. Conductors larger than No. 16 shall not supply loads greater than the ampacities given in Section 310-15, as applicable. (b) Insulation. Insulation on conductors shall be suitable for 600 volts. Conductors larger than No. 16 shall comply with Article 310. Conductors in sizes No. 18 and 16 shall be Type KF-2, PF, PGF, RFH-2, RFHH-2, RFHH-3, SF-2, TF, TFN, or ZF. Conductors with other types and thickness of insulation shall be permitted if listed for nonpower-limited fire protective signaling circuit use. (FPN): For application provisions, see Table 402-3. (c) Conductor Materials. Conductors shall be solid or bunch-tinned (bonded) stranded copper. Exception No. 1: Stranded copper with a maximum of 7 strands for Nos. 16 and 18 shall be permitted. Exception No. 2: Stranded copper with a maximum of 19 strands for Nos. 14 and larger shall be permitted. Exception to (b) and (c): Wire Types PAF and PTF shall be permitted only (482°F). for high-temperature applications between 90°C (194°F) and 250°C 760-17. Multiconductor Nonpower-Limited Fire Protective Signaling Circuit Cables for Circuits Operating at 150 Volts or Less. Multiconductor nonpower-limited fire protective signaling circuit cables that meet the requirements of (a) through (e) below shall be permitted to be used on fire protective signaling circuits operating at 150 volts or less. (a) Fire Resistance of Cables Within Buildings. Multiconductor nonpower-limited fire protective signaling circuit cables installed as wiring within buildings shall be listed as being resistant to the spread of fire in accordance with sections (b) and (c) below. (b) Listing and Markings. Multiconductor nonpower-limited fire protective signaling circuit cables in a building shall be listed as being suitable for the purpose, and cables shall be marked in accordance with Table 760-17(b). Table 760-17(b). Cable Markings Cable Marking Type Reference NPLFP nonpower-limited fire protective Sections 760-17(c)(4) signaling circuit plenum cable and 760-17(e)(2) NPLFR nonpower-limited fire protective Sections 760-17(c)(5) signaling circuit riser cable and 760-17(e)(3) NPLF nonpower-limited fire protective Sections 760-17(c)(6) signaling circuit cable and 760-17(e)(4) (FPN No. 1): See the referenced sections for listing requirements and permitted uses. (FPN No. 2): Cable types are listed in descending order of fire resistance rating. ARTICLE 760 - FIRE PROTECTIVE SIGNALING SYSTEMS 70-771 (c) Listing Requirements. Nonpower-limited fire protective signaling circuit cables shall be listed in accordance with (1) through (3) below and, depending on the type, (4) through (6) below. (1) Conductor Materials. Conductors shall be solid copper or bunchtinned (bonded) stranded copper. Exception No. 1: Stranded copper with a maximum of 7 strands for No. 16 and No. 18 shall be permitted. Exception No. 2: Stranded copper with a maximum of 19 strands for Nos. 14 and larger shall be permitted. (2) Sizes and Number. The cables shall have two or more No. 18 or larger conductors. (3) Ratings. Each insulated conductor of the cable shall have a voltage rating of not less than 300 volts. The combination of the insulated conductors and the cable jacket shall have a voltage rating of not less than 600 volts. (4) Type NPLFP. Type NPLFP nonpower-limited fire protective signaling plenum cable shall be listed as being suitable for use in other space used for environmental air as described in Section 300-22(c) and shall also be listed as having adequate fire-resistant and low-smokeproducing characteristics. (FPN): One method of defining low-smoke-producing cable is by establishing an acceptable value of the smoke produced when tested in accordance with the Test for Fire and Smoke Characteristics of Wires and Cables, NFPA 262-1990 (ANSI) to a maximum peak optical density of 0.5 and a maximum average optical density of 0.15. Similarly, one method of defining fire-resistant cables is by establishing maximum allowable flame travel distance of 5 feet (1.52 m) when tested in accordance with the same test. (5) Type NPLFR. Type NPLFR nonpower-limited fire protective signaling riser cable shall be listed as being suitable for use in a vertical run in a shaft or from floor to floor and shall also be listed as having fire-resistant characteristics capable of preventing the carrying of fire from floor to floor. (FPN): One method of defining fire-resistant characteristics capable of preventing the carrying of fire from floor to floor is that the cables pass the Test for Flame Propagation Height of Electrical and Optical-Fiber Cables Installed Vertically in Shafts, ANSI/UL 1666-1986. (6) Type NPLF. Type NPLF nonpower-limited fire protection signaling cable shall be listed as being suitable for general-purpose fire alarm use, with the exception of risers, ducts, plenums, and other space used for environmental air, and shall also be listed as being resistant to the spread of fire. (FPN): One method of defining resistant to spread of fire is that the cables do not spread fire to the top of the tray in the "Vertical-Tray Flame Test" in the Reference Standard for Electrical Wires, Cables and Flexible Cords, ANSI/UL 1581-1985. Another method of defining resistant to the spread of fire is for the damage (char length) not to exceed 4 feet 11 inches (1.5 m) when performing the CSA "Vertical Flame Test - Cables in Cable Trays," as described in Test Methods for Electrical Wires and Cables, CSA C22.2 No. 0.3-M-1985. 70-772 NATIONAL ELECTRICAL CODE (d) Wiring Method. Multiconductor nonpower-limited fire protective signaling circuit cables described in Section 760-17(a) shall be installed as follows: (1) In raceway or exposed on surface of ceiling and sidewalls or "fished" in concealed spaces. Where installed exposed, cables shall be adequately supported and terminated in approved fittings and installed in such a way that maximum protection against physical damage is afforded by building construction such as baseboards, door frames, ledges, etc. Where located within 7 feet (2.13 m) of the floor, cables shall be securely fastened in an approved manner at intervals of not more than 18 inches (457 mm). (2) In metal raceway or rigid nonmetallic conduit where passing through a floor or wall to a height of 7 feet (2.13 m) above the floor unless adequate protection can be afforded by building construction such as detailed in (1) above, or unless an equivalent solid guard is provided. (3) In rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, or electrical metallic tubing where installed in hoistways. Exception: As provided for in Section 620-21, Exception Nos. 1 and 2 for elevators and similar equipment. (e) Applications of Listed Nonpower-Limited Fire Protective Signaling Circuit Cables. The use of nonpower-limited fire protective signaling circuit cables shall comply with (1) through (4) below. (1) Ducts and Plenums. Multiconductor nonpower-limited fire protective signaling circuit cables shall not be installed exposed in ducts or plenums. See Section 300-22(b). (2) Other Spaces Used for Environmental Air. Cables installed in other spaces used for environmental air shall be Type NPLFP. Exception No. 1: Types NPLF and NPLFR cables installed in compliance with Section 300-22(c). Exception No. 2: Other wiring methods in accordance with Section 300-22(c) and conductors in compliance with Section 760-16(c). (3) Riser. Cables installed in vertical runs and penetrating more than one floor or cables installed in vertical runs in a shaft shall be Type NPLFR. Floor penetrations requiring Type NPLFR shall contain only cables suitable for riser or plenum use. Exception No. 1: Type NPLF or other cables specified in Chapter 3 that are in compliance with Section 760-16(c) and encased in metal raceway. Exception No. 2: Type NPLF cables located in a fireproof shaft having firestops at each floor. (FPN): See Section 300-21 for firestop requirements for floor penetrations. (4) Other Wiring Within Buildings. Cables installed in building locations other than the locations covered in (1), (2), and (3) above shall be Type NPLF. Exception No. 1: Chapter 3 wiring methods with conductors in compliance with Section 760-16(c). Exception No. 2: Type NPLFP or Type NPLFR cables shall be permitted. ARTICLE 760 - FIRE PROTECTIVE SIGNALING SYSTEMS 70-773 760-18. Number of Conductors in Cable Trays and Raceways, and Derating. (a) Nonpower-Limited Fire Protective Signaling Circuits and Class 1 Circuits. Where only nonpower-limited fire protective signaling circuit and Class 1 circuit conductors are in a raceway, the number of conductors shall be determined in accordance with Section 300-17. The derating factors given in Article 310, Note 8(a) of Notes to Ampacity Tables of 0 to 2000 Volts shall apply if such conductors carry continuous load in excess of 10 percent of the ampacity of each conductor. (b) Power-Supply Conductors and Fire Protective Signaling Circuit Conductors. Where power-supply conductors and fire protective signaling circuit conductors are permitted in a raceway in accordance with Section 760-15, the number of conductors shall be determined in accordance with