18/2 Riser Security Alarm Cable - CMR/CL3R Rated, 7 Strand Copper, 1000ft Gray

This is the two-conductor riser cable for the power runs of a security or low-voltage system: two 18 AWG stranded bare copper conductors, black and red, under a gray PVC jacket listed CL3R under NEC Article 725 for Class 3 power-limited circuits (and by the code's substitution rules for Class 2 as well), CMR under Article 800 for communications, and FPLR under Article 760 for power-limited fire alarm circuits, so the one cable can feed a door strike, a siren, a speaker, a power supply, or a 12 V or 24 V accessory, and run up a riser shaft, through a wall, or across a ceiling that isn't a return-air plenum. 18 AWG is the gauge for anything that draws real current, with about half the loop resistance of 22 AWG, and the 7-strand conductors bend around a ceiling and land in a terminal block more easily than solid wire.

CL3R and CMR cover the vertical runs between floors of a multi-story building and every ordinary in-wall and in-ceiling run that isn't a plenum. It's unshielded, which is the right construction for power, strike, and speaker runs where there's no data signal to protect, and it keeps the cable slim and the price down. The cable is ETL Listed and RoHS compliant, and it comes in a 1000 ft pull box with sequential footage marks on the jacket.

Features

• Riser rated three ways. CL3R under NEC Article 725, CMR under Article 800, and FPLR under Article 760, so it's listed for riser shafts, vertical runs between floors, and general in-wall and in-ceiling use on security, control, communications, and fire alarm circuits alike, and the CL3R listing covers Class 2 circuits under the code's substitution rules.
• Two 18 AWG stranded bare copper conductors. About half the loop resistance of 22 AWG, for strike, siren, and power-supply runs, on 7-strand conductors that bend around a ceiling and seat in a terminal block without fighting.
• Black and red. The standard pair coding for polarity on a DC power or alarm circuit.
• Unshielded. The right construction for power, strike, and speaker circuits, and the easier one to terminate.
• PVC insulation and jacket. A 0.010 in insulation wall on each conductor and a 0.015 in jacket, flexible and easy to strip.
• Gray jacket. Reads as general-purpose low-voltage in a wall or a tray, and stays distinct from red fire alarm and blue data cable.
• 300 V, 75 °C. The ratings a Class 2, Class 3, or power-limited fire alarm circuit calls for.
• 4.09 mm outer diameter. Slim enough to bundle by the dozen and fish through a wall or a tight ceiling.
• ETL Listed, RoHS compliant.
• 1000 ft pull box. Sequential footage marks on the jacket; pays out from the box without a spool stand, and the box stacks in a van.

Where It Fits

It suits electric strikes and maglocks on access control doors, sirens, strobes, and sounders on an alarm output, 12 V and 24 V power from a supply to keypads, readers, and auxiliary devices, 70 V and 8 Ω paging and background music speakers in a ceiling, thermostat and damper control pairs, power-limited fire alarm circuits that call for a stranded pair, and any two-conductor low-voltage run through the walls and risers of a home, apartment building, office, or store where the ceiling space isn't a return-air plenum.

Good to Know

Run the voltage-drop calculation on any pair that carries power. An 18 AWG pair is about 13 ohms per 1000 ft round trip, so a 12 V strike drawing 0.5 A at the far end of a 200 ft run loses about 1.3 V, and a 24 V siren drawing 1 A at 300 ft loses about 3.9 V; for a heavier load or a longer run, step up to 16 AWG or move the power supply closer. Speaker runs are figured on impedance and wattage rather than current, and 18 AWG is comfortable for 70 V distributed systems over several hundred feet. A maglock is a continuous load, so size the run for its holding current and the supply's low-battery voltage, not just nominal. Keep the circuits in their classes: Class 2 and Class 3 circuits can use this cable, but a Class 1 circuit can't, and the NEC requires power-limited wiring to stay separated from power conductors in raceways and boxes. Stranded conductors want a ferrule or a proper fold-back before they go under a screw terminal; a stray strand is the short that takes a zone into trouble. CL3R and CMR cover risers and general use but not return-air plenums; a run through a plenum ceiling needs the plenum 18/2. The jacket isn't UV stabilized or rated for wet locations or burial, so an outdoor siren or contact should be fed through conduit or from a cable rated for it.

Specifications