UL Thermostat Wire Size: 500' Type: Reel Number of Conductors: 3 Gauge: 18

Type THRM Thermostat Wire is also called power limited circuit cable. Used as fixed wiring within commercial and industrial buildings for Class 2 power limited circuits such as thermostat, air conditioning controls, heat pumps, heating controls, bell and alarm systems, signal systems, intercom systems, and remote control. 18 AWG: Runs over 200 ft. where voltage is critical, where higher amperage capacity and equipment warranty require currents up to 8 AMPS. 20 AWG: Where slight voltage drops not a concern. Medium to long runs requiring good pulling strength for currents up to 4 Amps.