These low voltage smoke detectors and carbon monoxide detectors are designed to be used with security alarm systems. We stock both 2 wire smoke detectors and 4 wire smoke detectors. 2 Wire Smoke Detectors use the same pair of wires to provide power from the alarm system as well as signalling in case of a fire. 4 Wire Smoke Detectors use a pair of wires for power and a pair of wires for a zone connection to the alarm system. Low voltage CO detectors are typically 4 wire devices with 2 wire used for power and 2 for the zone alarm signal. They may have additional relay outputs as well.
