... models,Advanced detection and discrimination algorithm,Easy installation Fire Alarm,Conventional Heat Detector,Two or four-wire models,Advanced detection ... : Ceiling spacing: 50-feet rating for heat sensor Start-up current: 70mA maximum Alarm impedance: 100 ohms +3V maximum, 560 ... : less than 1V Reset time: less than one second Alarm indicator: continuously emitting red light Temperature range: -10 to ...