Carrier 42 SERIES Application Data

Two-Pipe Thermostat, Model TF103 — This single-pole, double-throw (SPDT) thermostat has snap-action con-tacts. The standard temperature range is 60 - 90 F.Four-Pipe Thermostat, Model TH104 — With thisthermostat, heating and cooling are sequenced (automaticchangeover) with 6 degree separation between HEATINGON and COOLING ON. The standard temperature range is60 - 90 F.Thermostat Electrical Data(Pilot Duty — 125 VA at 120-277 v)ITEM VOLTS FLA LRATF103andTH104120 16 80240 12 60277 10 50Automatic Changeover (Summer-Winter Switch) —The automatic-changeover thermostat is a single-pole double-throw (SPDT) thermal switch in a moistureproof and dust-proof enclosure. Thermostat mechanism and lead ends arehermetically sealed in a polypropylene enclosure with ep-oxy resin. Device clamps on coil supply pipe with end snap-onclip.The set point temperatures are factory set. When watertemperature rises above 80 F (approximately), the thermo-stat switches to the winter cycle. When water temperaturedrops below approximately 70 F, the thermostat switches tothe summer cycle. Switch reset is automatic.STEMCO416-79L80 8220AUTOMATIC CHANGEOVER (Summer-Winter) SWITCH13