User Guide
Page 15
... indicating operation with EM. C3-Stage 3 Cooling. HEAT switching). HT.-HEAT-OFFCOOL switching). Heat changeover valve-operates on some heat pumps. H3-Stage 3 Heating. Each schematic indicates switch operation by a mercury switch that makes on a temperature rise (auto changeover). H2-Stage 2 Heating. C2-Stage 2 Cooling. Cool changeover valve-operates on a temperature fall (auto changeover). The thermostat automatically changes between heat and cool modes as follows: Auto changeover...
... indicating operation with EM. C3-Stage 3 Cooling. HEAT switching). HT.-HEAT-OFFCOOL switching). Heat changeover valve-operates on some heat pumps. H3-Stage 3 Heating. Each schematic indicates switch operation by a mercury switch that makes on a temperature rise (auto changeover). H2-Stage 2 Heating. C2-Stage 2 Cooling. Cool changeover valve-operates on a temperature fall (auto changeover). The thermostat automatically changes between heat and cool modes as follows: Auto changeover...