Carrier 120/C Series Installation, Start-Up, Operating And Service And Maintenance Instructions page 26

1. Heat pump MUST have a high pressure switch for dual fuel applications.
2. Refer to outdoor equipment Installation Instructions for additional information and setup procedure.
3. Outdoor Air Temperature Sensor must be attached in all dual fuel applications.
4. Dip switch No. 1 on Thermidistat should be set in OFF position for air conditioner installations. This is factory default.
5. Dip switch No. 1 on Thermidistat should be set in ON position for heat pump installations.
6. Dip switch No. 2 on Thermidistat should be set in OFF position for single-speed compressor operation. This is factory default.
7. Dip switch No. 2 on Thermidistat should be set in ON position for two-speed compressor operation.
8. Configuration Option No. 10 "Dual Fuel Selection" must be turned ON in all dual fuel applications.
9. NO connection should be made to the furnace HUM terminal when using a Thermidistat.
10. The RVS Sensing terminal "L" should not be connected. This is internally used to sense defrost operation.
11. DO NOT SELECT the "FURNACE INTERFACE" or "BALANCE POINT" option on the two-speed heat pump control board. This is
controlled internally by the Thermidistat/Dual Fuel Thermostat.
12. Dip switch D on Dual Fuel Thermostat should be set in OFF position for single-speed compressor operation. This is factory default.
13. Dip switch D on Dual Fuel Thermostat should be set in ON position for two-speed compressor operation.
Notes For Figures 26-32
26