WIRING DIAGRAM NOTES:
1. Carrier thermostat wiring diagrams are only accurate for model numbers TSTAT _ _ _ _ _ _ _.
2. Wiring must conform to NEC or local codes.
3. Connect 24-v field wiring to factory-provided stripped leads.
4. Thermostats are factory configured with 5-minute compressor cycle protection and 4 cycles per hour limit. See thermostat Installation
Instructions for details.
5. To stage electric resistance heat, consult outdoor thermostat Installation Instructions.
6. Terminals marked with an * may not be present on equipment.
7. Underlined letter on dual terminal indicates its usage.
For example: O/W2 means O is energized in cooling mode.
8. Refer to fan coil Installation Instructions for features and additional wiring information.
9. Programmable model 2S, when used in heat pump installations (Switch C OFF), uses O/W2 to control reversing valve.
10. Non-programmable model 2S, when used in heat pump installations (Jumper R19 NOT cut), uses O/W2 to control reversing valve.
11. Select the ZONE position on 2-speed heat pump control board. In heating mode, this allows Y1 to control low-speed compressor
operation and Y2 to control high-speed compressor operation.
12. Furnace must control its own second-stage operation via furnace control algorithm. Refer to furnace Installation Instructions for proper
setup.
13. To activate dehumidify function on FK4C or 40FKA, remove J1 jumper at fan coil control board.
14. Heat pump MUST have a high-pressure switch for dual fuel applications.
15. Outdoor air temperature sensor must be attached in all dual fuel applications.
16. Thermidistat Dip Switch 1 should be set in the ON position for heat pump installations.
17. Thermidistat Dip Switch 2 should be set in the ON position for 2-speed compressor operation.
18. Thermidistat Configuration Option No. 10 "Dual Fuel Selection" must be turned on in all dual fuel applications.
19. To activate dehumidify feature on current style 58MVP variable-speed furnaces, a pilot duty, 24-v relay must be used.
20. To activate dehumidify feature on current style 58UHV,58UXV variable-speed 80% non-condensing furnaces, disconnect green
(dehum) wire from G on furnace control board and connect to dehumidify terminal dhu on thermidistat.
21. See Table 3—Airflow Selection for 58UHV,58UXV Furnaces.
22. See Table 4—Airflow Selection for 58MVP Furnaces.
23. See Table 5—Airflow Selection for FK4C or 40FKA Fan Coil.
24. Select Furnace Interface Option, Balance Point, and Defrost Time on 2-speed heat pump control board.
25. Thermidistat controls dual fuel operation; do not select Furnace Interface Option on 2-speed heat pump control board.
26. Dual fuel thermostat Dip Switch D should be set in the ON position for 2-speed compressor operation. This thermostat controls dual
fuel operation; do not select Furnace Interface Option on 2-speed heat pump control board.
LEGEND
24-V FACTORY WIRING
24-V FIELD WIRING
FIELD SPLICE CONNECTION
RELAY SPDT, PILOT DUTY
24-V COIL (HN61KK324)
OR EQUIVALENT
HUMIDISTAT, OPENS ON
HUMIDITY RISE (HL38MG026)
AIRFLOW SELECTOR
R1
H
AFS
A97466
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