HVACopediaCarrier · Heat pump · Cooling
Non-communicating heat pump: cooling with 5-minute compressor delay (HK32EA003/008)
What happens, in order
- Control powers up (24 V between R and C) and a 5-minute timer starts; compressor will not start until it expires
- Thermostat makes R-O, R-Y and R-G on a call for cooling
- R-O shifts the reversing valve to cooling
- R-Y feeds the safeties and energizes terminal T1 on the board
- If the compressor has been off 5 min (or power was off 5 min), fan relay OF2 and T2 energize, closing the contactor to start outdoor fan and compressor
- Thermostat satisfied R-Y drops, compressor and fan stop, and the 5-minute timer restarts
- With Carrier thermostats the reversing valve stays in cooling position until the thermostat goes to heat or off
Timings and thresholds
| Item | Value |
|---|---|
| Compressor time delay | 5 min |
Applies to: Carrier / Bryant / Payne split heat pumps with HK32EA defrost control boards (Performance Series and Comfort Series)
Models
More Carrier heat pump sequences
- Single-stage communicating heat pump: time delays and operating functions · Startup
- Variable-speed unit: power-up and compressor time delays · Startup
- Non-communicating heat pump: heating cycle (HK32EA001/007 and 003/008) · Heating
- Non-communicating heat pump: time/temperature defrost and Quiet Shift · Defrost
- Single-stage communicating heat pump: demand defrost, Auto interval and Quiet Shift-2 · Defrost
- Variable-speed heat pump: demand defrost with Auto interval · Defrost
- Single-stage communicating heat pump: pressure switch protection and lockout · Other
- Variable-speed unit: high pressure switch protection and lockout · Other
Related
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Source: Carrier-Bryant residential A/C + HP Application Guideline and Service Manual (R-410A, 24-25), System Function and Sequence of Operation, Defrost Control. Written in our own words; timings can differ by model and software version, so check the manual for your exact unit.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.