HVACopediaKeepRite · Heat pump · Cooling
Heat pump: cooling cycle
What happens, in order
- Power to indoor and outdoor units energizes the transformer
- On a call for cooling the thermostat makes R-O, R-Y and R-G
- R-O energizes the reversing valve into cooling position
- R-Y energizes the contactor, starting outdoor fan and compressor
- R-G energizes the indoor blower relay, starting the blower on high speed
- Thermostat satisfied contactor and blower relay drop out and compressor and motors stop; a time-delay relay in the indoor unit keeps the blower going 90 s more
Timings and thresholds
| Item | Value |
|---|---|
| Indoor blower run-on (with TDR) | 90 s |
Applies to: KeepRite / ICP N4H4, R4H4, WCH4, NXH5 heat pumps
Models
More KeepRite heat pump sequences
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Source: KeepRite/ICP N4H4-R4H4-WCH4-NXH5 heat pump installation instructions 428 01 5107 10, Defrost and Sequence of Operation. 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.