Panasonic CS-A73KR Service Manual page 26

- If the compressor is operating continuously for 5 minutes or longer
and temperature difference between intake air and indoor heat
exchanger is 5°C or less for 2 minutes, compressor will stop and
restart automatically.
(Time Delay Safety Control is valid).
T = Indoor heat exchanger temperature - intake air temperature. /
This is to protect reverse rotation of the compressor when there is
a instantaneous power failure.
4-way Valve Control
- 4-way valve always ON during Heating operation. (Except Deicing
operation)
- When the unit is switched to "OFF" during Heating operation, 4-
way valve stay at Heating position for 5 minutes.
Outdoor Fan Motor Control
26