Panasonic U-72MF2U9 Service Manual page 42

9. Defrost Control
9. Defrost Control
* 1 Reverse cycle defrost process
This reverse cycle defrost process is performed after outdoor units, indoor units and solenoid valve kits are
changed to the cooling cycle.
All Indoor Units
1
Heating
2
Evaporator
3
Evaporator
4
5
6
7
8
9
Control time
Outdoor units
Expansion valve
Solenoid valve kit
Fan
Stop
Defrost
Stop
(DEF)
Stop Stop
Minimum 1 minute – Maximum 15 minutes
(Until all outdoor units' heat exchanger temperature ≥ 59°F (15°C))
Outdoor unit operates at maximum horsepower.
Valves at all indoor units operate at a fixed pulse according to the
indoor unit capacity.
Valve kits at all indoor units operate in cooling mode (ON status).
Stop and cooling operation of indoor units will be followed by the
indoor unit control system.
Fan and heating operation of indoor units are changed to stop.
Defrost
Defrost
Stop
(DEF)
Defrost Defrost
(DEF) (DEF)
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3WAY SYSTEM
3WAY VRF SYSTEM
Control Functions
Control Functions
Stop Heating
Stop Evaporator
Stop Evaporator