Panasonic CS-E7GKEW Service Manual page 47

13.2.16 Compressor Operation Frequency
•
The compressor operation frequency is determined by room temperature, capacity, and model type.
a) When operation is started after the air conditioner has been stopped for more than one hour, the air
conditioner operates at a high frequency which lowers the room temperature quickly for cooling (or raises it
quickly for heating).
b) If two or more indoor units are operating simultaneously, the thermostat is set to OFF in one room; the
automatic expansion valve is closed to adjust the flow of refrigerant so as to control the room temperature.
c) When the thermostat is set to OFF during 1-room operation, the compressor and fan of the outdoor unit are
stopped. (The outdoor unit fan is stopped 30 seconds after the compressor stops).
d) It takes about 180 seconds to restart operation when the compressor has been stopped (Time delay safety
control)
13.2.17 Deice Operation
•
During Heating operation, the deice operation judgment method:
According to outdoor heat exchanger temperature, operation time and outdoor air temperature.
•
Deice operation
1. The outdoor heat exchanger temperature falls below 3°C continuously for 3 minutes
2. During deice operation; the 4-way valve is switched to cooling cycle to melt the frost.
3. Deice operation ends about 12 minutes of operation or the temperature of heat exchanger rises above 25°C.
Deice operation Characteristic
Elapsed time
Operating time
temperature of
heat exchanger
Fuzzy control makes it increasingly harder to initiate the deice operation as the outdoor
temperature drops.
Deice operation
Frequency
2-Room max.
1-Room max.
2-Room min.
1-Room min.
Conversion point
1-Room
low load
40 min. 40 min.
(outdoor air (outdoor air
temperature temperature
below -3°C) above -3°C)
-11°C -9°C
4-way valve
Cooling cycle
Cooling / Heating
2-Room
operation
1-Room
operation
Addition of capacity +
model to room temperature
1-Room
high load
2-Room operation
Deicing start
80 min. 120 min.
(outdoor air (outdoor air
temperature temperature
above -1°C) above -1°C)
-7°C
Outdoor unit fan
Stopped
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End
12 min.
-6°C 25°C
Indoor unit fan
Stopped