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DEFROSTING OPERATION(FOR A UNIT HEAT EXCHANGER)
OPERATION DETAILS
-1.5˚C
Defrosting starts
Defrosting stop
Temperature of
outdoor heat exchanger
2min.
15˚C
Compressor
Outdoor fan
4way valve
ON
ON
ON
ON
OFF
50sec.
50sec.
Max 12min.
53sec.
53sec.
10
sec.
OFF
ON
MAX 90Hz
• Defrosting operation is controlled by the temperature of outdoor heat exchanger sensed by the thermistor and the
timer switch.
• Defrosting operation starts when the both of the following conditions are met at the same time.
a)40 minutes’(*1) of continuous run of the compressor after the start of heating operation or after the completion of
previous defrosting operation.
b)The temperature of the outdoor heat exchanger stays lower than -1.5°C(*2) continuously for two minutes.
• Defrosting operating is called off if either of the following conditions is met.
a)The temperature of outdoor heat exchanger rises to 15°C while 4-way-valve is ON.
b)12 minutes has passed since compressor turned ON.
• Working condition of frost protection heater for expansion vessel
The heater turns ON if the outdoor temperature keeps below 3 degree for 1 minute.
The heater turns OFF if the outdoor temperature keeps above 5 degree for 1 minute.
(*1) The period of time may be different in different cases.
(*2) This temperature may be different in different cases.