Toyotomi TAN-A70IV Service Manual page 11

DEFROSTING OPERATION(FOR OUTDOOR UNIT HEAT EXCHANGER)
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' 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 -2°C 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 12°C while 4-way-valve is ON.
b) 12 minutes has passed since compressor turned OFF.
Temperature of
outdoor heat exchanger
-2˚C
Compressor
Outdoor fan
4way valve
Defrosting starts
12˚C
2min.
ON OFF
ON
10
sec.
50sec.
53sec.
– 10 –
OPERATION DETAILS
2min. 2min.
50Hz 68Hz 85Hz
ON
Max 12min.
Defrosting stop
OFF ON
ON
50sec.
53sec.