Toyotomi TAN-A28FWIS Service Manual page 13

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 8°C while 4-way-valve is ON.
b) 12 minutes has passed since compressor turned ON.
Temperature of
outdoor heat exchanger
-2˚C
Compressor
Outdoor fan
4way valve
Defrosting starts
8˚C
2min.
3min.
ON OFF
ON
10
sec.
50sec.
53sec.
TAN/ TAG-A28FWIS
TAN/ TAG-A32FWIS
– 12 –
OPERATION DETAILS
2min.
2min.
MAX
50Hz 67Hz
★
ON
Max 12min.
★
60Hz
80Hz
Defrosting stop
OFF ON
ON
50sec.
53sec.