15
Overload
prevention works.
Does outdoor fan
stop?
6) DEFROSTING OPERATION (HEAT PUMP MODEL)
●
When the capacity of unit bas been decreased due to frost sticking to the outdoor heat exchanger during heating,
the temperature drop gradient is detected by the microcomputer controlled temperature sensing system, and
defrosting operation is started. At this time, the indoor and outdoor fan motors wills stop, only the compressor is
operated, and the system is automatically changed to cooiling operation mode.
DEFROSTING FLOWCHART
Heating operation
Integrated operating time of com-
pressor is more than 3 hours
Cold-draft
prevention
Indoor fan runs at set speed when
temperature od indoor heat exchanger
reads 34°C
Release of defrosting
Continuos operating time of com-
pressor is more than 20 minutes
Compressor keeps running for at
least 6 minutes
Outdoor fan is either operated or
stopped for more than 10 minutes
Is outdoor fan continuolsy opera-
ting for more than 10 minutes?
Integrate operating time of com-
pressor is more than 50 minutes
Temperature of indoor heat
exchanger coil is below 54 °C
Compressor keeps running for at
least 6 minutes
Compressor keeps running for at
least 6 minutes
Temperature of outdoor heat exchanger
coil is below 9 °C
Defrosting time is over
12 minutes
Temperature of outdoor heat
exchange coil is higher than 12 °C
Integrated operating time of com-
pressor is more than 1,5 hours
Indoor heat exchanger coil tem-
perature drops 0,8 °C for 6
minutes and it repeats 3 times in
succession
Thermo. (OFF)
(Compressor OFF)
Temp. of indoor heat exchanger
coil is below 41 °C
Temperature of indoor heat
exchanger coil immediately
before thermo goes off is either
below 45 °C or 58 °C (when
overload prevention works)
Compressor ON
Defrosting begins
A
NO
NO
NO YES
SI
YES
B C D
Release of overload prevention
(Outdoor fan operates)
