Fujitsu AOYG07KMTA, Service Manual

Page: 56 / 105

22. DEFROST OPERATION CONTROL
01-17
1. CONDITION OF STARTING THE DEFROST OPERATION
The defrost operation starts when the outdoor heat exchanger temperature sensor (Tn) detects
the temperature lower than the values shown in Table22.
2. CONDITION OF THE DEFROST OPERATION COMPLETION
Defrost operation is released when the conditions become as shown in Table 23.
( Table 23 : Defrost Release Condition )
Release Condition
Outdoor heat exchanger temperature sensor value is higher than +16°C.
or Compressor operation time has passed 15 minutes.
( Table 22 : Condition of starting Defrost Operation )
1 time defrosting
after starting operation
ST
Defrosting after 2
ND
time
upon starting operation
Compressor integrating operation time
Compressor integrating operation time
Compressor integrating operation time
Less than 22 min. 22 to 62 min. More than 62 min.
Does not operate - 9°C - 5°C
07-12KM: Less than 25 min.
14KM: Less than 40 min.
07-12KM: More than 25min.
14KM: More than 40min.
Integrating defrost
(Constant monitoring)
More than 240 min.
(For long continuous operation)
Less than 10min.*1
(For intermittent operation)
- 3°C
More than 215 min.
(For long continuous operation)
- 5°C
OFF count of the compressor
40 times.
*1 : If the compressor continuous operation time is less than 10 minutes,
the OFF number of the compressor is counted.
If any defrost operated, the compressor OFF count is cleared.
Tn10 : Temperature of continuous operation at 10minutes.
Tnb : Back 5minutes temperature
Does not operate
Outdoor heat exchanger temp. < -17°C
(at outside air temp. > -10°C)
(at outside air temp. < -10°C)
1 Outdoor heat exchanger temp.< -20°C
2 Outdoor heat exchanger temp.< Outside air temp.
3 Tn-Tn10< -5°C (and Tn< -6°C)
4 Tn-Tnb< -2°C (and Tn< -6°C)
=
=