6. Defrost operation control
Tn: Outdoor unit heat exchanger temperature
Ta: Outdoor temperature
Tn10: Temperature at 10 minutes after compressor start
Tnb: Temperature before 5 minutes
• Triggering condition
The defrost operation starts when outdoor unit heat exchanger temperature sensor detects the
temperature lower than the values shown below.
– 1st time defrosting after starting operation
Compressor integrating
operation time
Less than 17 min. 17 to 57 min. More than 57 min.
Condition Does not operate
Tn ≤ -9°C and Tn-Ta ≥ 5
deg
Tn ≤ -5°C
– 2nd time and after
• Models: AOYG18KBTB, AOYG22KBTB, and AOYG24KBTB
Compressor integrating
operation time
Less than 40 min. More than 40 min.
Condition Does not operate
Tn-Tn10 < -5 deg (Tn ≤ -6°C)
Tn-Tnb < -2 deg (Tn ≤ -6°C)
Tn ≤ -20°C (Ta ≥ -10°C)
Tn ≤ Ta-7°C or Tn ≤ -25°C (Ta <
-10°C)
• Models: AOYG30KBTB, AOYG36KBTB, and AOYG45KBTB
Compressor integrating
operation time
Less than 35 min. More than 35 min.
Condition Does not operate
Tn-Tn10 < -5 deg (Tn ≤ -10°C)
Tn-Tnb < -2 deg (Tn ≤ -10°C)
Tn ≤ -25°C (Ta ≥ -20°C)
Tn < Ta-7°C or Tn ≤ -25°C (Ta <
-20°C)
– Integrating defrost (Constant monitoring)
Compressor
integrating
operation time
18/22/24 model
More than 240 min.
(For long
continuous
operation)
More than 213 min.
(For long
continuous
operation
Less than 10 min.*
(For intermittent
operation)
30/36/45 model
More than 240 min.
(For long
continuous
operation)
More than 215 min.
(For long
continuous
operation
Less than 10 min.*
(For intermittent
operation)
Condition Tn ≤ -3°C Tn ≤ -5°C
Count of the
compressor off: 40
times
*: If the compressor continuous operation time is less than 10 minutes, the number of the com-
pressor off is counted. If any defrost operated, the compressor off count is cleared.
- (04-29) -
6. Defrost operation control
CONTROL AND
FUNCTIONS
CONTROL AND
FUNCTIONS