Fujitsu AMUG24LMAS, Service Manual

Page: 132 / 200

11. DEFROST OPERATION CONTROL
1. CONDITION OF STARTING DEFROST OPERATION
Condition
2. CONDITION OF THE DEFROST OPERATION COMPLETION
Defrost operation is released when conditions become as below.
Outdoor heat-exchanger temperature is higher than 59.0°F (15°C)
Outdoor heat-exchanger temperature is higher than 55.4°F (13°C)
AOU24/30RGLX
AOUG36/48LMAS1
or Compressor operation time has passed 15 minutes.
or Compressor operation time has passed 15 minutes.
Defrost operation starts as below.
AOU24, 30RGLX,
Condition
Less than
35 minutes
More than 35 minutes
Does not work
Compressor
integrating
operation time
AOU24/30RGLX
(1st defrost after starting operation)
Condition
Less than
17 minutes
More than 17 minutes More than 57 minutes
Does not work
Compressor
integrating
operation time
Integrating (OFF count) defrost operation
AOU24/30RGLX
(2nd defrost or later after staring operation)
Compressor
integrating
operation time
Tn
≤
-13°F (-25°C)
Tn - Tn10 < 9°F (-5°C) ( Tn
≤
21.2°F (-6°C))
Tn - Tnb < -3.6°F (-2°C) ( Tn
≤
21.2°F (-6°C))
Tn10 : Temperature of continuous operation at 10 minutes.
Tnb : Back 5 minutes temperature.
Tn : Outdoor heat-exchanger temperature.
Ta : Outside temperature.
More than 210 minutes
(For long continuous operation)
Condition
More than 210 minutes
( For long continuous operation )
(and after 30 minutes, if 26.6°F (-3°C)) (and after 5 minutes, if 23°F (-5°C))
(and after 5 minutes, if 23°F (-5°C))
Condition of Integrating defrost operation
Compressor
integrating
operation time
Less than 10 minutes
(For intermittent operation)
OFF count of compressor : 40 times
①
②
③
If 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.
(and after 5 minutes, if 41°F (5°C))
Ta - Tn
≥
41°F (5°C)
and
Tn
≤
15.8°F (-9°C)
Tn
≤
26.6°F (-3°C) Tn
≤
23°F (-5°C)
Tn
≤
23°F (-5°C)
04-25
Less than 35 minutes More than 35 minutes
Does not operate
Normal defrost
AOUG36/48LMAS1
Tn 1.4°F (-17°C)
(at Ta
°F
Tn - Tn-1
Compressor integrating operation time
<=
>= 14°F (-10°C)
Tn 0.8 x Ta-11.6 or Tn -18.4 (-28°C)
<= <=
(at 4°F (-20°C) <= Ta< 14°F (-10°C)
°F Tn 0.8 x Ta-11.6 or Tn -18.4 (-28°C)
<= <=
(at Ta < 4°F (-20°C))
< 28.4°F (-2°C)
(Tn 21.2°F (-6°C))
Tn-1 : Before 5 minutes detected Tn.
Tn : Outdoor heat-exchanger temperature.
Ta : Outside temperature.