Fujitsu 9RLF, Service Instructions Manual

Page: 16 / 60

20. DEFROST OPERATION CONTROL
01-13
1. CONDITION OF STARTING THE DEFROST OPERATION
The defrost operation starts as shown in the following Table 16.
2. CONDITION OF THE DEFROST OPERATION COMPLETION
Release Condition
Outdoor heat exchanger temperature sensor value is higher than
+60.8°F (+16°C) or Compressor operation time has passed 15 minutes.
(Table 16 : Condition of starting Defrost Operation)
Defrost operation is released when the conditions become as shown in Table 17.
(Table 17 : Defrost Release Condition)
Integrating defrost
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.
Normal defrost
Compressor integrating operation time
Less than 25 minutes More than 25 minutes
Does not operate
Outdoor heat exchanger temp. < 1.4°F (-17°C)
(at outside air temp. > 14°F (-10°C))
Outdoor heat exchanger temp. < Outside air temp.- 12.6°F (7°C)
or Outdoor heat exchanger temp. < - 4°F (-20°C)
(at outside air temp. < 14°F (-10°C))
More than 240 minutes
(For continuous operation)
Less than 10 minutes
( For
intermittent operation )
Compressor integrating operation time
Outdoor heat exchanger temp.
below 26.6°F (-3°C)
OFF count of the compressor
40 times
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