20. DEFROST OPERATION CONTROL
2. CONDITION OF THE DEFROST OPERATION COMPLETION
Defrost operation is released when the conditions become as shown in Table 17 .
( Table 17 : Defrost release condition )
Release Condition
Outdoor heat exchanger temperature sensor value is higher than 15°C or
Compressor operation time has passed 15 minutes.
1. CONDITION OF STARTING THE DEFROST OPERATION
The defrost operation starts when the outdoor heat exchanger temperature sensor detects
the temperature lower than the values shown in Table 14, 15, 16.
1-1 NORMAL DEFROST
Integrating defrost
( OFF count defrost )
More than 210 minutes
( For continuous operation )
Compressor integrating operation time
(and after 30 minutes,
if the Tn < -3°C)
1-2. INTEGRATING DEFROST
( Table 15 : Condition of integrating defrost operation )
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.
Less than 10 minutes
( For intermittent operation )
Compressor integrating operation time
OFF count of the compressor 40 times
( at outside air temp. < 2°C )
1-3. INTEGRATING ( OFF COUNT ) DEFROST
( Table 16 : Condition of integrating ( OFF count ) defrost operation )
( Table 14 : Condition of starting defrost operation )
Normal defrost
Less than 35 minutes
Does not operate
Compressor integrating operation time
More than 35minutes
Tn < -17°C
(at Ta > -10°C)
Tn < 0.8
×
Ta - 11.6 or Tn < -24°C
(at -20°C < Ta < -10°C)
Tn - Tn-1 < -2°C and Sn = Sn-1
(Tn < -6°C )
(at Ta < -20°C)
=
=
=
Tn < 0.8
×
Ta - 11.6
=
=
=
or Tn < -28°C
=
=
Tn
Ta
Tn-1
Sn
Sn-1
: Outdoor heat exchanger temp.
: Outside air temp.
: Before 5 minutes detected Tn
: Number of operation indoor units
: Before 5 minutes detected Sn
Tn < -3°C
=
=
(and after 3 minutes,
if the Tn < -5°C)
Tn < -5°C
=
=
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