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Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
30
Defrost Control
The outdoor unit activates defrosting operation by T3 and accumulative heating time after the latest defrosting.
Table 32 —Defrosting Operation
*1 Outdoor fan will run at step level W2 to prevent abnormal increase in high pressure value. This protection is shown as below.
A210271
Table 33 —Stop Control
Component Before Defrosting Operation Defrosting Operation After Defrosting Operation
Compressor
Current value
→30 Hz for 10 seconds
30 Hz for 30 seconds → Target
frequency for defrosting operation
(58 Hz for 38VMB036HDS3-1,66 Hz for
38VMB048, 060HDS3-1)
→30 Hz for 55 seconds, then adjusts to
normal control
Outdoor unit fan Normal control
ON for ten seconds, then OFF
*1
OFF for 45 seconds, then normal control
Four way valve (ST1) ON ON for ten seconds, switch to OFF OFF for 45 seconds, then switch to ON
EEV Current opening → 480 Pls 480 Pls 300 Pls for four minutes, then normal control
Fast oil return (SV4) Normal control
Hot gas bypass valve (SV5) OFF OFF Bypass control
Spraying liquid valve (SV6) Discharge temperature protection control
Ending conditions -
Defrosting time reaches ten minutes
or T3 ≥ 54°F for one minute, or T3 ≥
68°F
six minutes
Component Cooling Operation Heating Operation
Compressor OFF
Outdoor unit fan W7 step level for 30 seconds, then OFF
Four way valve (ST1) OFF
Thermo-off standby: ON
Stop: ON for 15 seconds, then OFF
EEV 300 Pls
Fast oil return (SV4) ON for two minutes, then OFF
Hot gas bypass valve (SV5) OFF
Spraying liquid valve (SV6) OFF
Crankcase heater ON if T4 ≤ 37°F with compressor stopped for more than three hours, or powered on for the first time, else OFF
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