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8. FUNCTIONS
8-1. Defrost Detection and End
8-1-1. Non-stop defrosting
Defrost sequence
4-way valve ON
Defrost detection occurs in either of the following cases:
• The temperature of the heat exchanger remains at or below
the L1 line for 35 minutes after the start of HEAT operation.
• The temperature of the heat exchanger remains at or below
the L2 line for 120 minutes after the start of HEAT operation.
End temperature
Defrost operation time
Coil temperature for
ending defrost
Less than 2 minutes
Not ended
2 minutes or more
*
1 10
°
C or higher
*
1 The temperature for ending defrost is 7
°
C or higher when the outdoor air
temperature is less than 0
°
C.
• Compressor
→
100 Hz operation (4-way valve ON)
• Outdoor fan
→
OFF
• Solenoid valve
→
ON
(for hot gas bypass)
• Indoor fan
→
OFF
• Temperature of the outdoor heat exchanger is at or above the
temperature shown in the table below.
• Defrost operation has continued for 12 minutes (max. length).
HEAT operation
Frost detection
Defrost end
Non-stop defrost operation
Outdoor heat
exchanger temperature
–13
0
– 8
– 9
–15
– 21
L1
L2
Outdoor air
temperature
NOTE: • Defrost does not occur during HIGH POWER operation.
If other stopped indoor units are started during defrost operation, they begin operating in
defrost
mode.
8-1-2. Clean defrost
If all indoor units are stopped during HEAT operation, and frost is detected at the L2 line, and the
conditions for defrost are met, then defrost operation occurs, and the unit stops after defrost is completed.
