Protective Functions - Panasonic CU-5E34NBE-C Installationsanleitungen

7-2. Protective Functions

7-2-1. Defrost Detection and Release
(1) Non-stop defrosting
Defrost does not occur during HIGH POWER operation.
NOTE
If other stopped indoor units are started during defrost operation, they begin operating in
defrost mode.
(2) Clean defrost
If all indoor units are stopped during HEAT operation, and frost is detected at the L1 line, and the
conditions for defrost are met, then defrost operation occurs, and the unit stops after defrost is completed.
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Defrosting sequence
Heating operation
Frost detection
Non-stop defrosting
Releasing of defrosting
manuals search engine
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.
• Accumulated 2 hours have passed with the coil temperature
of -2 or less.
°C
Outdoor heat
exchanger temperature
(–20)
L2
L1
• Compressor (70 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).
Temperature of releasing
Defrost operation time Less than 2 minutes
Heat exchanger
No releasing
temperature for
releasing defrosting
*1 The temperature for releasing of defrosting is (20 °C) or higher when the
outdoor air temperature is less than 0 °C.
21
0
Outdoor air
temperature
(– 6)
(– 7)
(– 16)
(– 25)
2 minutes or more
14 °C or higher (*1)