Specifications
-
50
-
-20
-20
-15
-10
-5
-15 -10 -5
Outdoor air temperature (°C) [Th
0
-A]
Heat exchanger temperature
(°C)
[Th
0
-R]
0510
Zone for initiate temp. of defrost
Initiation tem
p. of defrosting
Note (1) If DIP switch SW5-1 on the printed circuit board for the outdoor unit is set to on, defrost operation will begin when temperature of
the heat exchanger for the outdoor unit reaches -7 °C.
a) Defrost finished
(i) Once defrost operation has started, it will finish after the cumulative operating time of the compressor has
reached 12 minutes (factory setting: SW5-1 OFF).
Note (1) This time will become 14 minutes if the DIP switch (SW5-1) on the printed circuit board on the outdoor unit is set to on.
(ii) Patterns of defrost control can be changed by changing the setting of J18 on the PCB of outdoor unit.
● J18 (SW6-2) with: Normal defrost control
● J18 (SW6-2) none: Forced defrost control
3) Defrost control (Only heat pump type)
Defrost operation will start when the temperature of the heat exchanger for the outdoor unit (Tho-R detection) and the
outdoor air temperature (Tho-A detection) enter the start of defrost range shown in the figure below.
Initiation temp. of defrosting (Detected by Tho-R, Tho-A)
4) Compressor protecting function (Microcomputer and phase protection relay)
a) Overcurrent control
(i) When a 52C secondary L
1-phase continues for 0.5 seconds and when it is more than the set value (detection
at current sensor CT), the compressor is stopped. The compressor is restarted after a 3-minute delay if the
detection current is less than 1.5 to 2A. If this condition is re-detected 5 times within 60 minutes of the first
occurrence, an abnormal stop of the unit is performed.
(ii) If 60 minutes passes and the detected current after the first to the fourth stoppage is not less than 1.5~2A, an
abnormal stop of the unit is performed.
b) Open-phase protection
When a 52C secondary detection current continues for 4 seconds when the compressor is on and when it is less
than 1.5 to 2 A, it is determined to be a open-phase of the 52C secondary N-phase, and the compressor is stopped.
The compressor is restarted after a 3-minute delay and if this condition is re-detected within 60 minutes of the first
occurrence, an abnormal stop of the unit is performed.
c) Cooling overload protection
State of overload during cooling operation is detected (with Tho-R) based on the temperature of outdoor heat
exchanger and the unit operation is stopped / Immediate reset after repair
60
Outdoor heat exchanger temp. (°C)
70
Error stop
Operable
d) Thermistor (Heat exchanger and outdoor air thermistor) disconnected wire
(i) If there is a disconnected wire or if there is a big difference in performance characteristics, an abnormal stop
of the unit is performed. e Restore after repairing.