Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 77

(10) Forced defrosting (Heat pump type only)
To test forced defrosting in the operation test mode, the unit may be operated once in the forced defrost mode as shown below.
S32, 40 models
Temporarily turn off the power source and then perform the following operation using the remote controller within 20 seconds
after the power is turned back on.
: Run
Operation
: Low
Fan speed
Operation setting : Heating
Temperature setting : 19
S50, 56 models
Turn the unit off and then on again, then perform the following operations within 20 seconds. ON-OFF: "ON"; FAN SPEED:
"LO"; Operation mode switch: "HEAT": Room temperature adjustment: "19", Timer switch: "ON"; Airflow switch: Swing,
Time: as desired; Start time: 180 minutes after present time: (Refer to note (1))
Note (1) Example of timer setting.
Clock:
ON time:
¡When the remote control operation is performed, forced defrosting will start for one minute after the three minute timer
operation ends. After that the defrost thermostat(23DH) will either turn OFF or the operation will stop after 10 minutes.
(11) High-pressure control (Heat pump type only)
The indoor heat exchanger thermistor detection temperature controls the indoor fan and compressor.
¡ When the indoor heat exchanger
temperature Is
Indoor fan
Set fan
Speed
Indoor heat exchanger temperature (˚C)
(12) Three-minute forced operation
When the compressor begins operating the thermal operation is not effective for three minutes, so operation continues as is in the
operation mode. (After three minutes has passed the thermal operation is effective.)
However, stopping the compressor via a stop signal or protection control has priority.
(13) Heating operation overload protection (Heat pump type only)
During heating operation in overload condition (room outside air temperature is considerably high), in order to protect the unit, the
outdoor fan is controlled by the pressure switch (63H) and the compressor and outdoor fan are controlled by the heat exchanger
sensor (Th )
2
(a) Outdoor fan control
High pressures are prevented and extreme heat
absorption controlled by turning the outdoor fan ON
and OFF with the pressure switch.
Outdoor fan
32,40: 2.02(20.5)
50,56: 1.86(19.0)
High pressure MPa (kgf/cm
Air flow
Timer switch : On timer (
On time
AM 4:00
AM 7:00
61˚C
Speed 4
50 61
ON
OFF
2.41(24.5)
2 )
: Swing
)
: 3H
¡ When the indoor heat exchanger
temperature Is 64˚C
ON
Compressor
50
Indoor heat exchanger temperature (˚C)
(b) Compressor and outdoor fan control
When high pressure occurs even with the outdoor
fan off, stop the compressor and outdoor fan with
the indoor heat exchange sensor to protect the unit.
Compressor
Outdoor fan
Indoor heat exchanger temperature (°C)
SRK-H
OFF
64
ON
OFF
50 64
75