Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 833

(ii) Compressor control
Retention
Reset
115°C
Discharge pipe temperature ( Tho-D1 )
(iii) Discharge pipe temperature error
• When the discharge pipe temperatures (Tho-D1, D2 detection) rise beyond 130˚C and is maintained for 2 seconds, the com-
pressors (CM1, CM2) are stopped but it will be reset if the temperatures drop below 90˚C.
• If the discharge pipe temperature (Tho-D1~D2 detection) occurs twice within 60 minutes or the condition higher than 130˚C has
continued for 60 minutes including the duration of time of compressor stop, the unit operation is stopped with the error stop.
Note (1) Unless the temperature of 90˚C or under is maintained for 45 minutes after the discharge pipe error, the unit cannot be started again. (Reset the
power supply to clear.)
(g) Current safe control
(i) If the incident current value (T phase of converter entrance) at the inverter entrance exceeds the setting value, the frequency
is reduced in the unit of 5 Hz so as to control the operation current.
(ii) If the required frequency becomes lower than the current safe frequency under this control, the latter frequency dominates
the operation.
(iii) If the frequency is maintained continuously below the reset value for 3 minutes, the operation enters the frequency release mode.
If it fails to reduce the frequency for 6 minutes continuously, this control is released and the operation returns to the normal mode.
(h) Current cut control
Current cut protects the inverter from overcurrent. If current exceeds the setting value, it stops the inverter immediately and resets
the inverter automatically 3 minutes later. After the automatic reset, the inverter starts at 35 Hz and raises the frequency by 5 Hz at
every 30-second till the frequency reaches the target value. If the current cut function is actuated four times within 15 minutes, it
turns OFF the 52C and stops the operation with the error stop.
(i) Power transistor overheat protection.
If the power transistor is heated up to the setting temperature (118˚C), the inverter is stopped immediately but reset automatically
3 minutes later or if the temperature drops to the normal level
If the control is actuated again within 2 hours or has continued for one hour, the inverter is stopped with the error stop.
(j) Expansion valve control for oil return
When the compressor is started initially after turning power ON or accumulated time of compressor ON exceeds 10 hours, this
control stops the compressor, turns the thermostat and blowing OFF and fully opens expansion valves, one by one at intervals of 4
minutes, of the unit stopped with the error stop, in order to collect lubrication oil.
Notes (1) Expansion valves are opened fully in the order of registration of addresses on the outdoor unit not in the order of address No.
(2) Expansion valves are opened for 1 minute on the unit in the cooling or dehumidifying mode or 4 minutes on the unit in the heating mode.
(k) Abnormal high pressure rise protection
If either one of high pressure switches [63H1-1, 63H1-2, FDCJ: 2.94 open/2.35 close MPa (30 open/24 close kgf/cm
3.24 open/2.65 close MPa (33 open/27 close kgf/cm
stop.
[However, when the switch is actuated initially, the compressor stops for a delay of 3 minutes and then returns to the normal
operation.]
Compressor capacity is reduced.
Compressor capacity is reduced at every minute.
120°C
Retention
CM operation
90°C 130°C
Discharge pipe temperature (Tho-D1~D2)
2
)] is actuated twice within 40 minutes, the compressor stops with the error
CM stop
FDC-HKX
2
) , FDCP:
831