Mitsubishi Heavy Industries FDT28KXE6A Service Manual page 24

(iv) If any anomaly occurs when the auto backup is effective, the operation output (CnH), Anomaly output (CnY), 7-seg-
ment display and LED show as follows.
1) At the system stop
Operation output on the master unit is turned OFF, the Anomaly output is turned ON, 7-segment display and
LED show the anomaly, and the remote controller displays E??. (To reset the anomaly, it is necessary to reset the
inspection from the remote controller.)
2) At the unit stop
On the unit only, the operation output is turned OFF, the Anomaly output is turned ON, 7-segment display and LED show
the anomaly and normal units continue their operation (stop).
To reset the state of anomaly on the unit the anomaly occurred, it depends on the condition to reset the state of each anomaly.
3) At the compressor stop
Only the compressor concerned stops, previous states are maintained on the operation output, anomaly output,
7-segment display and LED. To reset the state of anomaly on the compressor, it depends on the condition to reset
the state of each anomaly.
Remote controller
Anomaly contents
error display
Duplicated outdoor unit address No.
E31
Open L3 Phase on power supply at primary side
E32
Discharge pipe temperature anomaliy
E36
Outdoor heat exchanger and subcooling
E37
coil temperature thermistor anomaly
Outdoor air temperature thermistor anomaly
E38
Discharge pipe temperature thermistor anomaly
E39
High pressure anomaly
E40
Power thansistor overheat
E41
E42 Current cut
Excessive number of indoor unit connected,
E43
excessive to tal capacity of connection
Communication error between inverter
E45
PCB and outdoor control PCB
E48 Outdoor DC fan motor anomaly
E49 Low pressure error
E51 Power transister overheat (continuousness)
E53 Suction pipe temperature thermistor anomaly
High pressure sensor/Low pressure
E54
sensor anomaly
E55 Under-dome temperature thermistor anomaly
E56
Power transitor temperture thermistor anomaly
E59
Compressor startup failure
E60
Rotor position detection failure
Communications error between the master
E61
unit and slave units
E63 Emergency stop
(c) Prohibiting conditions of auto backup operation
(i) When the conditions of oil return control are not established
(ii) When the backup operation time has exceeded the limit value
(d) Control after the conditions to prohibit the auto backup operation have been established
All compressor stop, and the error display [E-XX] is shown on the 7-segment display and the remote controller.
In this state, the inspection reset of remote controller is effective. → [E-XX] is displayed continuously on the remote con-
troller.
Backup operation function is only for emergency purpose when one of compressors or one of units is damaged.
If backup operation is performed continuously for long period, it may cause the damage of good compressors.
Accordingly be sure to repair the damaged unit or to replace the damaged compressor and to cancel the
backup operation within 48 hours after starting backup operation.
Anomalous stop of master outdoor unit
System stop Unit stop Compressor stop System stop
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22
Anomalous stop of slave outdoor unit
Unit stop Compressor stop
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