Troubleshooting - Mitsubishi TNW4EA Series Operation Manual

6 Troubleshooting

(1) Identifying the detail of trouble with the cabin controller
When the alarm symbol " " has turned on (the backlight blinks) or blinked at the monitor
display area, check the detail of trouble on the refrigeration unit.
Displaying the active alarm display
1
When the alarm symbol "
blinks) or blinked at the monitor display area, press the
[MODE] switch (twice if the refrigeration unit is stopped, or
once if the unit is operating) to change the screen to the
active alarm display. The alarm code displays at the bottom
of the digital display area, with up to 10 codes being
displayed sequentially at 2-second intervals. If there are no
active alarms, "
Press the [SET] switch to display the setting temperature / room temperature (when refrigeration
2
unit is running), or the clock (when refrigeration is unit is stopped).
List of alarm codes (If the alarm display
Alarm
Code
Evaporator fan motor fuse is blown.
Sub-engine run solenoid fuse is
blown.
Output relay fuse is blown.
Commercial power supply is faulty.
High-pressure switch is operating.
* 1
Low-pressure switch is operating.
Defrost solenoid valve is faulty.
" has turned on (the backlight
" displays.
Error Contents
lights up continuously)
Measures
Two or more of the fuses for the evaporator fan motor
have blown.
Inspect and replace the fuses F2 to F4 (TNW4EA: F2 to
F3) in the control box.
The run solenoid fuse for the sub-engine has blown.
Inspect and replace the fuses F5 in the control box.
The output relay fuse has blown.
Inspect and replace the fuse F7 in the control box.
The commercial power supply has failed, or the power
supply is disconnected.
Check the power supply. When carrying out operation
with the sub-engine, close the power supply plug cover.
The high-pressure switch has functioned.
Check whether the condenser coils are dirty, and clean
them if they are. Check the condenser fan or belt for
breakage. If any abnormality is found, contact your dealer.
The low-pressure switch at the high-pressure side has functioned.
Contact your dealer or nearest service shop.
The defrost solenoid valve operation is faulty.
Contact your dealer.
ADVICE If loading or unloading work is carried out while
the refrigeration unit is running, the alarm "
will display, and the refrigeration unit may stop
with a fault. In this case, the defrost solenoid valve
is not faulty. Press the "STOP" switch, and then turn the
RUN/STOP switch "RUN" again to resume operation.
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Alarm symbol display
Active alarm display
"
Refrigeration
Unit State
Refrigeration unit
operation stops.
Refrigeration unit
operation stops.
Refrigeration unit
operation stops.
Refrigeration unit
operation stops.
Refrigeration unit
operation stops.
(Auto recovery)
Refrigeration unit
operation stops.
Refrigeration unit
operation stops.