Mitsubishi Heavy Industries FDT71VNXVD Service Manual page 90

Error code
Indoor control PCB
Remote controller:
E59
Outdoor control PCB
Outdoor
inverter
1. Applicable model
All models
2. Error detection method
If it fails to change over to
the rotor detection operation
of compressor motor (If the
compressor speed cannot
increase 11Hz or higher)
3. Condition of Error displayed
If compressor fails to startup for
20 times (10 patterns x 2 times).
(It is availabel to reset by
remote controller after 3
minutes delay)
4. Presumable cause
• Faulty outdoor fan motor
• Faulty inverter PCB
• Anomalous power supply
voltage
• Improper refrigerant amount
and refrigerant circuit
• Faulty compressor (Motor
bearing)
Note: Insulation resistance
• The unit is left for long period without power supply or soon after installation, migrated liquid refrigerant may dissolve in the refrigerant oil in the compressor.
In such case insulation resistance decreases upto several MΩ or lower. If the electric leakage breaker is activated due to low insulation resistance,
check followings.
Check whehter the insulation resistance can recover or not, ater 6 hours has passed since power ON.
(By energize the crankcase heater, migrated liquid refrigerant in the refrigerant oil in compressor can be evaporated)
Check whether the electric leakage breake conforms to high-hermonic specifications
(As units has inverter, in order to prevent from improper operation, be sure to use high-hermonic one.)
LED Green
Keeps flashing
Keeps flashing
Yellow LED
Stays off or 4 times flash
PCB
5. Troubleshooting
Compressor does not start at all.
Neither noise nor vibration cannot be heard
Does
compressor
startup?
NO
Is power
supply voltage
OK?
YES
the pressure balance
at starting OK?
YES
Is the
insulation resistance
and coil resistance of
compressor OK ?
YES
Is power transistor
module OK?
YES
After power OFF, turn JSW10-4 on
the inverter PCB ON and connect
the inverter checker. And then power
ON again.
(Regarding the checking method of
inverter PCB with inverter checker,
refer to page 50 in detail)
the output of inverter
checker OK ?
YES
Try to startup
several times
Does it start?
–
Red
Content
Stays OFF
Compressor startup failure
1 time flash
Diagnosis
Disconnect the outdoor fan motor
connector and try to startup
YES
NO
Is
NO
NO
NO (Inverter PCB is defective)
Is
NO
Note: Several times restarting
may resolve it, because migrated
liquid refrigerant in the
compresser is discharged from
the compressor.
NO
100
90
–
'10 • PAC-SM-137A
Countermeasure
Replace outdoor fan motor
Check power supply
voltage
Check refrigerant amount
and refrigerant circuit
Repalce compressor
Defective inverter PCB
Replace.
Defective inverter PCB
Replace.
Repalce compressor
*