Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 287

[ IX Troubleshooting ]
Error Code
4220 Bus voltage
4225 drop
(Detail code
108)
Bus voltage
rise
(Detail code
109)
Abnormal VDC
(Detail code
110)
Refer to section -8- "Inverter " under part [4] "Trouble shooting principal parts" for error codes related to the inverter.
Error definition and error
detection method
If Vdc 150V or less is de- (1) Power supply environment
tected during Inverter op-
eration. (S/W detection)
(2) Voltage drop detected
(3) Main board failure
(4) 52C1 failure
(5) Diode stack failure
If Vdc 425V or more is (1) Different voltage connec-
detected during inverter
operation.
(2) INV board failure
Bus voltage abnormality If Same as detail code No.108
Vdc 400V or more or Vdc and 109 of 4220 error.
160V or less is detected.
(H/W detection)
Cause
tion
- 278 -
Check method and remedy
Check whether the unit makes an instanta-
neous stop when the detection result is ab-
normal or a power failure occurs.
Check whether the power voltage is 150V or
less across all phases.
In the case of 4220
Measure voltages of the male
connector (CNDC2) on the
compressor INV board.
-> Replace the INV board when
there is no voltage drop.
-> Check the followings when
there is a voltage drop.
1) Check the voltage of CN52C on the
main board.
Refer to (3).
2) Check whether 52C1 works nor-
mally.
Refer to (4) or check 52C1 con-
necting piping.
3) Check for the diode stack.
Refer to (5).
4) Check the wiring and the connectors
between the CNDC2-G on the com-
pressor INV board and the CNDC1 on
the G/A board.
Replace G/A board when no fault is
found for the above 1) - 4).
In the case of 4225
Check the followings.
1) Check the voltage of CN52C1 on the
main board.
Refer to (3).
2) Check whether 52C1 works normally.
Refer to (4).
Or check 52C1 wire connection.
3) Check diode stack failure.
Refer to (5).
4) Check the wiring and the connectors of
the CNVDC on the FAN INV board.
Replace FAN INV board when no fault
is found for the above 1) - 4).
Check whether AC208 / 230 V is ap-
plied to the male connector (CN52C1)
on the main board during inverter oper-
ation.
-> If not applied, check the main board
and the fuse (F01 andF02). Re-
place the main board when no fault
is found.
Refer to 9.[4].8.(4) and check the coil
resistance check.
Refer to 9.[4].8.(6) and check the di-
ode stack resistance.
Check the power supply voltage on the
power supply terminal block (TB1).
Replace the INV board when no fault is
found.
In the case of 4220: Compressor INV board
In the case of 4225: FAN INV board
Same as detail code No.108 and
109 of 4220 error.