Mitsubishi Electric PU(H)Y-P250YGM-A Service Handbook page 130

Error definition and error
Error Code
4220 Bus voltage If Vdc 289V or less is de-
4225 drop tected during Inverter op-
(Detail code eration. (S/W detection)
108)
If Vdc 817V or more is
Bus voltage rise
(Detail code 109)
detected during inverter
operation.
Abnormal VDC Bus voltage abnormality If Vdc
(Detail code 110) 772V or more or Vdc 308V or
less is detected. (H/W detec-
tion)
detection method
(1) Power supply environment
(2) Voltage drop detected
(3) Main board failure
(4) 52C failure
(5) Diode stack failure
(1) Different voltage connection
(2) INV board failure
Same as detail code No.108
and 109 of 4220 error
- 121 -
Cause 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
-> Check the followings when
1) Check the voltage of CN52C on
the main board.
Refer to (3).
2) Check whether 52C works normally
Refer to (4).
Or check 52C connecting piping.
3) Check for the diode stack.
Refer to (5).
4) Check for the wiring and the con-
nectors between the CNDC2 on
the compressor 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 following.
1) Check the voltage of CN52C on the
main board.
Refer to (3).
2) Check whether 52C works normally
Refer to (4).
Or check 52C wire connection.
3) Check for 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 AC220~240V is applied to
the male connector (CN52C) on the main
board during inverter operation.
->If not applied, check the main board
Refer to 9 [4]-6-(4) and check the
coil resistance check.
Refer to 9 [4]-6-(6) and check the di-
ode stack resistance.
Check the power supply voltage on the pow-
er 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.
[ IX Troubleshooting ]
there is no voltage drop.
there is a voltage drop.
and the fuse (F01 andF02).
Replace the main board when no
fault is found.