Mitsubishi Electric City Multi CMB-WP108V-G, Service Manual

Page: 159 / 301

[
IX
Troubleshooting ]
- 150 - HWE1113B GB
4220?4225
1. Error Code
Abnormal bus voltage drop (Detail code 108)
2. Error definition and error detection method
If Vdc 289V or less is detected during Inverter operation. (S/W detection)
3. Cause, check method and remedy
(1) Power supply environment
Check whether the unit makes an instantaneous stop when the detection result is abnormal or a power failure occurs.
Check whether the power voltage (Between L1 and L2, L2 and L3, and L1 and L3) is 342V or less across all phases.
(2) Voltage drop detected
4220
Œ
Check the voltage between the FT-P and FT-N terminals on the INV board while the inverter is stopped and if it is 420 V or
above, check the following items.
1) Confirm on the LED monitor that the bus voltage is above 289V.
Replace the INV board if it is below 289 V.
2) Check the voltage at CN72 on the control board. ->Go to (3).
3) Check the noise filter coil connections and for coil burnout.
4) Check the wiring connections between the following sections
Between the noise filter board and INV board. Between the INV board and DCL.
Replace 72C if no problems are found.
5) Check the IGBT module resistance on the INV board (Refer to the Trouble shooting for IGBT module). (page 225)
Œ
Check the voltage between the FT-P and FT-N terminals on the INV board while the inverter is stopped and if it is less than
420 V, check the following items.
1) Check the coil connections and for coil burnout on the noise filter.
2) Check the wiring between the noise filter board and INV board.
3) Check the connection to SCP1 and SC-P2 on the INV board.
4) Check the in-rush current resistor value.
5) Check the 72C resistance value.
6) Check the DCL resistance value.
Replace the INV board if no problems are found.
4225
Œ
Check the voltage at CNVDC on the Fan board while the inverter is stopped and if it is 420 V or above, check the following
items.
1) Check the voltage at CN72 on the control board. ->Go to 3).
2) Check the noise filter coil connections and for coil burnout.
3) Check the wiring connections between the following sections
Between the INV board and the Fan board.
4) Check contents 4220
Replace the Fan board if no problems are found.
Œ
Check the voltage at CNVDC on the Fan board while the inverter is stopped and if it is less than 420 V, check the following
items.
1) Check the state of the wiring connections between the INV board and the Fan board.
2) Check contents 4220
Replace the Fan board if no problems are found.
(3) Control board failure
Confirm that DC12V is applied to the connector CN72 on the control board while the inverter is operating. If not, replace the
control board.
Refer to section -7- "Inverter" under part [4] Troubleshooting Principal Parts for error codes related to the inverter.(page 220)
4220
4225