Mitsubishi Electric e Series Service Handbook page 152

[ IX Troubleshooting ]
Control Circuit
-6- Control Circuit
Troubleshooting transmission power circuit of unit
Check the voltage at the internal
transmission terminal block (TB3) of unit.
Check the voltage at TB3 after removing transmission line from TB3.
Check voltage of terminal block for centralized control (TB7).
Check voltage of TB7 by removing transmission line from TB7.
Check the voltage between No.1 and No.2 pins of the
CNS2 on the control board.
Check the voltage between No.1 and No.2 pins of the
CN102 on the power supply board for the transmission line.
Check the voltage between No.1 and No.3 pins of
the noise filter CN4.
Check the voltage between No.1 and No.3 pins of
the noise filter CN5.
Check the noise filter F4 fuse.
Check the voltages among TB22 and TB24 on the
noise filter.
Check the voltage between L2 and N at the power supply
terminal block TB1.
HWE1417B
DC 24 ~ 30 V
NO
DC 24 ~ 30 V
NO
DC24 ~ 30V
NO
DC24 ~ 30V
NO
DC24 ~ 30V
NO
DC24 ~ 30V
NO
DC279 ~ 374V
NO
DC279 ~ 374V
NO
F4 blown
NO
AC198 ~ 264V
NO
AC198 ~ 264V
NO
YES
Check whether the transmission line is disconnected,
check for contact failure, and repair the problem.
YES
Check if the internal transmission line is not
short-circuited, and repair the problem.
Check the wiring between the control board and power
YES
supply board for the transmission line (CN102 and CNIT),
and check for proper connection of connectors.
YES
NO
Is there a wiring
error or a connector
disconnection?
YES
YES
Replace the control board.
YES
YES
Is there a connector
disconnection?
NO
Check the voltage between No.5 and No.2 pins
of the CNIT on the control board.
YES
NO Is the voltage
measurement between
4.5 and 5.2 VDC?
YES
Replace the control board.
YES
Replace the M-NET board
YES Disconnect the noise filters CN4 and CN5, and then
replace F4, then turn the power on.
YES
F4 blown
NO
Connect the noise filter CN4, and then turn the power on.
YES
F4 blown
NO
Replace the M-NET board
YES
Replace the noise filter.
YES
Replace the noise filter.
Check and fix any power supply wiring and main power
supply problems found.
- 143 -
Fix the wiring and connector
disconnection.
Check for shorted transmission
line or power feed collision for
centralized control.
Fix the connector disconnection.
Replace the M-NET board
Replace the noise filter.
Replace the control board.
Turn on the
power again.
GB