Mitsubishi P120 Air Conditioner User Manual


 
[ IX Troubleshooting ]
- 273 -
HWE09120 GB
(2) Troubleshooting transmission power circuit of outdoor unit
1) PUHY-P72, P96, P120, P144YJMU-A
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
DC270
~
356V
AC41
4
~
506V
Fuse
F4 on the noise filter board is blown.
AC414
~
506V
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
YES
NO
YES
YES
NO
NO
NO
YES
YES
YES
NO
NO
NO
YES
NO
YES
Check the voltage between L2 and L3 at the power supply
terminal block TB1.
Check the voltages among TB22 and TB23 on the
noise filter
Fuse
F5 is blown.
Fuse F5 is blown.
Fuse F5 is blown.
Check
fuse
F5.
Pull out CN4 and CN5 on the noise filter, replace fuse F5, and turn on the power.
YES
Check the voltage at the indoor/outdoor
transmission terminal block (TB3) of outdoor unit.
DC 24 ~ 30 V
Check the voltage at TB3 after removing transmission line from TB3.
DC 24 ~ 30 V
DC 24 ~ 30 V
DC 24 ~ 30 V
DC 24 ~ 30 V
DC 24 ~ 30 V
Check whether the male connector is connected to
the female power supply connector (CN40).
Connected
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.3 pins of
the noise filter CN4.
DC270
~
356V
Check the voltage between No.1 and No.3 pins of
the noise filter CN5.
Check the noise filter fuse F4 .
Turn on the
power again.
Check and fix any power supply wiring and main power supply problems found.
Replace the noise filter.
Replace the noise filter.
Replace the M-NET board
Connect the noise filter CN4, and then turn the power on.
Replace the control board.
Replace the noise filter.
Replace the noise filter.
Replace the control board.
Fuse F4 on the
noise filter board is blown.
Fuse F4 on the
noise filter board is blown.
Disconnect the noise filters CN4 and CN5, and then replace fuse F4 on the noise filter
board, then turn the power on.
Connect the noise filter CN4, and then turn the power on.
Replace the M-NET board
Replace the M-NET board
Replace the control board.
Is the voltage
measurement between
4.5 and 5.2 VDC?
Replace the M-NET board
Check the voltage between No.5 and No.2 pins of the CNIT
on the control board.
Is there a connector
disconnection?
Fix the connector disconnection.
Check whether the transmission line is disconnected,
check for contact failure, and repair the problem.
Check if the indoor/outdoor transmission line is not
short-circuited, and repair the problem.
Check the wiring between the control board and power supply board for the
transmission line (CN102 and CNIT), and check for proper connection of connectors.
Check the wiring between the control board and power supply board for the
transmission line (CN102 and CNIT), and check for proper connection of connectors.
Fix the wiring and connector disconnection.
Check for shorted transmission line or power feed
collision for centralized control.
Replace the control board.
Is there a wiring
error or a connector
disconnection?
Check the voltage between No.1 and No.2 pins of the
CN102 on the power supply board for the transmission line.
[YJMU-A]