Mitsubishi Heavy Industries FDTCVA SERIES Technical Manual page 251

Models 302~1002
±
The " WAIT " display remains the same
in the remote controller's LCD ever 2 minutes
has passed since the power supply was turned
ON.
YES
NO
Is the LED on the outdoor
unit's control PCB flashing?
YES
NO
Is the the indoor green
LED flashing?
YES
NO
Is the outdoor unit control PCB
red LED flashing 2 times?
YES
NO
Are the wires connecting the indoor
and outdoor units connected
according to specifications?
YES
Measure the voltage between
DC approx. 0V
terminals and of the outdoor
unit's terminal block.
DC approx. 20V
Measure the voltage between
DC approx. 0V
terminals 2/N and of the indoor
unit's terminal block.
DC approx. 20V
Indoor unit control
PCB is defect.
Remote controller does not display
after the power is turned on.
YES
Is the indoor green LED
flashing?
YES
Is the outdoor red LED
flashing 2 times?
YES
Are the wires connecting the indoor
and outdoor units connected according
to specifications?
YES
Measure the voltage between
terminals and of the
outdoor unit's terminal block.
Approx. 20V DC
Measure the voltage between
terminals 2/N and of the
indoor unit's terminal block.
Approx. 20V DC
Indoor unit
control PCB
defect
Indoor unit
Is the inverter PCB LED
control PCB is
defect.
Indoor unit control PCB is
faulty.
Remote controller is faulty.
The Y lines in the remote
Are communications lines CnI 1-2
controller is disconnected.
between the outdoor unit control PCB
and inverter control PCB connected?
Fix the inter connection
wiring accordingly
Measure the voltage between CnI
( for 802 and 1002) on the communications
connector (See pages 266 to 269.)
Outdoor unit
control PCB is
defect.
Outdoor unit control
NO
Is the outdoor fan Replace the outdoor
motor faulty?
YES
Note (1) LED Colors
Connection line is
defect (disconnected),
noise.
NO
Is the fuse on the indoor unit
control PCB OK?
NO
Is the voltage on the outdoor
unit's transformer secondary
side (red – red) AC15V (14V) ?
Is the voltage between the red and
Repair the
NO
black wires in the remote
connection
controller DC10~11V when the
lines.
remote controller is disconnected?
The indoor/outdoor
control PCB is faulty.
Approx.
The remote controller
0V DC
is faulty.
The X or Z lines in
controller
the remote controller
are disconnected.
Outdoor unit control
Note (1) Values in ( ) show in the case of
PCB defect
Approx. 0V DC
Connection wires are
faulty (disconnection)
Noise
(1)
NO
A
flashing?
YES
NO
Connect it.
YES
DC approx. 0V
and
DC approx. 12V
Connection
lines are
disconnected.
PCB is defect.
fan motor
402~602: Yellow LED
302, 802, 1002: Green LED
NO
Exchange
the fuse
YES
(1)
NO
Transformer
defect
YES
NO
The remote
controller
wires are
short
YES
circuited.
Remote
defect
the FDKN series.
250
- -
(1)
Diagnosis if the
inverter PCB LED
is OFF
Turn OFF the power
supply once and ON
A
again 3 minute later.
Does it
operate
normally?
NO
Note (2) Models 302~602 only.
(2)
Yes Does the fuse on the power
supply line [30A blown].
NO
Is the noise filter secondary
side AC 220 ~ 240V?
YES
Are the connection lines
between the noise filter and
inverter PCB good?
YES
Are the wiring for reactor
connected correctly?
YES
Is the outdoor fan motor faulty?
YES
Replace the
inverter PCB.
Check the inverter before replacing the power fuse.
Is there a short between
phases in the noise filter?
NO
Is there a short between phases in
the inverter PCB input terminals?
NO
Is the power transistor module
broken or burned out?
NO
Is the reactor faulty?
NO
Is the electrolytic capacitor
anomalous?
NO
Replace the power
supply fuse.
NO
Replace the
noise filter.
Connect the
NO
lines
correctly.
Connect/
NO
replace the
reactor.
Replace the
NO
outdoor fan
motor
YES
Replace the
noise filter.
YES
YES
Replace the
inverter PCB.
YES
Replace the
reactor.
YES
Replace the
electrolytic
capacitor.