Mitsubishi MXZ-8B140VA Technical & Service Manual page 32

Check code Abnormal point and detection method
Detailed
Input current sensor error/
codes
L1-phase open error
• Decrease in input current
through outdoor unit to 0.1A
only if operation frequency is
more than or equal to 40Hz
or compressor current is more
than or equal to 6A.
04
Abnormal power synchronous
U9
signal
(4220)
• No input of power synchronous
signal to power circuit board
• Power synchronous signal
of 44 Hz or less, or 65 Hz or
08
more is detected on power
circuit board.
PFC/IGBT error
(Undervoltage)
• When Compressor is running,
20
DC bus voltage stays at 310V or
lower for consecutive 10 seconds
(V model only)
Compressor overcurrent interruption
(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
after compressor starts operating.
UF
(4100)
Current sensor error
Abnormal if current sensor detects - 1.5A
to 1.5A during compressor operation. (This
error is ignored in case of test run mode.)
UH
(5300)
Abnormal if input current exceeds 38 A or
34A continuously 10 seconds. (Current sen-
sor on noise filter board detects input current)
Low pressure (63L operated)
Abnormal if 63L is operated (under-
0.03MPa) during compressor operation.
63L: Low-pressure switch
UL
(1300)
OCH480D
Case
1 L 1-phase open (Y model)
2 D isconnection or loose connection
between TB1 and outdoor noise filter
circuit board (Y model)
3 D isconnection or loose connection of
CN5 on the outdoor power circuit board/
CNCT on the outdoor noise filter board
4 D efective ACCT (AC current trans)
on the outdoor noise filter circuit
board (Y model)
5 D efective input current detection
circuit in outdoor power circuit board
6 D efective outdoor controller circuit board
1 D istortion of power source voltage,
noise superimposition.
2 D isconnection or loose connection of
earth wiring
3 D isconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board
4 D efective power synchronous signal
circuit in outdoor controller circuit board
5 D efective power synchronous signal
circuit in outdoor power circuit board
1 I ncorrect switch settings on the
outdoor controller circuit board for
model select
2 D efective outdoor power circuit board
3 D efective outdoor controller circuit
board
1 Stop valve is closed.
2 Decrease of power supply
voltage
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective compressor
5 Defective outdoor power board
1 Disconnection of compressor
wiring
2 Defective circuit of current
sensor on outdoor power
circuit board
1 Decrease of power supply voltage
1 Stop valve of outdoor unit is closed
during operation.
2 Disconnection or loose connection
of connector (63L) on outdoor con-
troller board
3 Disconnection or loose connection
of 63L
4 Defective outdoor controller board
5 Leakage or shortage of refrigerant
6 Malfunction of linear expansion
valve
32
Judgment and action
1 C heck the field facility for the power
supply. (Y model)
2 C heck the wiring between TB1 and out-
door noise filter circuit board. (Y model)
3 Check CN5/CNCT wiring. (Y model)
4 R eplace outdoor noise filter circuit
board. (Y model)
5 Replace outdoor power circuit board.
6 Replace outdoor controller circuit board.
1 C heck the field facility for the power
supply.
2 Check earth wiring.
3 Check CN2 wiring.
4 Replace outdoor controller circuit board.
5 Replace outdoor power circuit board.
1 Correction of a model select
2 Replace outdoor power circuit board.
3 Replace outdoor controller circuit board.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor.
Refer to "8-7. TEST POINT DIAGRAM".
4 Check compressor.
Refer to "8-6. HOW TO CHECK THE
PARTS".
5 Replace outdoor power circuit board.
1 Correct the wiring (U·V·W phase) to
compressor. Refer to "8-7. TEST POINT
DIAGRAM".
2 Replace outdoor power circuit board.
1 Check the facility of power supply.
1 Check stop valve.
2–4 Turn the power off and on again to
check if F3 is displayed on restart-
ing.
If F3 is displayed, follow the F3 pro-
cessing direction.
5 Correct to proper amount of refrigerant.
6 Check linear expansion valve. Refer to
"8-6. HOW TO CHECK THE PARTS".