Mitsubishi Electric MR. SLIM PUZ-M100VKA2, Service Manual

Page: 35 / 116

35
OCH773
UF
(4100)
Compressor overcurrent interruption
(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
after compressor starts operating.
1
Stop valve is closed.
2
Decrease of power supply
voltage
3
Looseness, disconnection or
reverse of compressor wiring
connection
4
Defective compressor
5
Defective outdoor power board
6
Dip switch setting difference of
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 "9-8. TEST POINT DIAGRAM
(Outdoor power circuit board)".
4
Check compressor.
Refer to "9-5. HOW TO CHECK THE PARTS".
5
Replace outdoor power circuit board.
6
Check the DIP switch setting of outdoor con -
troller circuit board.
Refer to "Model Select" section at (1) Function
of switches" in "9-9. FUNCTION OF SWITCHES,
CONNECTORS AND JUMPERS".
Ud
(UD)*
(1504)
Over heat protection
Abnormal if outdoor pipe thermistor (TH3)
detects 70°C or more during compressor
operation.
1
Defective outdoor fan (fan
motor) or short cycle of outdoor
unit during cooling operation
2
Defective outdoor pipe
thermistor (TH3)
3
Defective outdoor controller
board
1
Check outdoor unit air passage.
23
Turn the power off and on again to check
the check code. If U4 is displayed, follow the
U4 processing direction.
*The check code in the parenthesis indicates
PAR-3xMAA ("x" represents 0 or later) model.
Check code Abnormal point and detection method Cause
Judgment and action
U9
(4220)
From the previous page.
UH
(5300)
Current sensor error
● Abnormal if 38 A of incurrent is detected
or 34A or more of input current is
detected for 10seconds continuously.
1
Defective circuit of current
sensor on outdoor power circuit
board
2
Decrease of power supply
voltage
1
Replace outdoor power circuit board.
2
Check the facility of power supply.
Detailed
codes
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowing:
a) Increase in DC bus voltage
to 460 V
b) Decrease in PFC control
voltage to 12 V DC or lower
c) Increase in input current
(PUZ-M·VKA2 only)
1
Abnormal increase in power
source voltage
2
Decrease in power source
voltage, instantaneous stop.
3
Disconnection of compressor wiring
4
Misconnection of reactor (DCL)
5
Defective outdoor power circuit
board
6
Defective Reactor(DCL)
7
Disconnection or loose
connection of CN2 on the
outdoor power circuit board/
controller circuit board
12
Check the field facility for the power supply.
3
Correct the wiring (U.V.W phase) to
compressor. Refer to "9-8. TEST POINT
DIAGRAM".
4
Correct the wiring of reactor (DCL)
5
Replace outdoor power circuit board.
6
Replace Reactor (DCL).
7
Check CN2 wiring.
UL
(1300)
Low pressure
Abnormal if the following conditions are
detected for continuously 3 minutes. Note
that it applies when the compressor accu -
mulated operating time is under 30 min-
utes, and 7 minutes has passed after the
compressor operation.
TH33 - TH4
]
20 °C and TH33 > 80 °C
Thermistors:
TH33: Comp. Surface temperature
TH4: Discharge temperature
TH5: Indoor 2-phase pipe temperature
TH7: Ambient temperature
1
Stop valve of outdoor unit is
closed during operation.
2
Leakage or shortage of
refrigerant
3
Malfunction of linear expansion
valve
4
Clogging with foreign objects in
refrigerant circuit
Note:
Clogging occurs in the parts
which become below freezing
point when water enters in
refrigerant circuit.
1
Check stop valve.
2
Check intake superheat.
Check leakage of refrigerant.
Check additional refrigerant.
3
Check linear expansion valve.
Refer to "9-5. HOW TO CHECK THE
PARTS".
4
After recovering refrigerant, remove water
from entire refrigerant circuit under vacuum
more than 1 hour.
10
20
PFC/IGBT error
(Undervoltage)
• When Compressor is running,
DC bus voltage stays at 310V
or lower for consective 10 sec -
onds.
(PUZ-M·VKA2 only)
1
Incorrect switch settings on the
outdoor controller circuit board
for model select
2
Defective outdoor power circuit
board
3
Defective outdoor controller
circuit board
1
Correction of a model select
2
Replace outdoor power circuit board.
3
Replace outdoor controller circuit board.