Mitsubishi Electric PUZ-SM100VKA2 Service Manual page 34

From the previous page.
Abnormal point and detection method
Check code
Detailed
PFC error (Overvoltage/
codes
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowing:
a) Increase in DC bus voltage
to 460 V
b) Decrease in PFC control
10
voltage to 12 V DC or lower
c) Increase in input current
(PUZ-SM·VKA2 only)
U9
(4220)
PFC/IGBT error
(Undervoltage)
• When Compressor is running,
DC bus voltage stays at 310V
or lower for consective 10 sec-
20
onds.
(PUZ-SM·VKA2 only)
Over heat protection
Abnormal if outdoor pipe thermistor (TH3)
detects 70°C or more during compressor
Ud
operation.
(UD)*
(1504)
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 38 A of incurrent is detected
UH
or 34A or more of input current is
(5300)
detected for 10seconds continuously.
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
UL
(1300)
Thermistors:
TH33: Comp. Surface temperature
TH4: Discharge temperature
TH5: Indoor 2-phase pipe temperature
TH7: Ambient temperature
OCH774A
Cause
Abnormal increase in power
source voltage
Decrease in power source
voltage, instantaneous stop
Disconnection of compressor wiring
Misconnection of reactor (DCL)
Defective outdoor power circuit
board
Defective Reactor(DCL)
Disconnection or loose
connection of CN2 on the
outdoor power circuit board/
controller circuit board
Incorrect switch settings on the
outdoor controller circuit board
for model select
Defective outdoor power circuit
board
Defective outdoor controller
circuit board
Defective outdoor fan (fan
motor) or short cycle of outdoor
unit during cooling operation
Defective outdoor pipe
thermistor (TH3)
Defective outdoor controller
board
Stop valve is closed.
Decrease of power supply
voltage
Looseness, disconnection or
reverse of compressor wiring
connection
Defective compressor
Defective outdoor power board
Dip switch setting difference of
outdoor controller circuit board
Defective circuit of current
sensor on outdoor power circuit
board
Decrease of power supply
voltage
Stop valve of outdoor unit is
closed during operation.
Leakage or shortage of
refrigerant
Malfunction of linear expansion
valve
Clogging with foreign objects in
refrigerant circuit
Note:
Clogging occurs in the parts
which become below freezing
point when water enters in
refrigerant circuit.
34
Judgment and action
Check the field facility for the power supply.
Correct the wiring (U.V.W phase) to
compressor. Refer to "9-8. TEST POINT
DIAGRAM".
Correct the wiring of reactor (DCL)
Replace outdoor power circuit board.
Replace Reactor (DCL).
Check CN2 wiring.
Correction of a model select
Replace outdoor power circuit board.
Replace outdoor controller circuit board.
Check outdoor unit air passage.
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
Open stop valve.
Check facility of power supply.
Correct the wiring (U V W phase) to
• •
compressor.
Refer to "9-8. TEST POINT DIAGRAM
(Outdoor power circuit board)".
Check compressor.
Refer to "9-5. HOW TO CHECK THE PARTS".
Replace outdoor power circuit board.
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".
Replace outdoor power circuit board.
Check the facility of power supply.
Check stop valve.
Check intake superheat.
Check leakage of refrigerant.
Check additional refrigerant.
Check linear expansion valve.
Refer to "9-5. HOW TO CHECK THE
PARTS".
After recovering refrigerant, remove water
from entire refrigerant circuit under vacuum
more than 1 hour.
.