Overheat Protection; Abnormal Pressure Of Pressure Sensor; Compressor Overcurrent Interruption; Current Sensor Error Or Input Current Error - Mitsubishi Electric PUHZ-SHW230YKA2 Service Manual

Check Code
Abnormal point and detection method

Overheat protection

Abnormal if outdoor pipe thermistor (TH3),
condensing temperature T
or more during compressor operation.
Ud

Abnormal pressure of pressure sensor

(63HS)
Abnormal if pressure sensor (63HS)
detects 0.1 MPa or less.
Detection is inoperative for 3 minutes after
compressor starting and 3 minutes after
and during defrosting.
UE

Compressor overcurrent interruption

(When compressor is locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
after compressor starts operating.
UF

Current sensor error or input current error

• Abnormal if current sensor detects –1.0A
to 1.0A during compressor operation. (This
error is ignored in case of test run mode.)
UH
Low pressure (63L operated)
Abnormal if 63L is operated (under −0.03
MPa) during compressor operation.
63L: Low pressure switch
UL
OCH594B
1 Defective outdoor fan (fan
motor) or short cycle of outdoor
unit during cooling operation
detects 70:
63HS
2 Defective outdoor pipe
thermistor (TH3), condensing
temperature T
3 Defective outdoor controller
board
1 Disconnection or contact
failure of connector (63HS) on
the outdoor controller circuit
board
2 Defective pressure sensor
3 Defective outdoor controller
circuit board
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 Disconnection of compressor
wiring
2 Defective circuit of current
sensor on outdoor power circuit
board
3 Decrease of power supply
voltage
4 Leakage or shortage of
refrigerant
1 Stop valve of outdoor unit is
closed during operation.
2 Disconnection or loose
connection of connector (63L)
on outdoor controller 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
Case
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.
63HS
1 Check connection of connector (63HS) on
the outdoor controller circuit board.
Check breaking of the lead wire for
thermistor (63HS).
2 Check pressure by microprocessor.
(Pressure sensor/ 63HS)
(SW2: Refer to "8-8. FUNCTION OF
SWITCHES, CONNECTORS AND
JUMPERS".)
3 Replace outdoor controller board.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U
Refer to "8-7. TEST POINT DIAGRAM"
(Outdoor power circuit board).
4 Check compressor.
Refer to
5 Replace outdoor power circuit board.
6 Check the DIP switch setting of outdoor con-
troller circuit board. Refer to "Model Select" in
"1) Function of switches" in "8-8. FUNCTION
OF SWITCHES, CONNECTORS AND
JUMPERS".
1 Correct the wiring (U
compressor. Refer to "8-7. TEST POINT
DIAGRAM" (Outdoor power circuit board).
2 Replace outdoor power circuit board.
3 Check the facility of power supply.
4 Check leakage of refrigerant.
1 Check stop valve.
2–4 Turn the power off and on again to check
if F3 is displayed on restarting.
If F3 is displayed, follow the F3 processing
direction.
5 Correct to proper amount of refrigerant.
6 Check linear expansion valve.
Refer to "8-6. HOW TO CHECK THE
COMPONENTS".
22
Judgment and action
V W phase) to compressor.
• •
"8-5. HOW TO CHECK THE PARTS".
V W phase) to
• •