Mitsubishi Electric PUHZ-SHW112VAA, Руководство по обслуживанию

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Check code Abnormal point and detection method
Cause Judgment and action
U5
(4230)
Temperature of heat sink
Abnormal if TH8 detects temperature indi-
cated below.
SW75, 100V, SHW80, 112V ··············78
:
SW75, 100Y, SHW80, 112Y ··············85
:
TH8: Thermistor <Heat sink>
1
The outdoor fan motor is locked.
2
Failure of outdoor fan motor
3
Air flow path is clogged.
4
Rise of ambient temperature
5
Defective thermistor
6
Defective input circuit of
outdoor power circuit board
7
Failure of outdoor fan drive circuit
12
Check outdoor fan.
3
Check air flow path for cooling.
4
Check if there is something which causes
temperature rise around outdoor unit.
(Upper limit of ambient temperature is 46
:
.)
Turn off power, and on again to check if U5 is
displayed within 30 minutes.
If U4 is displayed instead of U5, follow the
action to be taken for U4.
5
Check resistance value of TH8 or tempera-
ture by microprocessor. (TH8: Refer to
"9-4. HOW TO CHECK THE PARTS".)
(SW2 on A-Control Service Tool: Refer to "9-7.
FUNCTION OF SWITCHES, CONNECTORS
AND JUMPERS".)
6
Replace outdoor power circuit board.
7
Replace outdoor controller circuit board.
U4
(TH3:5105)
(TH6:5107)
(TH7:5106)
(TH8:5110)
(TH32:5105)*
Open/short of outdoor unit thermistors
(TH3, TH32 (PUHZ-SHW only), TH6, TH7,
and TH8)
Abnormal if open or short is detected
during compressor operation.
Open detection of TH3, TH32 (PUHZ-
SHW only) and TH6 is inoperative for 10
seconds to 10 minutes after compressor
starting and 10 minutes after and during
defrosting.
Note: Check which unit has abnormality in
its thermistor by switching the mode
of SW2. (PAC-SK52ST)
(Refer to "9-7. FUNCTION OF
SWITCHES, CONNECTORS AND
JUMPERS".)
1
Check connection of connector (TH3, TH32*,
TH7/6) on the outdoor controller circuit board.
Check connection of connector (CN3) on the
outdoor power circuit board. Check breaking of
the lead wire for TH3, TH32*, TH6, TH7, TH8.
Refer to "9-6.TEST POINT DIAGRAM".
2
Check resistance value of TH3, TH32*,
TH6,TH7,TH8 or check temperature by
microprocessor.
(TH3,TH6,TH7,TH8: Refer to "9-6.TEST
POINT DIAGRAM".) (SW2 on A-Control
Service Tool: Refer to "9-7. FUNCTION
OF SWITCHES, CONNECTORS AND
JUMPERS".)
3
Replace outdoor controller circuit board.
Note: Emergency operation is available in case of
abnormalities of TH3, TH32 (PUHZ-SHW
only), TH6 and TH7.
1
Disconnection or contact failure
of connectors
Outdoor controller circuit board :
TH3, TH32 (PUHZ-SHW
only), TH7/6
Outdoor power circuit board :
CN3
2
Defective thermistor
3
Defective outdoor controller
circuit board
( )
U6
(4250)
Power module
Check abnormality by driving power module
in case overcurrent is detected.
(UF or UP error condition)
1
Outdoor 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 circuit board
1
Open stop valve.
2
Check facility of power supply.
3
Correct the wiring (U
•
V
•
W phase) to compressor. Refer to "9-6.
TEST POINT DIAGRAM" (Outdoor power circuit board).
4
Check compressor referring to "9-4. HOW TO
CHECK THE PARTS".
5
Replace outdoor power circuit board.
U7
(1520)
Too low superheat due to low discharge
temperature
Abnormal if discharge superheat is
continuously detected less than or equal
to −15
:
for 3 minutes even though linear
expansion valve has minimum open pulse
after compressor starts operating for 10
minutes.
1
Disconnection or loose
connection of discharge
temperature thermistor (TH4)
2
Defective holder of discharge
temperature thermistor
3
Disconnection or loose connection
of linear expansion valve’s coil
4
Disconnection or loose connection
of linear expansion valve’s connector
5
Defective linear expansion valve
12
Check the installation conditions of
discharge temperature thermistor (TH4).
3
Check the coil of linear expansion valve.
Refer to "9-5. HOW TO CHECK THE
COMPONENTS".
4
Check the connection or contact of LEV-A and
LEV-B on outdoor controller circuit board.
5
Check linear expansion valve. Refer to "9-4.
HOW TO CHECK THE PARTS".
Thermistors
Open detection Short detection
Symbol Name
TH3,TH32* Thermistor <Liquid>, <Suction> (PUHZ-SHW only) −40 °C or below 90 °C or above
TH6 Thermistor <2-phase pipe> −40 °C or below 90 °C or above
TH7 Thermistor <Ambient> −40 °C or below 90 °C or above
TH8 Thermistor <Heat sink> −35 °C or below 102 °C or above
U8
(4400)
Outdoor fan motor
Abnormal if rotational frequency of the fan motor
is not detected during DC fan motor operation.
Fan motor rotational frequency is abnormal if;
• 100 rpm or below detected continuously
for 15 seconds at 20
:
or more outside
air temperature.
• 50 rpm or below or 1500 rpm or more
detected continuously for 1 minute.
1
Failure in the operation of the
DC fan motor
2
Failure in the outdoor circuit
controller board
1
Check or replace the DC fan motor.
2
Check the voltage of the outdoor circuit
controller board during operation.
3
Replace the outdoor circuit controller board.
(When the failure is still indicated even after
performing the action
1
above.)
*PUHZ-SHW only
OCH651