Mitsubishi Electric PUZ-HWM140VHA Service Manual page 25

Check Code Abnormal point and detection method
Overheat protection
Abnormal if outdoor pipe thermistor (TH3)
detects 70°C or more or condensing
temperature of pressure sensor (63HS)
detects 70°C or more during compressor
Ud
operation.
(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 or input current error
· Abnormal if current sensor detects −1.0 A
to 1.0 A during compressor operation.
(This error is ignored during test run.)
UH
·Abnormal if 40 A of input current is detected
(5300)
or 39 A or more of input current is detected
for 10 seconds continuously. (HWM140V
only)
Compressor overcurrent interruption
Abnormal if overcurrent DC bus or
compressor is detected after compressor
starts operating for 30 seconds.
UP
(4210)
Remote controller transmission error
(E0)/signal receiving error (E4)
1 Abnormal if main or sub remote
controller cannot receive any
transmission normally from Interface
unit/Flow temp. controller of refrigerant
address "0" for 3 minutes.
(Check code: E0)
E0
2 Abnormal if sub-remote controller could
or
not receive any signal for 2 minutes.
E4
(Check code: E0)
(6831
or
1 Abnormal if Interface/Flow temp.
6834)
controller board cannot receive any
data normally from remote controller
board or from other Interface/Flow temp.
controller board for 3 minutes. (Check
code: E4)
2 Interface/Flow temp. controller board
cannot receive any signal from remote
controller for 2 minutes. (Check code: E4)
OCH748
Cause
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
4 Defective pressure sensor
1 Decrease of power supply voltage
2 Looseness, disconnection or
reverse of compressor wiring
connection
3 Defective compressor
4 Defective outdoor power board
5 Decreased water flow
6 Clogged filter of water pipe
7 Clogged plate heat exchanger
8 Locked water pump
9 Malfunction of water pump
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 Decrease of power supply voltage
2 Looseness, disconnection or
reverse of compressor wiring
connection
3 Defective fan of outdoor units
4 Short cycle of indoor/outdoor
units
5 Defective input circuit of out-
door controller board
6 Defective compressor
7 Decreased water flow
8 Clogged filter of water pipe
9 Clogged plate heat exchanger
Locked water pump
0
Malfunction of water pump
1
1 Contact failure at transmission
wire of remote controller
2 All remote controllers are set
as "sub" remote controller.
In this case, E0 is displayed
on remote controller, and E4
is displayed at LED (LED1,
LED2) on the outdoor control-
ler circuit board.
3 Miswiring of remote controller
4 Defective transmitting receiv-
ing circuit of remote controller
5 Noise has entered into the
transmission wire of remote
controller.
25
Judgment and action
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.
4 Check pressure by microprocessor.
(Pressure sensor/ 63HS)
(SW2: Refer to "9-8. OUTDOOR UNIT
OPERATION MONITOR FUNCTION".)
1 Check facility of power supply.
2 Correct the wiring (U V W phase) to
• •
compressor.
Refer to "9-7. TEST POINT DIAGRAM"
(Outdoor power circuit board).
3 Check compressor. Refer to
CHECK THE PARTS"
4 Replace outdoor power circuit board.
–
9 Check water circuit and repair the defect.
5
1 Correct the wiring (U V W phase) to compres-
• •
sor. Refer to "9-7. 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 facility of power supply.
2 Correct the wiring (U V W phase) to
• •
compressor. Refer to "9-7. TEST POINT
DIAGRAM" (Outdoor power circuit board).
3 Check outdoor fan.
4 Solve short cycle.
5 Replace outdoor controller circuit board.
6 Check compressor.
Refer to "9-5. HOW TO CHECK THE PARTS".
Note: Before the replacement of the outdoor
controller circuit board, disconnect the
wiring to compressor from the outdoor
power circuit board and check the output
voltage among phases, U, V, W, during
test run. No defect on board if voltage
among phases (U-V, V-W and W-U) is
same. Make sure to perform the voltage
check with same performing frequency.
7–1 Check water circuit and repair the defect.
1 Check disconnection or looseness of
Interface unit/Flow temp. controller unit or
transmission wire of remote controller.
2 Set one of the remote controllers "main" if
there is no problem with the action above.
3 Check wiring of remote controller.
• Total wiring length: max. 500 m
(Do not use cable with 3 or more cores.)
• The number of connecting remote controller
(Refer to the indoor unit's Installation Manual.)
If the cause of trouble is not in 1–3 above,
4 Diagnose remote controllers.
a) When "OK" is displayed, remote controllers
have no problem.
Turn the power off, and on again to check. If
abnormality occurs again, replace Interface/
Flow temp. controller board.
b) When "NG" is displayed, replace remote
controller.
c) When "E3" or "00–66" is displayed, noise
may be causing abnormality.
"9-5. HOW TO