Mitsubishi Electric PUHZ-W50VHA Service Manual page 59

Check Code Abnormal point and detection method
Current sensor error or input current error
· A bnormal 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
or 37 A or more of input current is detected
for 10 seconds continuously. (HW140V
only)
Low pressure (63L operated)
Abnormal if 63L is operated (under -0.03
MPa) during compressor operation.
63L: Low pressure switch
UL
Compressor overcurrent interruption
Abnormal if overcurrent DC bus or
compressor is detected after compressor
starts operating for 30 seconds.
UP
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)
2 Abnormal if sub-remote controller could
not receive any signal for 2 minutes.
E0
(Check code: E0)
or
E4
1 Abnormal if Interface/Flow temp.
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)
Remote controller control board
1 Abnormal if data cannot be read nor-
mally from the nonvolatile memory of
E1
the remote controller control board.
or
(Check code: E1)
E2
2 Abnormal if the clock function of remote
controller cannot be operated normally.
(Check code: E2)
OCH439M
Cause
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
1 Decrease of power supply volt-
age
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.
1 Defective remote controller
59
Judgment and action
1 Correct the wiring (U V W phase) to compres-
• •
sor. Refer to "9-6. 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 "9-5. HOW TO CHECK THE
COMPONENTS".
1 Check facility of power supply.
2 Correct the wiring (U V W phase) to
• •
compressor. Refer to "9-6. 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 "9-4. 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 × 3 or more.)
• 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 "RC 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 "RC NG" is displayed, replace remote
controller.
c) When "RC E3" or "ERC 00–66" is displayed,
noise may be causing abnormality.
1 Replace remote controller.