Mitsubishi Electric PUHZ-HRP71VHA Service Manual page 46

Abnormal point and detection method
Error Code
Low pressure (63L operated)
Abnormal if 63L is operated (under
-0.03MPa) during compressor operation.
63L: Low-pressure switch
UL
(1300)
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 normally
any transmission from indoor unit of
refrigerant address "0" for 3 minutes.
(Error code : E0)
2 Abnormal if sub remote controller could
not receive any signal for 2 minutes.
(Error code: E0)
1 Abnormal if indoor controller board can
E0
not receive normally any data from
or
remote controller board or from other
E4
indoor controller board for 3 minutes.
(Error code: E4)
2 Indoor controller board cannot receive
any signal from remote controller for 2
minutes. (Error code: E4)
OCH425F
Case
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 Stop valve of outdoor unit is
closed.
2 Decrease of power supply
voltage
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective fan of indoor/outdoor
units
5 Short cycle of indoor/outdoor
units
6 Defective input circuit of
outdoor controller board
7 Defective compressor
8 Defective outdoor power circuit
board
9 Dip switch setting difference of
outdoor controller circuit board
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 controller
circuit board.
3 Miswiring of remote controller
4 Defective transmitting receiving
circuit of remote controller
5 Defective transmitting receiving
circuit of indoor controller board
of refrigerant address "0"
6 Noise has entered into the
transmission wire of remote
controller.
46
Judgment and action
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 process-
ing direction.
5 Correct to proper amount of refrigerant.
6 Check linear expansion valve.
Refer to 11-6.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor. Refer to 11-9 (Outdoor power
circuit board).
4 Check indoor/outdoor fan.
5 Solve short cycle.
6 Replace outdoor controller circuit board.
* 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 Check compressor. Refer to 11-6.
8 Replace outdoor power circuit board.
9 Check the dip switch setting of outdoor
controller circuit board.
1 Check disconnection or looseness of indoor
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. 500m
(Do not use cable o 3 or more.)
• The number of connecting indoor units:
Max. 16 units
• The number of connecting remote
controller: Max. 2 units
When it is not the above-mentioned problem of
1~3
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 generates again, replace
indoor controller board.
b) When "RC NG" is displayed,
Replace remote controller.
c) When "RCE3" or "ERC00-66" is displayed,
noise may be causing abnormality.
* If the unit is not normal after replacing
indoor controller board in group control,
indoor controller board of address "0"
may be abnormal.