Mitsubishi Electric Mr Slim PUHZ-RP50VHA4 Service Manual page 54

Abnormal points and detection method
Error Code
Compressor overcurrent interruption
Abnormal if overcurrent DC bus or com-
pressor 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 control-
ler cannot receive normally any trans-
mission 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)
E0
1 Abnormal if indoor controller board can
or
not receive normally any data from
E4
remote controller board or from other
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)
Remote controller control board
1 Abnormal if data cannot be normally
read from the nonvolatile memory of the
remote controller control board.
E1
(Error code: E1)
or
2 Abnormal if the clock function of remote
E2
controller cannot be normally operated.
(Error code: E2)
OCH451D
Case
1 Stop valve of outdoor unit is
closed.
2 Decrease of power supply volt-
age
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 out-
door 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 receiv-
ing circuit of indoor controller
board of refrigerant address "0"
6 Noise has entered into the
transmission wire of remote
controller.
1 Defective remote controller
54
Judgment and action
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U
V W phase) to com-
• •
pressor. Refer to 11-9 (Outdoor power circuit
board).
4 Check indoor/outdoor fan.
5 Solve short cycle.
6 Replace outdoor controller circuit board.
7 Check compressor. Refer to 11-6.
* Before the replacement of the outdoor con-
troller 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 volt-
age check with same performing frequency.
8 Replace outdoor power circuit board
9 Check the dip switch setting of outdoor con-
troller 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 control-
ler: 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 con-
trollers 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 "RC E3" or "ERC 00-66" is dis-
played, 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.
1 Replace remote controller.