Remote Controller Transmission Error/Signal Receiving Error(E4); Remote Controller Control Board - Mitsubishi Electric PUHZ-RP250YHA2 Service Manual

Abnormal point and detection method
Error Code
Low pressure (63L worked)(RP250)
Abnormal if 63L is worked (under
-0.03MPa) during compressor operation.
63L: Low-pressure switch
UL
(1300)
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)
Abnormal if main or sub remote con-
troller cannot receive any transmission
normally from indoor unit of refrigerant
address "0" for 3 minutes.
(Error code : E0)
Abnormal if sub-remote controller could
not receive any signal for 2 minutes.
(Error code: E0)
Abnormal if indoor controller board can
not receive any data normally from
E0
remote controller board or from other
or
indoor controller board for 3 minutes.
E4
(Error code: E4)
Indoor controller board cannot receive
any signal from remote controller for 2
minutes. (Error code: E4)

Remote controller control board

Abnormal if data cannot be read nor-
mally from the nonvolatile memory of the
remote controller control board.
E1
(Error code: E1)
or
E2
Abnormal if the clock function of remote
controller cannot be operated normally.
(Error code: E2)
Case
Stop valve of outdoor unit is
closed during operation.
Disconnection or loose con-
nection of connector (63L) on
outdoor controller circuit board
Disconnection or loose connec-
tion of 63L
Defective outdoor controller cir-
cuit board
Leakage or shortage of refrigerant
Malfunction of linear expansion
valve
Stop valve of outdoor unit is
closed.
Decrease of power supply volt-
age
Looseness, disconnection or
converse of compressor wiring
connection
Defective fan of indoor/outdoor
units
Short cycle of indoor/outdoor
units
Defective input circuit of out-
door controller board
Defective compressor
Defective outdoor power circuit
board
Dip switch setting difference of
outdoor controller circuit board
Contact failure at transmission
wire of remote controller
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.
Miswiring of remote controller
Defective transmitting receiving
circuit of remote controller
Defective transmitting receiv-
ing circuit of indoor controller
board of refrigerant address "0"
Noise has entered into the
transmission wire of remote
controller.
Defective remote controller
33
Judgment and action
Check stop valve.
~ 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.
Correct to proper amount of refrigerant.
Check linear expansion valve.
Refer to 10-7.
Open stop valve.
Check facility of power supply.
Correct the wiring (U·V·W phase) to com-
pressor. Refer to 10-9 (Outdoor power circuit
board).
Check indoor/outdoor fan.
Solve short cycle.
Replace outdoor controller circuit board.
Before the replacement of the outdoor control-
ler circuit board, disconnect the wiring to com-
pressor 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.
Check compressor. Refer to 10-6.
Replace outdoor power circuit board.
Check the dip switch setting of outdoor con-
troller circuit board.
Check disconnection or looseness of indoor
unit or transmission wire of remote controller.
Set one of the remote controllers "main", if
there is no problem with the action above.
Check wiring of remote controller.
• Total wiring length: max. 500m
(Do not use cable × 3 or more.)
• The number of connecting indoor units:
max. 16 units
• The number of connecting remote control-
ler: max. 2 units
When the above-mentioned problem of
are not applied
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" is displayed,
d) When "ERC 00-06" is displayed,
If the unit is not normal after replacing
indoor controller board in group control,
indoor controller board of address "0" may
be abnormal.
Replace remote controller.
~