Mitsubishi Electric PEAD Series Service Manual page 33

TROUBLESHOOTING
Error Code Abnormal point and detection method
Abnormality of pipe temperature
thermistor / Condenser-Evaporator
(TH5)
1 The unit is in three-minute resume
protection mode if short/open of
thermistor is detected. Abnormal if the
unit does not get back to normal within
three minutes. (The unit returns to
normal operation, if it has normally
P9
reset.)
2 Constantly detected during cooling,
drying, and heating operation (except
defrosting)
Remote controller transmission
error(E0)/signal receiving error(E4)
1 Abnormal if main or sub remote
controller can not receive normally any
transmission from indoor unit of
refrigerant address "0" for three minutes.
(Error code : E0)
2 Abnormal if sub remote controller could
not receive for any signal for two
minutes. (Error code: E0)
1 Abnormal if indoor controller board can
not receive normally any data from
remote controller board or from other
indoor controller board for three minutes.
E0
(Error code: E4)
or 2 Indoor controller board cannot receive
E4
any signal from remote controller for two
minutes. (Error code: E4)
Remote controller transmission
error(E3)/signal receiving error(E5)
1 Abnormal if remote controller could not
find blank of transmission path for six
seconds and could not transmit.
(Error code: E3)
2 Remote controller receives transmitted
data at the same time, compares the
data, and when detecting it, judges
different data to be abnormal 30
E3 continuous times. (Error code: E3)
or
1 Abnormal if indoor controller board could
E5
not find blank of transmission path.
(Error code: E5)
2 Indoor controller board receives
transmitted data at the same time,
compares the data,and when detecting
it, judges different data to be abnormal
30 continuous times. (Error code: E5)
HWE16080
Cause
1 Defective thermistor
characteristics
2 Contact failure of connector
(CN44) on the indoor controller
board (Insert failure)
3 Breaking of wire or contact
failure of thermistor wiring
4 Temperature of thermistor is
defective refrigerant circuit.
5 Defective indoor controller
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 Mis-wiring 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.
1 Two remote controllers are set
as "main."
(In case of 2 remote
controllers)
2 Remote controller is connected
with two indoor units or more.
3 Repetition of refrigerant
address
4 Defective transmitting receiving
circuit of remote controller
5 Defective transmitting receiving
circuit of indoor controller
board
6 Noise has entered into
transmission wire of remote
controller.
33
Countermeasure
1–3 Check resistance value of thermistor.
For characteristics, refer to (P1) above.
2 Check contact failure of connector (CN44)
on the indoor controller board.
Refer to 10-5.
Turn the power on and check restart after
inserting connector again.
4 Operate in test run mode and check pipe
<condenser / evaporator> temperature.
If pipe <condenser / evaporator>
temperature is extremely low (in cooling
mode) or high (in heating mode),
refrigerant circuit may have defect.
5 When no problems are found in 1-4
above, replace the indoor unit control
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 × 3 or more)
The number of connecting indoor units:
max.16units
The number of connecting remote
controller: max.2units
When it is not the above-mentioned problem
of 1~3
4 Diagnose remote controllers.
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 "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.
1 Set a remote controller to main, and the
other to sub.
2 Remote controller is connected with only
one indoor unit.
3 The address changes to a separate setting.
4~6 Diagnose remote controller.
controllers have no problem.
Turn the power off, and on again to check.
When becoming abnormal again, replace
indoor 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.