Mitsubishi Electric CMB-WM108V-AA Service Handbook page 153

[ VIII Troubleshooting ]
4115
1. Error Code
4115
Power supply signal sync error
2. Error definition and error detection method
The frequency cannot be determined when the power is switched on.
3. Cause, check method and remedy
(1) Power supply error
(2) Noise filter problem
Coil problem
Circuit board failure
(3) Faulty wiring
(4) Wiring failure
Between noise filter CN3 and noise filter CN2 and con-
trol board CNAC
(5) Control board failure
5102
1. Error Code
5102
Incorrect pipe connection (indoor unit)
2. Error definition and error detection method
Water inlet and outlet pipes are connected in reverse. (Detected only during commissioning)
1) The formula "Water inlet pipe temperature (TH22) + 4°C < Water outlet pipe temperature (TH23)" is met after at least 15 min-
utes have passed after the operation mode was changed from Cooling/Dry to Heating during commissioning.
2) The formula "Water inlet pipe temperature (TH22) + 4°C < Water outlet pipe temperature (TH23)" is met after at least 10 min-
utes have passed after the operation mode was changed from the mode other than Cooling/Dry to Heating during commis-
sioning.
3) The formula "Water inlet pipe temperature (TH22) > Water outlet pipe temperature (TH23) + 4°C" is met after at least 15 min-
utes have passed after the operation mode was changed from Heating to Cooling/Dry during commissioning.
4) The formula "Water inlet pipe temperature (TH22) > Water outlet pipe temperature (TH23) + 4°C" is met after at least 10 min-
utes have passed after the operation mode was changed from the mode other than Heating to Cooling/Dry during commis-
sioning.
This error may not be detectable under certain operating conditions due to a lack of temperature differential.
3. Cause, check method and remedy
(1) Incorrect water pipe connection
(2) Thermistor failure
(3) Connector contact failure
(4) Disconnected wire or partial disconnected thermistor
wire
(5) Indoor board (detection circuit) failure
HWE1708A
Cause
Cause
Check method and remedy
Check the voltage of the power supply terminal
block (TB1).
Check the coil connections.
Check for coil burnout.
Confirm that the voltage at the CN3 connector is
198 V or above.
Check fuse F01 on the control board.
Confirm that the voltage at the control board con-
nector CNAC is 198 V or above.
If none of the items described above is applicable,
and if the trouble reappears even after the power is
switched on again, replace the control board.
Check method and remedy
Check that the water inlet and outlet pipes are not
connected in reverse.
Check the thermistor resistor.
0°C [32°F]: 15 kΩ
10°C [50°F]: 9.7 kΩ
20°C [68°F] : 6.4 kΩ
30°C [86°F] : 4.3 kΩ
40°C [104°F] : 3.1 kΩ
Check the connector contact.
When no fault is found, the indoor board is a failure.
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