Electrolux W4105N, Service Manual

Page: 38 / 122

38
Troubleshooting
Fault code 38, HIGH DC VOLTAGE
This fault code is generated by the motor control unit. The motor control
unit constantly measures the voltage over the mains input. If the voltage
is too high (= exceeds a certain limit), the motor control unit will shut off
the current to the motor. Once the motor has stopped (= the tacho sensor
indicates that the motor is stationary), the motor control unit checks to
see whether the input voltage is still high. If it is, a fault code is activated:
”HIGH DC VOLTAGE”.
The reason for this fault code being activated can be high mains voltage
(e.g. power surge). Further information can be obtained by studying the
contents of ”FC FAULT LOGGER”:
• OVERVOLTAGE 2 (specifies how many times fault code 38 has been
active)
• OVERVOLTAGE 1 (specifies how many times the voltage limit has been
exceeded. The difference between overvoltage 1 and overvoltage 2
gives the number of times overvoltage 1 has occurred without it being
confirmed when the motor has stopped).
• LAST FAULT CODE N/8 (shows the 8 latest fault codes)
Overvoltage registrations can also occur if there is a bad contact in the
tacho signal. Check also the following registers:
• TACHO CUT-OUT LOW RPM (number of short tacho interruptions
during wash rpm)
• TACHO CUT-OUT HIGH RPM (number of short tacho interruptions
during extraction rpm)
Action:
• Check the tacho cables if there are many registrations in the TACHO
CUT-OUT registers.