Cause : Motor thermistor over temp comes when the thermistor might be disconnected. The thermistor or the thermistor connection has been disconnected. Parameter 128 allows a choice of whether the frequency converter is to give a warning or an alarm.

• Check for motor overheating.
• Check if the motor is mechanically overloaded.
• The thermistor or the thermistor connection has been disconnected. Parameter 128 allows a choice of whether the frequency converter is to give a warning or an alarm. Check that the thermistor has been correctly connected between terminal 53 or 54 (analogue voltage input) and terminal 50 (+ 10 Volts supply).
• If using a thermal switch or thermistor, check that the programming if matches sensor wiring.