Motor thermal load monitoring (I²xt)

What does it mean?

Sensorless motor thermal load monitoring (I²xt), available from software version 8.0. OC6 = fixed TRIP (threshold C0120); OC8 = adjustable advance warning (TRIP / warning / off via C0606, threshold C0127). The current load is shown in C0066.

Common causes

• The motor is continuously or repeatedly loaded above its rated current. OC8 is typically used as an advance warning before OC6 trips.

How to fix it

• Check the motor and drive dimensioning. Adjust the thresholds in C0120 (OC6) / C0127 (OC8) and the OC8 response in C0606. The error can only be reset after the I²xt load drops 5% below the threshold.

After troubleshooting: de-energise the device completely (disconnect the 24 V supply and discharge the DC bus) before opening the covers.