How does the Altivar 61 and Altivar 71 drives measure the line voltage parameter ( ULN ).

The measurement of the line voltage is done by the parameter ULN.

This value display come from the DC bus , ULN = Vbus/rootsquare (2)

The accuracy of the measurement depends of the state using drive

Accuracy with no load < 5%

Accuracy motor loaded is 10%~15%