Method for detecting disconnection of AC phase input of frequency converter of motor drive, and motor drive

摘要

A method for detecting a disconnection of an AC phase input of a three-phase frequency converter of a motor drive from an AC supply, and a motor drive configured to control a frequency converter (100) to supply power to a resistance from a DC intermediate circuit of the frequency converter, monitor a voltage of the DC intermediate circuit during the supplying of power to the resistance, and detect a disconnection of an AC phase input (U1, V1, W1) of the frequency converter (100) from the AC supply (400) on the basis of a fluctuation of the monitored voltage of the DC intermediate circuit (10) of the frequency converter.