68 • vacon CABLING AND CONNECTIONSTel. +358 (0)201 2121 • Fax +358 (0)201 212 20566.1.7 Cable and motor insulation checks1. Motor cable insulation checksDisconnect the motor cable from terminals U, V and W of the frequency converter and from the motor.Measure the insulation resistance of the motor cable between each phase conductor as well asbetween each phase conductor and the protective ground conductor. The insulation resistance must be>1MΩ.2. Mains cable insulation checksDisconnect the mains cable from terminals L1, L2 and L3 of the frequency converter and from themains. Measure the insulation resistance of the mains cable between each phase conductor as well asbetween each phase conductor and the protective ground conductor. The insulation resistance must be>1MΩ.3. Motor insulation checksDisconnect the motor cable from the motor and open the bridging connections in the motor connectionbox. Measure the insulation resistance of each motor winding. The measurement voltage must equal atleast the motor nominal voltage but not exceed 1000 V. The insulation resistance must be >1MΩ.
