InstallationM-Max Series Adjustable Frequency Drive MN04020003E—October 2013 www.eaton.com 49Insulation TestingThe M-Max series frequency inverters are tested, deliveredand require no additional testing.WARNINGOn the control signal and the connection terminals of thefrequency inverter, no leakage resistance tests are to beperformed with an insulation tester.WARNINGWait at least 5 minutes after switching the supplyvoltage off before you disconnect a connection on theconnection terminals (L1, L2/N, L3, U/T1, V/T2, W/T3,R+, R–) of the frequency inverter.If insulation testing is required in the power circuit of thePDS, you must consider the following measures.Testing the Motor Cable InsulationDisconnect the motor cable from connection terminals U/T1,V/T2 and W/T3 of the frequency inverter and from the motor(U, V, W). Measure the insulation resistance of the motorcable between the individual phase conductors and betweenthe phase conductor and the protective conductor.The insulation resistance must be greater than 1M ohm.Testing the Input Cable InsulationDisconnect the power cable from the input supply networkand from connection terminals L1, L2/N and L3 of thefrequency inverter. Measure the insulation resistance of theinput cable between the individual phase conductors andbetween each phase conductor and the protectiveconductor.The insulation resistance must be greater than 1M ohm.Testing the Motor InsulationDisconnect the motor cable from the motor (U, V, W) andopen the bridge circuits (star or delta) in the motor terminalbox. Measure the insulation resistance of the individualmotor windings. The measurement voltage must at leastmatch the rated voltage of the motor but is not to exceed1000V.The insulation resistance must be greater than 1M ohm.Consider the information from the motor manufacturer intesting the insulation resistance.
