Planning the electrical installation603. Check that the motor voltage rating meets the application requirements:See notes 6 and 7 below the Requirements table.4. Consult the motor manufacturer before using a motor in a drive system where themotor nominal voltage differs from the AC power source voltage.5. Ensure that the motor insulation system withstands the maximum peak voltage inthe motor terminals. See the Requirements table below for the required motorinsulation system and drive filtering.Example 1: When the supply voltage is 440 V and the drive has a diode supplyand operates in motor mode only, the maximum peak voltage at the motorterminals can be approximated as follows: 440 V × 1.35 × 2 = 1190 V. Check thatthe motor insulation system withstands this voltage.Example 2: When the supply voltage is 440 V and the drive is equipped with anIGBT supply, the maximum peak voltage in the motor terminals can beapproximated as follows: 440 V × 1.41 × 2 = 1241 V. Check that the motorinsulation system withstands this voltage.Protecting the motor insulation and bearingsThe output of the drive comprises – regardless of output frequency – pulses ofapproximately 1.35 times the equivalent mains network voltage with a very short risetime. This is the case with all drives employing modern IGBT inverter technology.The voltage of the pulses can be almost double at the motor terminals, depending onthe attenuation and reflection properties of the motor cable and the terminals. This inturn can cause additional stress on the motor and motor cable insulation.Modern variable speed drives with their fast rising voltage pulses and high switchingfrequencies can cause current pulses that flow through the motor bearings, whichcan gradually erode the bearing races and rolling elements.If the drive is equipped with … … and … … then the motor voltagerating should be …diode supply(ACS800-01, ACS800-U1,ACS800-02, ACS800-U2,ACS800-04, ACS800-04M,ACS800-U4, ACS800-07,ACS800-U7)no resistor braking is used UNfrequent or long-term brake cyclesare usedUACeq1IGBT supply(ACS800-11, ACS800-U11,ACS800-17, ACS800-37)DC link voltage is not increased fromnominal (through parameter settings)UNDC link voltage is increased fromnominal (through parameter settings)UACeq2UN = Rated input voltage of driveUACeq1 = UDC / 1.35UACeq2 = UDC / 1.41UACeq = Equivalent AC power source voltage of drive in V ACUDC = Maximum DC link voltage of drive in V DC. For resistor braking, UDC = 1.21 × nominal DC linkvoltage. For units with IGBT supply: see the parameter value. Note: Nominal DC link voltage is UN × 1.35 orUN × 1.41 in V DC.
