Mitsubishi Electric fr-e700 series, Instruction Manual

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Electromagnetic compatibility (EMC) Wiring
3 - 56
3.9.4 Inverter-driven 400 V class motor
In the PWM type inverter, a surge voltage attributable to wiring constants is generated at the motor
terminals. Especially for a 400 V class motor, the surge voltage may deteriorate the insulation. When
the 400 V class motor is driven by the inverter, consider the following measures:
●
Rectifying the motor insulation and limiting the PWM carrier frequency according to the wiring
length. For the 400 V class motor, use an insulation-enhanced motor.
– Specify the "400 V class inverter-driven insulation-enhanced motor".
– For the dedicated motor such as the constant-torque motor and low-vibration motor, use the
"inverter-driven, dedicated motor".
– Set Pr. 72 "PWM frequency selection" as indicated below according to the wiring length.
●
Limiting the voltage rise speed of the frequency inverter output voltage (dV/dT):
If the motor requires a rise speed of 500 V/µs or less you must install a filter in the output of the
inverter. Please contact your Mitsubishi dealer for more details.
Wiring Length
50 m 50 m to 100 m 100 m
Parameter 72 15 (14.5 kHz) 8 (8 kHz) 2 (2 kHz)
Tab. 3-27: Setting of Pr. 72 according to the wiring length
NOTE For details of Pr. 72 "PWM frequency selection", refer to section 6.15.