1.2.12 Inverter-driven 400V class motor
In the PWM type inverter, a surge voltage attributable to wiring constants is generated
at the motor terminals. Especially for a 400V class motor, the surge voltage may
deteriorate the insulation. When the 400V class motor is driven by the inverter,
consider the following measures:
It is recommended to take either of the following measures:
(1) Rectifying the motor insulation
For the 400V class motor, use an insulation-enhanced motor. Specifically
1) Specify the "400V class inverter-driven, insulation-enhanced motor".
2) For the dedicated motor such as the constant-torque motor and low-vibration
motor, use the "inverter-driven, dedicated motor".
When the wiring length between the motor and inverter is 40m or more, take
the above countermeasure and also set the long wiring mode in Pr. 70 "Soft-
PWM setting". (Refer to page 113 for Pr. 70.)
(2) Suppressing the surge voltage on the inverter side
On the secondary side of the inverter, connect the optional surge voltage
suppression filter (FR-ASF-H).
Main circuit terminals