Inverter-Driven 400V Class Motor - Mitsubishi Electric FR-A720-0.4K Instruction Manual

Inverter-driven 400V class motor

3.4 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:
Measures
It is recommended to take either of the following measures:
(1) Rectifying the motor insulation and limiting the PWM carrier frequency according to the wiring length
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".
3)Set Pr. 72 PWM frequency selection as indicated below according to the wiring length
Pr. 72 PWM frequency selection
(2) Suppressing the surge voltage on the inverter side
Connect the surge voltage suppression filter (FR-ASF-H) to the 55K or less and the sine wave filter (MT-BSL/BSC)
to the 75K or more on the inverter output side.
CAUTION
· For details of Pr. 72 PWM frequency selection , refer to page 271. (When using an option sine wave filter (MT-BSL/BSC) for the 75K
or more, set "25" (2.5kHz) in Pr. 72. )
· For explanation of surge voltage suppression filter (FR-ASF-H) and sine wave filter (MT-BSL/BSC), refer to the manual of each
option.
· Do not perform vector control with a surge voltage suppression filter (FR-ASF-H) or sine wave filer (MT-BSL/BSC) connected.
64
50m or less
15 (14.5kHz) or less
Wiring Length
50m to 100m
9 (9kHz) or less
exceeding 100m
4 (4kHz) or less