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3
PRECAUTIONS FOR USE OF THE INVERTER
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
(2) Suppressing the surge voltage on the inverter side
Connect the surge voltage suppression filter (FR-ASF-H/FR-BMF-H) on the inverter output side.
Wiring Length
50m (164.04feet) or less
50m to 100m
(164.04feet to 328.09feet)
exceeding 100m
(328.09feet)
Pr. 72 PWM frequency selection 15 (14.5kHz) or less 8 (8kHz) or less 2 (2kHz) or less
NOTE
For details of Pr. 72 PWM frequency selection, refer to page 148.
For explanation of surge voltage suppression filter (FR-ASF-H/FR-BMF-H), refer to the manual of each option