Mitsubishi Electric FR-F800, Instruction Manual, Page: 66 / 834

Main circuit terminals Installation and wiring
2 - 38
Total wiring length
●
With induction motor
Connect one or more induction motors within the total wiring length shown in the following table.
When driving a 400 V class motor by the inverter, surge voltages attributable to the wiring constants
may occur at the motor terminals, deteriorating the insulation of the motor. In this case, take one of
the following measures.
– Use a "400 V class inverter-driven insulation-enhanced motor" and set Pr. 72 "PWM frequency
selection" according to the wiring length.
– For the FR-F820-01160(55K) or lower and the FR-F840-01800(755K) or lower, connect a surge
voltage suppression filter (FR-ASF-H/FR-BMF-H) at the output side of the inverter. For the FR-F840-
01800(75K) or higher, connect a sine wave filter (MT-BSL/BSC) at the output side of the inverter.
Pr. 72 setting
(carrier frequency)
FR-F820-00046(0.75K)
FR-F840-00023(0.75K) FR-F820-00077(1.5K)
FR-F840-00038(1.5K)
FR-F820-00105(2.2K) or
higher
FR-F840-00052(2.2K) or
higher
2 (2 kHz) or lower 300 m 500 m 500 m
3 (3 kHz) or higher 200 m 300 m 500 m
Tab. 2-15: Total wiring length
I002368E
Fig. 2-22: Total wiring length (FR-F820-00105(2.2K) or higher, FR-F840-00052(2.2K) or higher)
Wiring length
50 m 50 m–100 m 100 m
Pr. 72 setting 15 (14.5 kHz) 9 (9 kHz) 4 (4 kHz)
Tab. 2-16: PWM frequency
≤
500 m
300 m
300 m
300 m + 300 m = 600 m