Mitsubishi Electric FR-F820-00077 Instruction Manual page 70

Main circuit terminals
Total wiring length
● With induction motor
Connect one or more induction motors within the total wiring length shown in the following table.
Pr. 72 setting
(carrier frequency)
2 (2 kHz) or lower
3 (3 kHz) or higher
Tab. 2-15:
Fig. 2-24:
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.
Pr. 72 setting
Tab. 2-16:
– For the FR-F820-01160(55K) or lower and the FR-F840-01800(75K) 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.
2 - 42
FR-F820-00046(0.75K)
FR-F840-00023(0.75K)
300 m
200 m
Total wiring length
≤ 500 m
Total wiring length (FR-F820-00105(2.2K) or higher, FR-F840-00052(2.2K) or higher)
50 m
15 (14.5 kHz)
PWM frequency
Installation and wiring
FR-F820-00105(2.2K) or
FR-F820-00077(1.5K)
FR-F840-00038(1.5K) FR-F840-00052(2.2K) or
500 m
300 m
300 m
300 m
300 m + 300 m = 600 m
Wiring length
50 m–100 m
9 (9 kHz)
higher
higher
500 m
500 m
I002368E
100 m
4 (4 kHz)