Mitsubishi Electric FR-A720-0.4K Instruction Manual page 35

(3) Total wiring length
The overall wiring length for connection of a single motor or multiple motors should be within the value in the table below.
(The wiring length should be 100m maximum for vector control.)
Pr. 72 PWM frequency selection setting
(carrier frequency)
2 (2kHz) or less
3 to 15 (3kHz to 14.5kHz)
When driving a 400V class motor by the inverter, surge voltages attributable to the wiring constants may occur at the
motor terminals, deteriorating the insulation of the motor.
Refer to page 64 for measures against deteriorated insulation.
CAUTION
· Especially for long-distance wiring, the inverter may be affected by a charging current caused by the stray capacitances of the
wiring, leading to a malfunction of the overcurrent protective function or fast response current limit function or a malfunction or fault
of the equipment connected on the inverter output side. If fast-response current limit function malfunctions, disable this function.
(For Pr. 156 Stall prevention operation selection, refer to page 148 .)
· For details of Pr. 72 PWM frequency selection , refer to page 271.
(4) Cable size of the control circuit power supply (terminal R1/L11, S1/L21)
· Terminal screw size: M4
2
· Cable size: 0.75mm to 2mm
· Tightening torque: 1.5N·m
Total wiring length (1.5K or more)
300m + 300m = 600m
2
Main circuit terminal specifications
0.4K 0.75K
300m 500m
200m 300m
500m or less
300m
300m
1.5K or more
500m
500m
25
2