Mitsubishi Electric 800 Series Instruction Manual page 51

Line voltage drop [V] =
Use a larger diameter cable when the wiring distance is long or when it is desired to decrease the voltage drop (torque
reduction) in the low speed range.
NOTE
• Tighten the terminal screw to the specified torque.
A screw that has been tightened too loosely can cause a short circuit or malfunction.
A screw that has been tightened too tightly can cause a short circuit or malfunction due to the unit breakage.
• Use crimp terminals with insulation sleeves to wire the power supply and motor.
 Total wiring length
 With induction motor
Connect one or more general-purpose motors within the total wiring length shown in the following table.
Cable type
(carrier frequency)
1 (1 kHz) or lower
Unshielded
2 (2 kHz) or higher
1 (1 kHz) or lower
Shielded
2 (2 kHz) or higher
Total wiring length (FR-E820-0175(3.7K) or higher, FR-E840-0095(3.7K) or higher)
500 m or less
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 measure.
• Use a "400 V class inverter-driven insulation-enhanced motor" and set Pr.72 PWM frequency selection according to the
wiring length.
Wiring length 50 m or
shorter
14.5 kHz or lower
 With PM motor
Use the wiring length of 100 m or shorter when connecting a PM motor.
Use one PM motor for one inverter. Multiple PM motors cannot be connected to an inverter.
When the wiring length exceeds 50 m for a 400 V class motor driven by an inverter under PM sensorless vector control, set "9"
(6 kHz) or less in Pr.72 PWM frequency selection.
50
2. Installation and Wiring
2.5 Main circuit terminals
× wire resistance [mΩ/m] × wiring distance [m] × current [A]
Pr.72 setting Voltage
class
200 V
400 V
200 V
400 V
200 V
400 V
200 V
400 V
Wiring length 50 to 100 m
8 kHz or lower
1000
0.1K 0.2K 0.4K
200 m 200 m 300 m
— — 200 m
30 m 100 m 200 m
— — 30 m
50 m 50 m 75 m
— — 50 m
10 m 25 m 50 m
— — 10 m
300 m
300 m
300 m + 300 m = 600 m
Wiring length longer
than 100 m
2 kHz or lower
0.75K 1.5K 2.2K
500 m 500 m 500 m
200 m 300 m 500 m
300 m 500 m 500 m
100 m 200 m 200 m
100 m 100 m 100 m
50 m 75 m 100 m
75 m 100 m 100 m
25 m 50 m 75 m
3.7K or
higher
500 m
500 m
500 m
500 m
100 m
100 m
100 m
100 m