Mitsubishi Electric FR-F802-E Instruction Manual page 33

Main circuit terminals
The line voltage drop can be calculated by the following formula:
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 crimping 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 500 m.
Total wiring length
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 100 m or shorter
6 (6 kHz) or lower
• If the motor capacity is 280 kW or lower, connect the sine wave filter (MT-BSL/BSC) to the output side.
 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.
NOTE
• 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 the fast-response current limit function malfunctions, disable
this function. (For the details of Pr.156 Stall prevention operation selection, refer to the FR-F800 Instruction Manual
(Detailed))
• A sine wave filter (MT-BSL/BSC) can be used under V/F control. Do not use the filters under different control methods.
• For the details of Pr.72 PWM frequency selection, refer to the FR-F800 Instruction Manual (Detailed).
• Refer to page 70
32
INSTALLATION AND WIRING
× wire resistance[mΩ/m] × wiring distance[m] × current[A]
1000
500 m or less
Wiring length longer than 100 m
4 (4 kHz) or lower
to drive a 400 V class motor by an inverter.
300 m
300 m
300 m+300 m=600 m