Mitsubishi Electric 800 Series Assembly & Installation Manuallines page 18

WIRING
2.3.2 Total wiring length
With general-purpose motor
Connect one or more general-purpose motors within the total wiring length 500 m.
(The wiring length should be 100 m or less under vector control.)
Total wiring length
When driving a 690 V class motor by the inverter, surge voltages attributable to the wiring constants may occur at the motor ter-
minals, deteriorating the insulation of the motor. In this case, use a 690 V class inverter-driven insulation-enhanced motor. When
the wiring length exceeds 100 m, set "4" (4 kHz) or less in Pr. 72 „PWM frequency selection (carrier frequency)".
CAUTION
Especially for long-distance wiring, the inverter may be affected by a charging current caused by stray capacitances of the
wiring, leading to an activation of the overcurrent protection, malfunction of the fast-response current limit operation, or even
to an inverter failure. It may also cause 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 Pr. 156 "Stall prevention operation selection", refer to the FR-A870 Instruction Manual (Function).)
For details of Pr. 72 "PWM frequency selection", refer to the FR-A870 Instruction Manual (Function).
Refer to the FR-A870 Instruction Manual (Hardware) to drive a 690 V class motor by an inverter.
2.3.3 Cable size of the control circuit power supply (terminal R1/L11, S1/L21)
Terminal screw size: M4
Cable gauge: 0.75 mm² to 2 mm²
Tightening torque: 1.5 Nm
12
500 m or less
300 m
300 m
300 m + 300 m = 600 m