Mitsubishi Electric 700 Series Installation Manualline page 13

WIRING
3.2.3 Applied cable size
Select the recommended cable size to ensure that a voltage drop will be 2% max.
If the wiring distance is long between the inverter and motor, a main circuit cable voltage drop will cause the motor torque
to decrease especially at the output of a low frequency.
The following table indicates a selection example for the wiring length of 20m.
690V class
Terminal
Applicable Inverter
Screw Size
Type
FR-A770-355K-79 M12(M10)
FR-A770-560K-79 M12(M10)
*1 The recommended cable size is that of the cable (LMFC (heat resistant flexible cross-linked polyethylene insulated cable) etc.) with continuous
maximum permissible temperature of 90°C. Assumes that the surrounding air temperature is 50°Cor less and wiring is performed in an
enclosure.
2
* The terminal screw size indicates the terminal size for R/L1, S/L2, T/L3, U, V, W, PR, PX, P/+, N/–, P1, and a screw for earthing (grounding).
The line voltage drop can be calculated by the following expression:
3 × wire resistance [m /m] × wiring distance [m] x current [A]
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.
CAUTION
Tighten the terminal screw to the specified torque.
A screw that has been tighten too loosely can cause a short circuit or malfunction.
A screw that has been tighten too tightly can cause a short circuit or malfunction due to the unit breakage.
Use crimping terminals with insulation sleeve to wire the power supply and motor.
3.2.4 Maximum permissible motor wiring length
The overall wiring length for connection of a single motor or multiple motors should be within 500m.
(The wiring length should be 100m maximum for vector control.)
When driving a 690V class motor by the inverter, surge voltages attributable to the wiring constants may occur at
the motor terminals, deteriorating the insulation of the motor.
Take the following measure in this case.
Use a "690V class inverter-driven insulation-enhanced motor"
3.2.5 Cable size of the control circuit power supply (terminal R1/L11, S1/L21)
Terminal screw size: M4
Cable size: 0.75mm² to 2mm²
Tightening torque: 1.5Nm
8
Tightening
R/L1,
Torque
S/L2,
[Nm]
*2
T/L3
46 200-12
46 150-12
1000
Crimping Terminal
Earth
U, V, W P/+, P1 (Ground)
Cable
200-12 325-12 150-10
150-12 200-12 200-10
*1
Cable Size (mm²)
R/L1,
S/L2, U, V, W P/+, P1
T/L3
200 200 250
2x150 2x150 2x200
Earth
(Ground)
Cable
150
200