Mitsubishi Electric FR-D720S SC EC, Instruction Manual

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Main circuit connection Wiring
3 - 8
Cables and wiring length
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 tables indicate a selection example for the wiring length of 20m.
200V class (when input power supply is 220V)
400V class (when input power supply is 440V)
The recommended cable size is that of the HIV cable (600V class 2 vinyl-insulated cable)
with continuous maximum permissible temperature of 75°C. Assumes that the ambient
temperature is 50°C or less and the wiring distance is 20m or less.
The recommended cable size is that of the THHW cable with continuous maximum
permissible temperature of 75°C. Assumes that the ambient temperature is 40°C or less
and the wiring distance is 20m or less.
(Selection example for use mainly in the United States.)
The recommended cable size is that of the PVC cable with continuous maximum permissible
temperature of 70°C. Assumes that the ambient temperature is 40°C or less and the wiring
distance is 20m or less.
(Selection example for use mainly in Europe.)
The terminal screw size indicates the terminal size for R/L1, S/L2, T/L3, U, V, W, PR, P/+,
N/–, P1 and a screw for earthing. (For single-phase power input, the terminal screw size
indicates the size of terminal screw for L1, N, U, V, W, PR, +, – and P1 and a screw for
earthing (grounding).)
The line voltage drop can be calculated by the following expression:
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.
Applicable Inverter
Type
Terminal
Screw
Size
Tighten-
ing
Torque
[Nm]
Crimping
Terminal
Cable Size
HIV etc. [mm²] AWG PVC [mm²]
L1, N,
P1, +
U, V, W
L1, N,
P1, +
U, V, W
Earth
Cable
Gauge
L1, N,
P1, +
U, V, W
L1, N,
P1, +
U, V, W
Earth
Cable
Gauge
FR-D720S-008SC to
042SC
M3,5 1,2 2-3,5 2-3,5 2 2 2 14 14 2,5 2,5 2,5
FR-D720S-070SC M4 1,5 2-4 2-4 2 2 2 14 14 2,5 2,5 2,5
FR-D720S-100SC M4 1,5 5,5-4 2-4 3,5 2 3,5 12 14 4 2,5 4
Tab. 3-5: Cable size
Applicable Inverter
Type
Terminal
Screw
Size
Tighten-
ing
Torque
[Nm]
Crimping
Terminal
Cable Size
HIV etc. [mm²] AWG PVC [mm²]
L1, L2,
L3, P1,
P/+
U, V, W
L1, L2,
L3, P1,
P/+
U, V, W
Earth
Cable
Gauge
L1, L2,
L3, P1,
P/+
U, V, W
L1, L2,
L3, P1,
P/+
U, V, W
Earth
Cable
Gauge
FR-D740-012SC to
080SC
M4 1,5 2-4 2-4 2 2 2 14 14 2,5 2,5 2,5
FR-D740-120SC M4 1,5 5,5-4 2-4 3,5 2 3,5 12 14 4 2,5 4
FR-D740-160SC M4 1,5 5,5-4 5,5-4 3,5 3,5 3,5 12 12 4 4 4
Tab. 3-6: Cable size
Line voltage drop [V]
3 wire resistance [m
Ω
/m
] ×
wiring distance [m]
×
current [A]
×
1000
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