6
WIRING
3.3 Cables and wiring length
3.3.1 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.
400V class (when input power supply is 440V)
Selection example for the wiring length of 20m
The line voltage drop can be calculated by the following expression:
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.
Applicable Inverter Type
Terminal Screw Size
*
1
Tightening Torque
[Nm]
Crimping Terminal
R/L1, S/L2, T/L3, P1, +
U, V, W
FR-A741-5.5K
M4
1.5
2-4
2-4
FR-A741-7.5K
M4
1.5
5.5-4
5.5-4
FR-A741-11K
M5
2.5
5.5-5
5.5-5
FR-A741-15K
M5
2.5
8-5
8-5
FR-A741-18.5K
M6
4.4
14-6
8-6
FR-A741-22K
M6
4.4
14-6
14-6
FR-A741-30K
M6
4.4
22-6
22-6
FR-A741-37K
M8
7.8
22-8
22-8
FR-A741-45K
M8
7.8
38-8
38-8
FR-A741-55K
M8
7.8
60-8
60-8
*
1
The terminal screw size indicates the terminal size for R/L1, S/L2, T/L3, U, V, W, and a screw for earthing (grounding).
Applicable Inverter Type
Cable Sizes
HIV [mm
2
] *
1
AWG ([mm
2
]) *
2
PVC
[mm
2
] *
3
R/L1, S/L2,
T/L3, P1, +
U, V, W
Earth
Cable
R/L1, S/L2,
T/L3, P1, +
U, V, W
R/L1, S/L2,
T/L3, P1, +
U, V, W
Earth
Cable
FR-A741-5.5K
2
2
3.5
12 (3.3)
14 (2.1)
2.5
2.5
4
FR-A741-7.5K
3.5
3.5
3.5
12 (3.3)
12 (3.3)
4
4
4
FR-A741-11K
5.5
5.5
8
10 (5.3)
10 (5.3)
6
6
10
FR-A741-15K
8
8
8
8 (8.4)
8 (8.4)
10
10
10
FR-A741-18.5K
14
8
14
6 (13.3)
8 (8.4)
16
10
16
FR-A741-22K
14
14
14
6 (13.3)
6 (13.3)
16
16
16
FR-A741-30K
22
22
14
4 (21.1)
4 (21.1)
25
25
16
FR-A741-37K
22
22
14
4 (21.1)
4 (21.1)
25
25
16
FR-A741-45K
38
38
22
1 (42.4)
2 (33.6)
50
50
25
FR-A741-55K
60
60
22
1/0 (42.4/53.4)
50
50
25
*
1
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.
*
2
For the 45K or less, the recommended cable size is that of the cable (THHW cable) with continuous maximum permissible temperature of
75°C. Assumes that the surrounding air temperature is 40°C or less and the wiring distance is 20m or less.
For the 55K, the recommended cable size is that of the cable (THHN cable) with continuous maximum permissible temperature of 90°C. Assu-
mes that the surrounding air temperature is 40°C or less and wiring is performed in an enclosure. (Selection example for use mainly in the Uni-
ted States (AWG = American Wire Gauge). The values in parentheses indicate the cable sizes in mm².)
*
3
For the 45K or less, the recommended cable size is that of the cable (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.
For the 55K, the recommended cable size is that of the cable (XLPE cable) with continuous maximum permissible temperature of 90°C. Assu-
mes that the ambient temperature is 40°C or less and wiring is performed in an enclosure. (Selection example for use mainly in Europe.)
NOTE
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
wire resistance [ m
Ω
/
m
]
wiring distance [m]
current [A]
×
×
×
1000
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