9
WIRING
3.2.2 Total wiring length
The maximum possible length of the motor cables depends on the capacity of the inverter and the selected carrier
frequency. The cables should never be longer than 500m (unshielded).
The lengths in the following table are for unshielded cables. When shielded cables are use divide the values listed in the
table by 2. Note that the values are for the total wiring length – if you connect more than one motor in parallel you must
add the lengths of the individual motor cables.
Note that the motor windings in three-phase AC motors are subject to far more stress when operated via frequency
inverters than with mains operation. The motor must have been approved by the manufacturer for operation on a
frequency inverter.
3.2.3 Cable size of the control circuit power supply (terminal R1/L11, S1/L21)
Terminal Screw Size: M4
Cable size: 0.75mm
2
to 2mm
2
Tightening torque: 1.5N·m
Pr. 72 PWM frequency selection
setting (carrier frequency)
00023
00038
00052 or more
2 (2kHz) or less
300m
500m
500m
3 (3kHz), 4 (4kHz)
200m
300m
500m
5 (5kHz) to 9 (9kHz)
100m
10 (10kHz) or more
50m
Note
For the 01800 or more, the setting range of
Pr. 72 PWM frequency selection
is "0 to 6".
CAUTION
Especially for long-distance wiring (particularly when employing shielded motor cables), 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.
When the fast-response current limit function malfunctions, make the function invalid. (For
Pr.156 Stall prevention operation selection,
refer to the Instruction Manual (applied).
)
For details of
Pr. 72 PWM frequency selection
, refer to
the Instruction Manual (applied)
.