Mitsubishi Electric FR-F840-00023 Installation Manuallines page 24

WIRING
2.3.2 Total wiring length
With general-purpose motor
Connect one or more general-purpose motors within the total wiring length shown in the following table.
Pr. 72 setting
(carrier frequency)
2 (2kHz) or lower
3 (3kHz) or higher
When driving a 400V class motor by the inverter, surge voltages attributable to the wiring constants may occur at the
motor terminals, deteriorating the insulation of the motor. In this case, take one of the following measure.
– Use a "400V class inverter-driven insulation-enhanced motor" and set frequency in Pr. 72 "PWM frequency selection"
according to wiring length.
Pr. 72 setting
– Connect the surge voltage suppression filter (FR-ASF-H, FR-BMF-H) to the output side of the FR-F840-01160(55K) or
lower and the sine wave filter (MT-BSL, MT-BSC) to the output side of the FR-F840-01800(75K) or higher.
– If the motor capacity is 280 kW or lower, connect the sine wave filter (MT-BSL/MT-BSC) to the output side of the
FR-F842.
With PM motor
Use the following wiring length or shorter when connecting a PM motor.
Voltage class
200V
400V
FR-F842: Use the wiring length of 100m or shorter when connecting a PM motor.
Use one PM motor for one inverter. Multiple PM motors cannot be connected to an inverter.
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. If the fast-response current limit function malfunctions, disable this function.
(For Pr. 156 "Stall prevention operation selection", refer to the FR-F800 Instruction Manual.)
The optional surge voltage suppression filter (FR-ASF-H/FR-BMF-H) or sine wave filter (MT-BSL/MT-BSC) cannot be
used under PM motor control. Do not connect it.
For details of Pr. 72 "PWM frequency selection", refer to the FR-F800 Instruction Manual.
The FR-ASF-H and FR-BMF-H can be used under V/F control and Advanced magnetic flux vector control. The MT-BSL
and MT-BSC can be used under V/F control.
(For details, refer to the Instruction Manual of the option.)
Refer to the FR-F800 Instruction Manual to drive a 400V 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 size: 0.75mm² to 2mm²
Tightening torque: 1.5Nm
18
FR-F820-00046(0.75K),
FR-F840-00023(0.75K)
300m
200m
Wiring Length
≤ 50m 50m–100m
≤ 15 (14.5kHz) ≤ 9 (9kHz)
FR-F842: ≤ 6 (6kHz)
Pr. 72 setting
(carrier frequency)
0 (2kHz) to 15 (14kHz)
≤ 5 (2kHz)
6 to 9 (6kHz)
≥ 10 (10kHz)
FR-F820-00077(1.5K),
FR-F840-00038(1.5K)
500m
300m
≥ 100m
≤ 4 (4kHz)
FR-F820-00077(1.5K) or lower,
FR-F840-00038(1.5K) or lower
100m
100m
50m
50m
FR-F820-00105(2.2K) or higher,
FR-F840-00052(2.2K) or higher,
FR-F842
500m
500m
FR-F820-00105(2.2K) or higher,
FR-F840-00052(2.2K) or higher
100m
100m
100m
50m