Total Wiring Length; Cable Size Of The Control Circuit Power Supply - Mitsubishi Electric FR-A800 Installation Manuallines

WIRING

3.3.2 Total wiring length

 With general-purpose motor
Connect one or more general-purpose motors within the total wiring length shown in the following table.
(The wiring length should be 100 m or less under vector control.)
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-A840-01800(55K)
or lower and the sine wave filter (MT-BSL, MT-BSC) to the output side of the FR-A840-02160(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-A842.
 With PM motor
Use the wiring length of 100 m or shorter when connecting a PM motor.
Use one PM motor for one inverter. Multiple PM motors cannot be connected to an inverter.
When the wiring length exceeds 50 m for a 400V class motor driven by an inverter under PM sensorless vector control,
set "9" (6 kHz) or less in Pr. 72 "PWM frequency selection".
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 Instruction Manual.)
For details of Pr. 72 "PWM frequency selection", refer to the Instruction Manual.
The optional surge voltage suppression filter FR-ASF-H and FR-BMF-H can be used under V/F control and Advanced
magnetic flux vector control. The sine wave filter MT-BSL and MT-BSC can be used under V/F control. Do not use the
filters under different control methods.
(For details, refer to the Instruction Manual of the option.)
Refer to the FR-A800 Instruction Manual to drive a 400V class motor by an inverter.
The carrier frequency is limited during PM sensorless vector control. (Refer to the FR-A800 Instruction Manual.)
3.3.3 Cable size of the control circuit power supply (terminal R1/L11, S1/L21)
Terminal screw size: M4
2
Cable size: 0.75mm to 2mm
Tightening torque: 1.5Nm
22
FR-A820-00046(0.4K),
FR-A840-00023(0.4K),
FR-A846-00023(0.4K)
300m
200m
Wiring Length
≤ 50m
50m–100m
≤ 15 (14.5kHz) ≤ 9 (9kHz)
IP55 compatible models: ≤ 6 (6kHz)
2
FR-A820-00077(0.75K),
FR-A840-00038(0.75K),
FR-A846-00038(0.75K)
500m
300m
≥ 100m
≤ 4 (4kHz)
FR-A820-00105(1.5K) or higher
FR-A840-00052(1.5K) or higher,
FR-A842-07700(315K) to
12120(500K)
FR-A846-00052(1.5K) or higher
500m
500m