Mitsubishi FR-A800

Main circuit terminals
INSTALLATION AND WIRING
43
2
Total wiring length
 With induction motor
Connect one or more induction motors within the total wiring length shown in the following table. (The wiring length should
be 100 m or shorter under vector control.)
When driving a 400 V 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 measures.
• Use a "400 V class inverter-driven insulation-enhanced motor" and set Pr.72 PWM frequency selection according to
the wiring length.
• For the FR-A840-01800(55K) or lower, connect a surge voltage suppression filter (FR-ASF-H/FR-BMF-H) at the output
side of the inverter. For the FR-A840-02160(75K) or higher, connect a sine wave filter (MT-BSL/BSC) at the output side
of the inverter.
 With PM motor
The wiring length should be 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 400 V class motor driven by an inverter under PM sensorless vector control,
set "9" (6 kHz) or less in Pr.72 PWM frequency selection.
NOTE
• 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. It may also cause a malfunction or fault of the equipment connected ON the inverter output side. If the
fast-response current limit function malfunctions, disable this function. (Refer to Pr.156 Stall prevention operation
selection on page 348.)
• A surge voltage suppression filter (FR-ASF-H/FR-BMF-H) can be used under V/F control and Advanced magnetic flux vector
control. A sine wave filter (MT-BSL/BSC) can be used under V/F control. Do not use the filters under different control
methods.
• For the details of Pr.72 PWM frequency selection, refer to page 277.
• Refer to page 92 to drive a 400 V class motor by an inverter.
• The carrier frequency is limited during PM sensorless vector control. (Refer to page 277.)
Pr.72 setting
(carrier frequency)
FR-A820-00046(0.4K)
FR-A840-00023(0.4K)
FR-A820-00077(0.75K)
FR-A840-00038(0.75K)
FR-A820-00105(1.5K) or higher
FR-A840-00052(1.5K) or higher
2 (2 kHz) or lower 300 m 500 m 500 m
3 (3 kHz) or higher 200 m 300 m 500 m
Total wiring length (FR-A820-00105(1.5K) or higher, FR-A840-00052(1.5K) or higher)
Wiring length 50 m or shorter Wiring length 50 m to 100 m Wiring length longer than 100 m
15 (14.5 kHz) or lower 9 (9 kHz) or lower 4 (4 kHz) or lower
500 m or less
300 m
300 m
300 m+300 m=600 m