10
Main circuit terminals
Total wiring length
The overall wiring length for connection of a motor should be within the value in the table below.
(An explosion-proof test is not performed for the multiple motor connection.)
FR-B series
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. Take the following measures in this case.
• Use a "400 V class inverter-driven insulation-enhanced motor" and set frequency in
Pr. 72 PWM frequency selection
according to wiring length. (This
setting is only available with FR-B series.)
FR-B3 series
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. If the fast-response current limit function malfunctions,
disable this function. (
Pr.156 Stall prevention operation selection
Refer to Chapter 5 of the FR-A800 Instruction Manual (Detailed).)
• For details of
Pr.72 PWM frequency selection
, refer to Chapter 5 of the FR-A800 Instruction Manual (Detailed).
Cable size for the control circuit power supply (terminals R1/L11 and S1/L21)
• Terminal screw size: M4
• Cable gauge: 0.75 to 2 mm
2
• Tightening torque: 1.5 N
•
m
Pr.72 PWM frequency selection setting
(carrier frequency)
FR-B-750
FR-B-1500 or higher
2 (2 kHz) or lower
500 m
500 m
3 (3 kHz) or higher
300 m
500 m
Wiring length
50 m or shorter
50 m to 100 m
Longer than 100 m
PWM carrier frequency
14.5 kHz or lower
9 kHz or lower
4 kHz or lower
Inverter type
400
750
1500 or higher
FR-B3 (standard)
300 m
500 m
500 m
FR-B3-N (low noise)
200 m
300 m
500 m
