Technical Specifications

FAQ

1. What is the main function of the Schneider ATV71HC20N4?
The ATV71HC20N4 is a high-power Altivar 71 variable-speed drive designed for controlling the speed, torque, acceleration, and deceleration of large industrial motors. With a 200 kW / 300 HP rating, it is suitable for demanding machinery where stable motor control and high overload capability are required.

2. What power supply does the ATV71HC20N4 require?
The ATV71HC20N4 operates from a three-phase 380–480 VAC supply at 50–60 Hz. The permitted input voltage tolerance is approximately -15% to +10%. Because the drive handles high current levels, the incoming power cables, circuit protection, disconnect equipment, and upstream transformer or power distribution system must be appropriately rated.

3. What is the rated output current of the ATV71HC20N4?
The rated output current is 387 A at the nominal 2.5 kHz switching frequency. The drive can provide short-term overload current of approximately 580 A for 60 seconds and 638 A for 2 seconds. Actual permissible current depends on operating temperature, switching frequency, load profile, and installation conditions.

4. Which motor control methods are supported by the ATV71HC20N4?
The drive supports V/F control, sensorless flux vector control, and sensor-based flux vector control. These control modes allow the ATV71HC20N4 to be configured for different motor and load characteristics. The appropriate mode should be selected according to the required starting torque, speed accuracy, dynamic response, and motor feedback configuration.

5. Can the switching frequency of the ATV71HC20N4 be adjusted?
Yes. The nominal switching frequency is 2.5 kHz, and the switching frequency can be adjusted within the specified range up to 8 kHz. Increasing the switching frequency can reduce audible motor noise and improve current waveform quality, but it also increases drive losses and may require output-current derating.

6. What should be checked when the ATV71HC20N4 generates an overcurrent fault?
Check the motor cables, motor insulation, grounding, mechanical load, and motor parameters first. Excessive acceleration torque, mechanical blockage, incorrect motor data, short circuits, or unsuitable acceleration settings can cause overcurrent faults. The drive fault history and actual output current should be reviewed before modifying operating parameters.

7. What motor cable length is recommended for the ATV71HC20N4?
The typical maximum cable length is approximately 100 m when shielded motor cable is used and up to 200 m with unshielded cable. For high-power installations, longer cable runs require careful evaluation of EMC, motor insulation stress, grounding, reflected-wave effects, and possible output filtering. The actual permissible configuration should be determined from the complete installation conditions.

8. Can the ATV71HC20N4 be used for applications requiring frequent braking?
Yes. The ATV71HC20N4 can be used with suitable external braking equipment and braking resistors for applications involving rapid deceleration or frequent regenerative energy. For a 200 kW drive, the braking system should be sized according to motor inertia, deceleration time, braking power, duty cycle, and regenerated energy rather than simply selecting a resistor based on motor power.