Technical Specifications

FAQ

1. What is the Schneider ATS490C66Y soft starter mainly used for?

The Schneider ATS490C66Y is a high-current soft starter from the Altivar ATS490 series, designed for controlled starting and stopping of large three-phase asynchronous motors. With a rated operational current of 660 A, it is suitable for demanding industrial applications involving large pumps, fans, compressors, conveyors, crushers, mixers, and other heavy-duty machinery. The soft starter uses torque control to gradually establish motor torque during acceleration, reducing the sudden electrical and mechanical stress associated with direct-on-line starting. It also provides motor protection, internal bypass, communication capabilities, monitoring functions, and Safe Torque Off, making it suitable for integration into PLC, HMI, SCADA, and industrial automation systems.

2. What is the rated current of the ATS490C66Y?

The ATS490C66Y has a rated operational current of 660 A under normal-duty conditions and a heavy-duty rated current of 590 A at 40°C. The appropriate rating should be determined from the motor’s actual nameplate current and starting requirements rather than motor power alone. Applications with high starting torque, high inertia, long acceleration periods, or frequent starts may require the heavy-duty rating. If the motor operates continuously above the applicable current rating, the soft starter may activate thermal or overload protection. Engineers should therefore consider motor current, starting current, acceleration time, starting frequency, ambient temperature, and mechanical load when selecting the unit.

3. What motor power range can the ATS490C66Y support?

The applicable motor power depends on supply voltage, duty class, and motor connection. Under normal-duty conditions, the ATS490C66Y can support typical motor ratings of 315 kW at 230 V, 355 kW at 400 V, 400 kW at 440 V, and up to 630 kW at 660 V and 690 V. Under heavy-duty conditions, the ratings are lower, with approximately 315 kW at 400 V, 355 kW at 440 V, and 560 kW at 660 V and 690 V. These values should be used as selection references rather than replacing the motor current rating. For large pumps, compressors, fans, and high-inertia machinery, the starting torque, acceleration time, load characteristics, and operating cycle should also be evaluated to ensure adequate thermal and starting performance.

4. How does the ATS490C66Y control the starting process of a large motor?

The ATS490C66Y uses torque control to regulate motor current and torque during acceleration, allowing the motor to increase speed progressively rather than receiving full starting conditions instantaneously. Compared with direct-on-line starting, controlled acceleration can reduce current peaks, voltage disturbances, and sudden torque changes. This can help protect the electrical distribution system while reducing mechanical stress on shafts, couplings, gearboxes, bearings, belts, and other transmission components. The correct starting parameters depend on the application. For example, pumps may require attention to pressure changes, fans generally have significant inertia, conveyors require sufficient starting torque for the loaded belt, and compressors can have demanding starting characteristics. The starting current should not simply be minimized without considering the torque required by the load.

5. Which communication protocols are supported by the ATS490C66Y?

The ATS490C66Y supports Modbus Serial, Modbus TCP, and EtherNet/IP communication. Its serial interface uses a two-wire RS-485 connection, while the Ethernet interface supports 100BASE-TX. These communication functions allow operating status, measurements, alarms, faults, diagnostic information, and control commands to be exchanged with PLCs, HMIs, SCADA systems, and other industrial controllers. Modbus Serial supports transmission rates from 4.8 to 38.4 kbps, with device addresses ranging from 0 to 247. During commissioning, technicians should verify the device address, baud rate, communication format, RS-485 wiring, Ethernet configuration, and PLC data mapping. If communication is unstable, both the physical network and the control-system configuration should be checked before replacing the soft starter.

6. What protection functions are available on the ATS490C66Y?

The ATS490C66Y provides a range of protection functions for the motor, power supply, and soft starter. These include mains phase failure, motor phase loss, motor thermal protection, motor overload, motor underload, starter thermal protection, excessive acceleration time, phase reversal, external thermal protection, and motor phase-to-earth short-circuit protection. Temperature probe compatibility also allows additional monitoring of motor or equipment temperature. The protection parameters should be configured according to the motor nameplate and the actual process load. Integrated protection should not be regarded as a replacement for upstream short-circuit protection. The complete installation still requires appropriate circuit breakers or fuses, grounding, cable protection, and properly coordinated protective devices.

7. What is the purpose of the internal bypass in the ATS490C66Y?

The internal bypass is used to reduce power semiconductor losses after the motor has completed acceleration and reached stable running conditions. During startup, the soft starter’s power electronics regulate the motor current and torque. After the motor reaches normal operating conditions, the internal bypass provides a lower-loss current path, reducing the continuous heat generated by the semiconductor stage. This is particularly beneficial for large motors that operate for long periods. The bypass is managed by the soft starter’s internal control system and does not eliminate the need for proper upstream protection. During commissioning, the main circuit wiring, starting parameters, acceleration process, and transition to bypass operation should be checked to ensure stable operation without abnormal current, temperature, or fault conditions.

8. How should the ATS490C66Y be troubleshot if the motor fails to start or trips repeatedly?

Begin by checking the three-phase main supply and the 110–230 V AC control supply. Confirm that the supply voltage is within the permitted range and that there is no phase loss or incorrect phase sequence. Then inspect the motor power cables, terminals, motor connection, motor rated-current settings, start/stop commands, and external interlocks. If a phase-loss fault occurs, check the upstream circuit breaker, contactor, fuses, cables, terminals, and motor windings. For overload or thermal protection trips, measure the actual motor current and check the mechanical load, cooling conditions, acceleration time, starting frequency, and ambient temperature. If the motor rotates but cannot reach normal speed, check the available starting torque, current-limit configuration, acceleration time, and load inertia. Large pumps, fans, compressors, and conveyors should also be checked for blockage, excessive friction, or abnormal process loads. If the ATS490C66Y is connected to a PLC through Modbus or Ethernet, verify the communication address, network connection, PLC commands, and data mapping. Reviewing the fault history and diagnostic information before replacing the soft starter can help determine whether the problem originates from the power supply, motor, configuration, communication system, mechanical load, or soft starter itself.