Technical Specifications

FAQ

1. What is the main function of the Schneider ATS490C17Y soft starter?

The Schneider ATS490C17Y is a high-current Altivar Soft Starter ATS490 designed for controlled starting and stopping of three-phase asynchronous motors. The device uses torque-controlled starting to manage motor acceleration rather than applying the full supply condition immediately. This allows the motor to build up torque progressively, reducing the electrical and mechanical stress normally associated with direct-on-line starting. With a 170 A normal-duty rating and a supply range of 208–690 V AC, the ATS490C17Y is suitable for a wide range of industrial motor applications. It can be used with equipment such as pumps, fans, compressors, conveyors, mixers, and other machines where smooth acceleration, controlled stopping, and reduced mechanical shock are important. The unit also integrates motor protection, communication, internal bypass, diagnostic functions, and Safe Torque Off for more demanding automation systems.

2. What motor power can the ATS490C17Y support?

The applicable motor power depends on the supply voltage, motor connection, operating duty, and actual motor current. The ATS490C17Y has a normal-duty rated operational current of 170 A, and the corresponding motor power increases as the supply voltage increases. Typical application ratings reach approximately 45 kW at 230 V, 90 kW at 400 V, 110 kW at 500 V, and 160 kW at 690 V under normal-duty conditions. For heavy-duty applications, the allowable motor power is lower because the motor may require higher starting torque or longer acceleration. Typical heavy-duty values are approximately 37 kW at 230 V, 75 kW at 400 V, 90 kW at 500 V, and 125 kW at 690 V. Final selection should always be based on motor rated current, load characteristics, starting conditions, duty cycle, and the required application class rather than relying on motor kW alone.

3. What supply voltage does the ATS490C17Y require?

The ATS490C17Y is designed for three-phase AC supplies from 208 V to 690 V at 50–60 Hz. This wide voltage range allows the same soft starter family to be applied to different industrial power systems without changing to a completely different control architecture. The main supply voltage has a specified tolerance of approximately -15% to +10%, while the control supply is 110–230 V AC at 50–60 Hz. Before commissioning, technicians should verify the actual phase-to-phase supply voltage, frequency, phase sequence, grounding arrangement, upstream protection, and motor connection. It is also important to distinguish between the main motor supply and the control supply because an incorrect control voltage can prevent the soft starter from operating even when the main power circuit is correctly connected.

4. How does the ATS490C17Y control motor starting current?

The ATS490C17Y uses controlled semiconductor switching together with torque control to regulate the motor during acceleration. Instead of allowing the motor to draw a large inrush current immediately, the soft starter progressively establishes the required motor torque according to the configured starting parameters. The current-limit setting can be adjusted from approximately 150% to 700% of the rated operational current, with a maximum limit of 5 × Ie. Correct adjustment can reduce the peak demand placed on the electrical supply and help prevent excessive voltage disturbances in installations with limited transformer or generator capacity. At the same time, controlled torque reduces mechanical shock transmitted through couplings, gearboxes, belts, pumps, and other driven machinery. The optimum setting depends on motor characteristics and load torque, so excessively low current limits should be avoided if they prevent the motor from accelerating properly.

5. Which communication protocols are available on the ATS490C17Y?

The ATS490C17Y supports Modbus Serial, Modbus TCP, and EtherNet/IP communication, making it suitable for integration with modern industrial automation systems. Its serial interface uses two-wire RS-485, while Ethernet communication is provided through a 100BASE-TX interface with an RJ45 connector. Modbus Serial transmission rates can be configured between 4.8 and 38.4 kbps, with device addresses ranging from 0 to 247. Through these communication interfaces, a PLC, HMI, SCADA platform, or industrial controller can exchange operating commands, status information, measurements, alarms, and diagnostic information with the soft starter. During commissioning, the communication address, baud rate, network configuration, RS-485 wiring polarity, Ethernet parameters, and PLC control logic should all be checked. Communication problems should be distinguished from actual motor-control faults because the soft starter can continue operating locally even when the supervisory communication network is unavailable.

6. What protection functions does the ATS490C17Y provide?

The ATS490C17Y includes multiple protection functions designed to monitor abnormal electrical and thermal conditions affecting the motor and soft starter. These functions include phase-failure detection, motor overload protection, motor underload monitoring, excessive acceleration-time protection, motor phase-loss detection, phase-reversal detection, and external thermal protection. Motor thermal protection uses a Class 10E characteristic and can help protect the motor when excessive current persists for an extended period. The soft starter can also monitor operating conditions associated with power-stage and motor faults. These integrated functions are useful for improving equipment reliability, but they do not eliminate the need for correctly selected upstream circuit protection, short-circuit protection, grounding, cable protection, and other safety measures. Protection parameters should be configured according to the motor nameplate and actual process requirements.

7. What is the purpose of the internal bypass in the ATS490C17Y?

The internal bypass allows the soft starter to reduce the continuous losses associated with its power semiconductor stage once the motor has completed the controlled starting process. During acceleration, the semiconductor switching devices control the electrical conditions applied to the motor. After the motor reaches stable operating conditions, the internal bypass provides a lower-loss path for normal operation. This reduces heat generation in the power electronics and can improve the thermal efficiency of the overall installation. The bypass is managed by the soft starter’s internal control system and should not be considered a simple substitute for an independently controlled external contactor. Correct power wiring, control configuration, protection settings, and commissioning are necessary to ensure reliable transitions between starting and normal running conditions.

8. How should an ATS490C17Y be troubleshot if the motor does not start correctly?

Troubleshooting should begin with the three-phase main supply and the separate control supply. Confirm that all input phases are present and that the voltage is within the permitted range. Then check the motor wiring, motor connection method, motor rated current, start and stop commands, and any active interlocks. If a phase-failure or phase-loss alarm occurs, inspect the incoming power connections, terminals, contactors, motor cables, and motor winding connections. If an overload or thermal protection fault occurs, investigate the actual motor current, mechanical load, acceleration time, starting frequency, ambient temperature, and cooling conditions. If the motor starts but fails to reach normal speed, the current-limit value may be too restrictive, the acceleration time may be unsuitable, or the driven load may require excessive starting torque. For communication-controlled systems, check Modbus or Ethernet addressing, network connections, communication parameters, PLC commands, and control words. If repeated faults remain after the external electrical, mechanical, and configuration conditions have been verified, the ATS490C17Y and its associated power circuitry should then be inspected for possible hardware problems.