Technical Specifications

FAQ

1. What is the Schneider ATS490C59Y soft starter designed for?

The Schneider ATS490C59Y is a high-current Altivar ATS490 soft starter designed for controlling the acceleration and deceleration of three-phase asynchronous motors. With a normal-duty rated current of 590 A, it is intended for large industrial motor applications where direct-on-line starting could create excessive current demand and mechanical stress. The device uses torque control to provide a controlled acceleration profile, helping reduce electrical disturbances and mechanical shock. Typical applications include large pumps, fans, compressors, conveyors, mixers, crushers, and other process equipment. The ATS490C59Y also provides integrated motor protection, an internal bypass, communication functions, condition monitoring, cybersecurity functions, and Safe Torque Off, making it suitable for integration into modern industrial automation systems.

2. What is the rated current of the ATS490C59Y?

The ATS490C59Y has a normal-duty rated operational current of 590 A when installed in the motor supply line under the specified conditions. Its heavy-duty rated current is 480 A at 40°C. The correct rating should be selected according to the motor’s actual operating current and starting requirements rather than simply matching the motor’s nominal power. Heavy-duty applications may involve higher starting torque, greater load inertia, longer acceleration times, or demanding starting cycles. In these cases, the 480 A heavy-duty rating should be considered. Motor nameplate current, starting current, acceleration time, starting frequency, ambient temperature, and mechanical load should all be reviewed before final selection.

3. What motor power range can the ATS490C59Y support?

The ATS490C59Y supports different motor power ratings depending on the supply voltage and duty class. Under normal-duty conditions, typical ratings range from 160 kW at 230 V to 560 kW at 660 V and 690 V. At 400 V, the normal-duty motor power rating is 315 kW, while the heavy-duty rating is 250 kW. At 690 V, the normal-duty rating reaches 560 kW and the heavy-duty rating is 500 kW. These ratings should be used together with the motor’s rated current and actual starting characteristics. A motor with a suitable nominal kW value may still require a different soft starter rating if it has high inertia, a long acceleration time, or an unusually high starting torque requirement.

4. How does the ATS490C59Y control motor starting current?

The ATS490C59Y uses torque control to regulate motor acceleration instead of applying full voltage to the motor instantaneously. Its current limitation can be configured from 150% to 700% of In, with a maximum of 5 × Ie. This allows the starting current to be adjusted according to the motor and driven load. Proper current limiting can reduce voltage dips in the electrical network and minimize stress on transformers, generators, cables, and other connected equipment. Controlled torque also helps reduce mechanical shock in shafts, couplings, gearboxes, belts, pumps, and other transmission components. However, the current limit should not be set unnecessarily low. If insufficient current is available to generate the required starting torque, the motor may accelerate too slowly or fail to reach its operating speed.

5. Which communication protocols are available on the ATS490C59Y?

The ATS490C59Y supports Modbus Serial, Modbus TCP, and EtherNet/IP communication. Its serial communication interface uses two-wire RS-485, while the Ethernet interface supports 100BASE-TX. Communication can be used to exchange motor operating status, measured values, alarms, fault information, diagnostic data, and control commands with PLCs, HMIs, SCADA systems, and other industrial automation equipment. Modbus Serial supports transmission rates from 4.8 to 38.4 kbps, with addresses from 0 to 247. The unit also supports optional communication modules for networks such as CANopen, PROFIBUS DP V1, and PROFINET. When commissioning communication, the device address, baud rate, data format, wiring, Ethernet parameters, and PLC configuration should be checked carefully.

6. What protection functions are included in the ATS490C59Y?

The ATS490C59Y includes protection functions for both the motor and soft starter. These include mains phase failure, starter thermal protection, motor thermal protection, motor overload, motor underload, excessive acceleration time, motor phase loss, phase reversal, external thermal protection, inside-delta wiring protection, and protection against short circuits between the motor phase and earth. Motor thermal protection uses a Class 10E characteristic. These functions allow the soft starter to detect abnormal operating conditions and respond according to the configured protection settings. However, the integrated protection does not replace upstream short-circuit protection, circuit breakers, fuses, grounding, or correctly selected motor cables. The protection parameters should be configured according to the motor nameplate and the actual process requirements.

7. What is the purpose of the internal bypass in the ATS490C59Y?

The internal bypass is used to reduce semiconductor losses after the motor has completed its controlled acceleration and reached stable operating conditions. During starting, the ATS490C59Y’s power electronics regulate motor current and torque. Once normal running conditions are established, the internal bypass provides a lower-loss current path, reducing continuous power dissipation in the semiconductor stage. This is especially useful for large motors that operate continuously or for extended periods. The bypass is managed by the soft starter’s internal control system and works together with the motor-control logic. Correct main-circuit wiring and protection are still required. During commissioning, the technician should verify that the motor accelerates normally, reaches stable speed, and transitions correctly into bypass operation without abnormal current, temperature, or fault indications.

8. How should the ATS490C59Y be troubleshot if the motor fails to start or trips repeatedly?

Troubleshooting should begin with the three-phase incoming supply and the 110–230 V AC control supply. Confirm that all phases are present and that the voltage is within the specified range. Next, inspect the motor power cables, terminals, motor connection, motor nameplate settings, start/stop commands, and external interlocks. If a phase-loss fault occurs, check the upstream circuit breaker, contactor, cables, terminals, and motor windings. For overload or thermal faults, check the actual motor current, mechanical load, cooling conditions, acceleration time, starting frequency, and ambient temperature. If the motor rotates but cannot reach normal operating speed, examine the current-limit setting, available starting torque, acceleration time, and load inertia. Pumps, fans, and compressors should also be checked for abnormal process loads. For network-controlled applications, verify Modbus or Ethernet communication parameters, device addressing, PLC commands, and network connectivity. Reviewing the fault history and diagnostic information before replacing the ATS490C59Y can help determine whether the problem originates from the soft starter, motor, power supply, configuration, communication system, or mechanical load.