Technical Specifications

FAQ

1. What is the main function of the Schneider Electric ATS48C17Q soft starter?

The ATS48C17Q is an Altistart 48 soft starter designed to control the starting and stopping of three-phase asynchronous motors. It uses torque-controlled starting to gradually accelerate the motor rather than applying full supply voltage directly at startup. This approach helps reduce starting current and mechanical shock transmitted to the driven equipment. The ATS48C17Q is particularly suitable for demanding applications such as industrial pumps, ventilation systems, compressors, conveyors, and other high-inertia machinery. It also provides integrated motor and starter thermal protection, helping monitor operating conditions and reduce the risk of damage caused by excessive thermal loading.

2. What motor power range is suitable for the ATS48C17Q?

The ATS48C17Q is designed for motors in the approximately 37–132 kW range, although the actual applicable motor power depends on the supply voltage, motor connection method, and whether the application is standard duty or heavy duty. With line connection at 400 V, the unit can support approximately 90 kW for standard applications and 75 kW for heavy-duty applications. When connected to the motor delta terminals, the applicable rating can reach approximately 132 kW for standard applications and 110 kW for heavy-duty applications. At 230 V, the corresponding ratings are lower. Selection should always be based on the motor rated current and actual starting duty, not simply the motor’s nominal kW rating.

3. What supply voltage does the ATS48C17Q support?

The ATS48C17Q is designed for a three-phase supply voltage of 230–415 VAC, with a permitted voltage range of approximately 195–456 VAC. The normal supply frequency is 50–60 Hz, with an allowable frequency range of approximately 47.5–63 Hz. Before commissioning, the incoming voltage should be measured and compared with the soft starter and motor nameplate requirements. The motor connection method must also be correctly selected for the actual supply voltage. Incorrect voltage or connection configuration may lead to insufficient starting torque, excessive current, overheating, or protective trips.

4. How does torque-controlled starting improve motor performance?

The ATS48C17Q uses torque control rather than relying solely on a conventional voltage ramp. During acceleration, the starter controls the motor torque and limits starting current to approximately five times the motor rated current. This provides smoother acceleration and can significantly reduce mechanical shock on couplings, gearboxes, belts, pumps, and other transmission components. Torque-controlled starting is particularly useful for high-inertia loads or machines that require controlled acceleration. For pumping applications, it can also help provide a smoother transition during startup and stopping. The actual parameters should be adjusted according to the motor characteristics and the mechanical load to ensure reliable acceleration without unnecessarily extending the starting period.

5. What should be checked if a motor connected to the ATS48C17Q fails to accelerate properly?

First, check the three-phase supply and confirm that all phases are present and within the permitted voltage range. Next, verify the motor wiring, motor connection method, rated current setting, and control input signals. If the motor is connected through its delta terminals, the connection must be correctly configured according to the application. If the electrical installation is correct, inspect the mechanical load for excessive friction, blocked pumps, seized bearings, conveyor obstruction, or other conditions requiring unusually high starting torque. The current limitation should also be checked. If the current limit is too low for the load, the motor may not develop sufficient torque to reach normal operating speed. A very long acceleration time can also indicate that the motor is struggling with the mechanical load.

6. Why might the ATS48C17Q trip during motor starting?

A trip during starting can be caused by several conditions, including phase loss, abnormal supply voltage, excessive motor current, incorrect motor parameters, excessive mechanical load, prolonged acceleration, incorrect motor wiring, or unsuitable current-limiting settings. When a fault occurs, the diagnostic condition should be identified before attempting another start. Repeatedly resetting the starter without determining the cause can increase thermal stress on the motor and starter. The motor nameplate current should be compared with the configured parameters, while the three-phase supply and motor connections should be inspected carefully. If the mechanical load has high inertia or requires high starting torque, the starting configuration should be reviewed to ensure that the starter can accelerate the load within the expected time.

7. How should the motor thermal protection of the ATS48C17Q be configured?

The motor rated-current parameter should be set according to the actual value specified on the motor nameplate and should take the motor connection method into account. This parameter is an important reference for the ATS48C17Q’s integrated thermal motor protection. If the configured current is too high, an actual motor overload may not be detected appropriately. If it is set too low, nuisance trips may occur during normal operation or startup. The motor’s duty cycle, cooling conditions, ambient temperature, starting frequency, and actual load should also be considered. For heavy-duty applications involving frequent starts or long acceleration periods, thermal conditions should be evaluated carefully rather than relying solely on the nominal motor power.

8. What should be checked before installing or replacing an ATS48C17Q?

Before installation or replacement, verify the motor rated voltage, rated current, power, frequency, phase configuration, connection method, and mechanical load characteristics. Confirm that the three-phase supply is within the ATS48C17Q’s permitted voltage and frequency range and determine whether the application requires standard-duty or heavy-duty operation. The main power circuit, control wiring, grounding, protective devices, and motor insulation should be checked before energizing the system. The soft starter should be installed vertically with sufficient ventilation for its forced-convection cooling system. After wiring, verify the motor current settings, starting parameters, current limitation, control inputs, and protection functions. During commissioning, perform controlled start tests while monitoring motor current, acceleration, fault conditions, and temperature. For high-inertia or frequently started machinery, the complete duty cycle should be evaluated to prevent excessive thermal stress and ensure reliable long-term operation.