Technical Specifications

FAQ

1. What is the main function of the Schneider ATS48D38Q soft starter?

The Schneider Electric ATS48D38Q is an Altistart 48 soft starter designed to control the starting and stopping of three-phase asynchronous motors. It regulates motor torque and starting current so that the motor can accelerate progressively instead of experiencing an abrupt starting condition.

The ATS48D38Q is suitable for industrial applications such as pumps, fans, conveyors, compressors and other heavy-duty motor-driven equipment. Compared with direct-on-line starting, controlled starting can reduce electrical disturbances and mechanical shock transmitted to couplings, shafts, gearboxes, belts and other mechanical components.

The soft starter also provides integrated motor thermal protection, starter thermal protection and line phase-failure detection, allowing it to perform both motor starting control and important protection functions within an industrial motor control system.

2. What motor power can the ATS48D38Q handle?

The applicable motor power depends on the supply voltage, motor connection and duty level. For an in-line connection at 230 V, the ATS48D38Q is suitable for approximately 7.5 kW in severe-duty applications and 9 kW in standard-duty applications. At 400 V, the corresponding ratings are approximately 15 kW for severe duty and 18.5 kW for standard duty.

With an inside-delta connection, the applicable ratings are higher. At 230 V, the device can be used for approximately 15 kW severe-duty and 18.5 kW standard-duty applications. At 400 V, the ratings are approximately 22 kW for severe duty and 30 kW for standard duty.

The motor rated current should always be considered together with the motor power. Starting torque, acceleration time, load characteristics and the number of starts per hour should also be evaluated, particularly for heavy-duty applications.

3. What supply voltage and frequency does the ATS48D38Q support?

The ATS48D38Q is designed for three-phase AC supply systems from 230 to 415 V, with a supply voltage tolerance of approximately -15% to +10%. The normal operating frequency is 50–60 Hz.

Before commissioning, the incoming three-phase supply should be checked against the requirements of the motor and soft starter. The supply should be inspected for phase loss, significant voltage imbalance and abnormal voltage conditions.

The ATS48D38Q supports both in-line and inside-delta motor connections. Because these configurations have different electrical characteristics and motor power capabilities, the power circuit must be wired according to the selected connection method.

4. How does the ATS48D38Q control motor starting current?

The ATS48D38Q uses torque-controlled starting to regulate the motor acceleration process. The starting current can be adjusted according to the application, allowing the starting characteristics to be adapted to the motor and connected load.

During direct-on-line starting, an asynchronous motor can draw a high starting current and generate a sudden increase in torque. This can place stress on the electrical supply and mechanical transmission system.

By progressively controlling the starting process, the ATS48D38Q can provide smoother acceleration and reduce abrupt changes in motor torque. This is particularly useful for machinery containing gearboxes, couplings, belts, pumps and other mechanical components that are sensitive to sudden torque changes.

Starting parameters should be adjusted according to the actual load. An acceleration time that is too short may result in insufficient starting torque, while an excessively long acceleration period can increase thermal stress on the motor and soft starter.

5. What protection functions are available on the ATS48D38Q?

The ATS48D38Q provides integrated motor thermal protection, starter thermal protection and line phase-failure detection.

Motor thermal protection helps monitor the thermal load generated during starting and normal operation. Long acceleration times, motor overloads or frequent starts can cause heat to accumulate, making thermal protection important for reliable motor operation.

Starter thermal protection protects the internal power electronics from excessive thermal stress. Frequent starting, heavy loads or extended acceleration periods can increase the temperature of the power components.

Line phase-failure detection helps identify problems in the three-phase power supply. A missing phase can cause current imbalance, reduced motor torque and excessive heating. When a phase-related fault occurs, the incoming power supply and motor wiring should be checked carefully.

6. Can the ATS48D38Q communicate with a PLC through Modbus?

Yes. The ATS48D38Q supports Modbus communication through an RS485 multidrop interface. It can therefore be integrated with PLCs, industrial controllers and other automation equipment.

The communication interface uses an RJ45 connector and supports transmission speeds of 4800, 9600 and 19200 bps. This allows the soft starter to exchange available operating status and diagnostic information with an automation control system.

During commissioning, the Modbus address, baud rate and other relevant communication parameters must be configured consistently between the ATS48D38Q and the PLC or Modbus master.

If communication fails, the troubleshooting process should begin with the communication parameters, RS485 wiring, connector and PLC configuration. A communication failure does not necessarily mean that the power section of the soft starter is defective.

7. Why might the ATS48D38Q trip during motor starting?

A startup trip can have several possible causes, including incorrect motor parameters, unsuitable starting settings, abnormal power supply conditions, incorrect motor wiring, excessive mechanical load or thermal stress.

The first step is to identify the actual fault or diagnostic condition. The motor rated current should then be compared with the ATS48D38Q rating, followed by a check of the starting torque, acceleration time and other relevant parameters.

The three-phase supply should be inspected for phase loss, abnormal voltage or excessive imbalance. The motor terminals should also be checked to ensure that the selected in-line or inside-delta connection has been wired correctly.

Mechanical problems should not be overlooked. A blocked pump, overloaded conveyor, excessive compressor pressure, seized bearing or other mechanical restriction can prevent the motor from reaching normal operating speed.

For machines with frequent starts, the interval between successive starts should also be evaluated. Repeated starting without sufficient cooling time can cause thermal accumulation and eventually activate the soft starter’s thermal protection.

8. What should be considered when selecting and commissioning the ATS48D38Q?

Selection should begin with the motor rated current and supply voltage, followed by an evaluation of the actual application duty. Motor power, connection method, starting torque, acceleration time, starting frequency and load characteristics should all be considered.

The connection method is particularly important. At 400 V, an in-line configuration is suitable for approximately 15 kW severe-duty and 18.5 kW standard-duty applications, while an inside-delta configuration can accommodate approximately 22 kW severe-duty and 30 kW standard-duty applications.

During commissioning, the motor parameters should be configured correctly and the starting torque, acceleration time and protection settings should be adjusted according to the actual mechanical load.

The power and control wiring should be inspected before energizing the system. If PLC control or Modbus communication is used, the digital inputs, outputs and communication link should also be tested.

After initial startup, monitoring motor current, acceleration behavior, operating status and fault records can help confirm that the ATS48D38Q is correctly configured for the actual machine.