Technical Specifications

FAQ

1. What is the main function of the Schneider Electric ATS48C11Q soft starter?

The ATS48C11Q is an Altistart 48 soft starter designed to control the starting and stopping of three-phase asynchronous motors. Instead of applying full voltage to the motor immediately, it uses torque control to provide a controlled acceleration profile. This reduces mechanical shock in the driven equipment and helps limit excessive starting current. The unit is particularly suitable for industrial applications where smooth motor acceleration and deceleration are important, including pumps, fans, compressors, conveyors and process machinery. The ATS48 platform also integrates motor and machine protection functions, allowing the soft starter to perform more than simple motor starting.

2. What motor rating is suitable for the ATS48C11Q?

The ATS48C11Q has a 100 A starter rating and is intended for motor applications in the approximate 22–90 kW range, depending on the supply voltage and the required duty. The exact motor selection should not be based on kW alone. The motor’s rated current, supply voltage, starting characteristics, load type, starting frequency and operating conditions must also be considered. For applications with high inertia, frequent starting, long acceleration times or severe mechanical loads, the appropriate ATS48 rating should be selected based on the actual thermal and starting requirements rather than simply matching the motor’s nominal power.

3. What supply voltage does the ATS48C11Q support?

The ATS48C11Q is designed for three-phase AC supply voltages from 230 to 415 V, with a specified supply tolerance of approximately -15% to +10%. The normal operating frequency is 50–60 Hz. Before commissioning, the incoming line voltage should be measured and checked against the motor nameplate and soft starter requirements. The motor connection must also correspond to the selected supply voltage. Incorrect voltage selection or improper motor connection can result in insufficient starting torque, excessive current, overheating or motor damage.

4. How does the torque control function of the ATS48C11Q improve motor starting?

The ATS48 uses Schneider Electric’s Torque Control System to regulate the motor’s starting and stopping behavior. Rather than relying only on a simple voltage ramp, torque control adjusts the starting process according to the motor and load conditions. This can produce smoother acceleration and reduce mechanical stress on couplings, gearboxes, belts, pumps and other driven components. It is particularly useful for applications where a conventional voltage-ramp starter may provide inconsistent acceleration. The correct settings should be established during commissioning based on the motor characteristics and the actual mechanical load.

5. What should be checked if the motor fails to accelerate with an ATS48C11Q?

Start by checking the three-phase input voltage and confirming that all phases are present and within the specified range. Next verify the motor wiring, motor nameplate current, connection configuration and control inputs. The motor’s rated current parameter should be correctly configured in the soft starter because this value is used by the motor thermal protection and other control functions. If the electrical system is correct, inspect the mechanical load for excessive friction, blockage or unusually high starting torque requirements. The current-limiting setting should also be checked. If current limitation is set too low for the application, the motor may not develop enough torque to accelerate the load to operating speed.

6. Why might the ATS48C11Q trip during motor starting?

A trip during starting can be caused by excessive motor current, an incorrectly configured motor rated-current value, prolonged acceleration, excessive mechanical load, phase loss, incorrect motor wiring or unsuitable current-limiting settings. The first step is to identify the displayed fault or diagnostic condition rather than repeatedly restarting the motor. Check the motor nameplate data against the parameters configured in the ATS48C11Q. Then inspect the motor and driven equipment for mechanical problems. If the motor requires a high starting torque, the current limitation and starting configuration may need to be adjusted within the permitted operating range. Repeated trips without identifying the underlying cause can increase thermal stress on both the motor and starter.

7. How should the motor thermal protection be configured on the ATS48C11Q?

The motor rated current should be entered according to the value shown on the motor nameplate and the actual motor connection. This parameter is important because the ATS48 uses it as a reference for motor thermal protection. The configured value should not simply be copied from a generic motor table when the actual nameplate is available. The motor’s installation conditions, cooling method, duty cycle and application load should also be considered. If the configured current is too high, the protection may not respond appropriately to an overloaded motor. If it is too low, nuisance trips may occur during normal operation or starting. Correct parameterization should therefore be performed during commissioning by qualified personnel.

8. What should be checked before installing or replacing an ATS48C11Q?

Before installation or replacement, verify the motor rated voltage, rated current, power, frequency, phase configuration and application duty. Confirm that the ATS48C11Q is suitable for the actual motor and that the incoming three-phase supply is within the permitted voltage range. Inspect the main power circuit, control wiring, grounding, protective devices and motor insulation before energizing the system. The soft starter should be mounted vertically with appropriate ventilation and clearance around the unit. During commissioning, verify the motor current setting, starting and stopping parameters, current limitation and protection functions. Perform controlled test starts while monitoring motor current, acceleration, fault status and temperature. If the unit is being used in a demanding application, the starting duty and thermal requirements should be evaluated carefully to prevent repeated overload or overheating conditions.