Schneider ATS48C48Q Soft Starter Unit

Module Feature

ATS48C48Q is Schneider Altistart 48 series torque-controlled soft starter for three-phase asynchronous motors.

It adopts six thyristor power regulation architecture, supports torque ramp control instead of simple voltage ramp, which effectively reduces water hammer for pump load and mechanical shock for fan and conveyor. It integrates motor thermal overload protection, phase loss, overcurrent and thyristor short-circuit fault detection. It has built-in Modbus-RTU communication interface for remote parameter viewing and fault uploading to PLC/DCS. It can be matched with external bypass contactor to reduce heat loss during continuous running. This model is discontinued and is stocked as critical maintenance spare for water treatment, metallurgy and power plant motor control cabinet.

Working principle

The internal CPU collects motor current and voltage sampling signals.

It adjusts the firing angle of thyristors to control output voltage and torque during start and stop process, realizing smooth acceleration and deceleration without impact current. When fault condition is detected, it immediately blocks thyristor trigger pulse and outputs trip signal to cut off motor loop. Operation data, fault code and thermal state are stored in memory and uploaded via Modbus bus.

Onboard components

Three-phase thyristor module, current sampling transformer, main control CPU, LCD local display, operation keypad, Modbus communication circuit, fault relay output, heat sink cooling fan, status LED array and metal housing.

LED indicators

Front LEDs indicate power supply, run status, bypass engaged, overload warning, phase fault and hardware alarm.

Hardware self‑diagnosis

Built-in supervision detects phase imbalance, phase loss, overcurrent, motor thermal overload, heatsink overheat and thyristor failure. Fault information can be read by SoMove configuration software.

Programming software

SoMove, used for starting curve setting, protection threshold, communication address and fault log reading.

Electrical & Process Parameters

Model:ATS48C48Q Brand:Schneider Electric Device type:Altistart48 torque soft starter Function:Smooth start/stop and multi-protection for large asynchronous motors of pump, fan and compressor

Mechanical & Structure

Mounting:Panel rack mounting Protection class:IP20 Housing:Reinforced plastic industrial soft starter housing with cooling heat sink

Environmental

Operating temperature:-10℃ ~ +40℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE, IEC 60947 Status:Original Schneider legacy soft starter spare

Installation

Isolate main power before replacement.

Check three-phase wiring sequence, install external bypass contactor as required, set motor rated current and starting mode, test start response and protection trip function.

Interface

Three-phase main power terminal, motor output terminal, control DI/DO screw terminal, Modbus communication port, local HMI panel.

Diagnostic

Overcurrent alarm: Motor locked rotor, short circuit or starting time too long. Phase loss fault: Input power missing, fuse blown or loose terminal. Communication lost: Modbus address conflict, cable damage or bus termination error.

Product Brief

Schneider ATS48C48Q soft starter, Altistart 48 torque control spare for pump, fan and compressor asynchronous motor cabinet replacement.