The ABB PR121/P‑LSIG is an electronic overcurrent protection trip unit designed to be installed in compatible ABB low‑voltage air circuit breakers (ACBs). It provides adjustable and coordinated protection for three‑phase electrical distribution systems by detecting and responding to abnormal current conditions. The unit integrates multiple protection functions for comprehensive fault detection and system safety, including overload, short‑time currents, instantaneous short circuits, and ground faults. The PR121/P‑LSIG is suitable for industrial, commercial, and utility applications where reliable current protection, flexible coordination, and status indication are required.

The Schneider Electric Altistart 48 Soft Starter — ATS48C25Q is an industrial‑grade electronic soft starter designed to provide smooth starting and stopping of three‑phase asynchronous (induction) motors. This soft starter reduces mechanical and electrical stress by controlling the motor’s starting current and torque, improving reliability and extending equipment life. It is suitable for heavy‑duty industrial applications, including pumps, fans, compressors, conveyors, and general machinery. The unit supports torque control and integrates protections for phase loss, thermal conditions, and motor overload.

Category Parameter Specification / Typical Value Application & Configuration Protected Circuit Signal circuits (e.g., 4-20 mA, digital I/O) Circuit Configuration 2-pole (Line-to-Line and Line-to-Ground protection) Connection In-series with the signal line Electrical Characteristics Nominal Voltage 8 - 24 V DC (Typical for signal applications) Max. Continuous Operating Voltage (Uc) ~30 V DC (Please verify in datasheet) Nominal Current (In) Up to 250 mA (Suitable for most signal loops) Voltage Drop < 1.5 V (Low, to minimize impact on the signal) Surge Protection Performance Standards Complies with IEC 61643-21 Nominal Discharge Current (In) 5 kA (8/20 μs waveform) Max. Discharge Current (Imax) 10 kA (8/20 μs waveform) Protection Level (Up) < 40 V (at In, typical for this class) General Data Mounting 35 mm DIN Rail Connection Type Screw terminals Housing Material Plastic (PA 6.6) Operating Temperature -40 °C to +80 °C Status Indication None (This is a basic model without visual fault indicator)