Technical Parameters Parameter Specification Manufacturer ABB Model / Type PR122/P‑LSI Trip Unit Product Category Electronic Overcurrent Protection Module Application Protection for low‑voltage air circuit breakers (3‑phase systems) Poles Protected 3P (Three‑phase protection) Protection Functions • L – Long‑time overload protection • S – Short‑time delayed overcurrent protection • I – Instantaneous short‑circuit protection • G – Ground fault / residual current protection Adjustability Adjustable pickup levels and time settings for L, S, I, G zones Trip Output Drives breaker trip coil to open under defined fault conditions User Interface Typically DIP switches, knobs, or menu settings (depending on model) Indication LEDs or digital indicators for fault status and trip cause Auxiliary / Control Supply AC or DC auxiliary supply voltage depending on breaker/platform (e.g., 110–240 V AC/DC) Frequency 50 / 60 Hz (depending on supply) Mounting Integrated within compatible ACB protection slot Typical Breaker Ratings Supported Commonly used with breakers rated from ~800 A up to ~4000 A (depending on frame size) Standards Compliance Designed to comply with international low‑voltage protection standards Operational Environment Electrical switchgear, distribution panels, industrial power networks