ABB SACE PR112/P-LSIG Microprocessor Trip Unit

Overview

The SACE PR112/P-LSIG is a microprocessor-based electronic trip unit for the classic ABB SACE Emax old-series air circuit breakers (E1/E2/E3/E4/E6). The suffix LSIG stands for four protection functions: long-time overload, short-time delay, instantaneous short-circuit and earth fault protection. It supports current measurement, fault recording, self-supervision and optional communication. This trip unit is self-powered by the breaker current sensors, and it is widely used on main incoming switchgear, transformer feeders and industrial power distribution skids. This legacy trip unit is obsolete and only available as spare replacement.

Features

The SACE PR112/P-LSIG is designed for SACE Emax old-generation ACBs.PR112/P-LSIG provides complete LSIG four-stage adjustable protection. Self-powered from current transformers; auxiliary supply is optional for display and communication. Built-in metering function for phase current and neutral current monitoring. Fault memory and trip event logging with local indication. Supports zone selective interlocking (ZSI) for selectivity coordination between upstream and downstream breakers. Modular plug-in structure, easy to replace on Emax breaker frames. Compliant with IEC 60947-2, EMC industrial standards.

Specs

Device Type: Electronic Trip Unit Model: SACE PR112/P-LSIG Brand: ABB SACE Series: PR112 for Emax old Protection: L long-time overload, S short-time delay, I instantaneous, G earth fault Power supply: Self-powered by CT; optional auxiliary supply for display / communication Matching breaker: SACE Emax E1, E2, E3, E4, E6 Status: Obsolete legacy spare part

Principle

The SACE PR112/P-LSIG samples current signals from the breaker current transformers. It continuously compares measured values against configured protection thresholds. When overcurrent or earth fault exceeds the setting, it triggers the breaker release mechanism to open the main contacts. It also stores fault data and uploads measurements for local viewing or remote communication.

Applications

The SACE PR112/P-LSIG is fitted on SACE Emax old air circuit breakers for main incoming panels, transformer secondary protection, generator feeders and heavy industrial MCC distribution skids. The SACE PR112/P-LSIG is stocked as spare replacement for legacy ABB Emax low‑voltage switchgear systems.