ABB MMCO Microprocessor Time Overcurrent Relay Bulletin

This document is a descriptive bulletin for the ABB MMCO, a microprocessor-based multiphase instantaneous and time overcurrent relay that simplifies overcurrent protection by incorporating eight time curve families into one programmable unit. It details the relay's features, including fault recording, remote communications via WRELCOM, self-diagnostics, and specifications for current inputs, time dial settings, and environmental ratings.