Schneider Electric MA11128 Undervoltage Trip Unit

The Schneider Electric MA11128 Undervoltage Trip Unit is a 48V DC undervoltage release accessory designed to be installed inside Square D molded‑case circuit breakers. When the UV release’s control voltage falls below its setpoint, it provides an instantaneous trip signal to open the breaker, delivering automatic protection during undervoltage conditions. Compatible with MA, MAF, MAL, MAP, MH, MHF, MHL, and MHP frame breakers, the unit is intended for internal installation inside the breaker and is commonly referenced with the -1128 suffix. Operated at 48V DC, it draws about 50 mA to power the release. Schneider Electric lists MA11128 as End of commercialization, so current availability and support may vary; check with distributors or the manufacturer for the latest status before purchasing. This undervoltage release is used to safeguard equipment in control panels and industrial machinery where 48V control circuits govern safety interlocks and protective relays, ensuring the breaker trips promptly if the control supply collapses.