The ABB MOE 220-250Vac/dc T4-5 is an under-voltage release (UVR) accessory, also known as an undervoltage trip coil, designed for ABB's Emax 2 (E2) series of low voltage air circuit breakers (ACBs). Its primary function is to automatically trip (open) the main breaker when the control supply voltage drops below a specified threshold, thereby protecting equipment from damage due to undervoltage conditions (e.g., brownouts, phase loss) and ensuring safety upon power loss.