The 1020028 is a UL 1077 supplementary protector from the TMC 7 series, designed to provide reliable overcurrent protection. This device features a snap-action mechanism to reduce contact wear and a trip-free design that prevents closing the circuit during an overcurrent event, enhancing safety. The series offers dual-rated (AC/DC) versions and supports optional snap-on accessories, including shunt trips, alarms, and auxiliary contacts for additional functionality. Common applications include motor control circuits, lighting controls, PLC I/Os, and protecting other sensitive equipment.