UM (V-EA) Circuit Breakers Altech UM (V-EA) Circuit Breakers are UL 508-listed manual motor controllers that are suitable as motor disconnects. These DIN-rail-mounted circuit breakers are thermal magnetic and have a width of 17.5mm per pole. The series features a 0.3A to 60A current rating, 277VAC voltage rating, and 10kA short circuit withstand capacity. Altech UM (V-EA) Circuit Breakers are ideal for use in AC motor starting, AC general use, AC resistance, AC discharge lamp, and AC incandescent lamp applications.