The 140UE-M5X3 Circuit Breaker is an IEC Molded Case Circuit Breaker manufactured by Allen-Bradley/Rockwell Automation as part of the 140U MCB series. It features Frame M frame type that has a current rating of 800 Amps with a breaking capacity or interrupting rating of 50 to 59 kiloamps at 400 Volts AC. This 3-pole circuit breaker comes with the frame-only open enclosure as well as the electronic and disconnector protection type. This circuit breaker and other circuit breakers under the Bulletin 140UE series have a current range of 15 to 1250 Amps with an electronic current rating of 70 to 1250 Amps, a molded case switches current rating of 160 to1250 Amps, and a thermal-magnetic current rating of 15 to 800 Amps. It is a three-pole molded case circuit breaker with features including flex cable operating mechanisms, factory or field-installed accessories, and a rotary variable depth operating mechanism.

At 50 Hertz, the 140UE-M5X3 circuit breaker has a breaking capacity of 65 kiloamps at 220 to 240 Volts AC, 50 kiloamps at 380 to 415 Volts AC, 25 kiloamps at 500 Volts AC, and 20/10 kiloamps at 690 Volts AC. At 60 Hertz, it has an interrupting rating of 65 kiloamps at 240 Volts AC, 50 kiloamps at 480 Volts AC, and 25 kiloamps at 600 Volts AC. Some internal accessories of the Allen-Bradley 140UE-M5X3 circuit breaker include alarm (trip) contacts, auxiliary shields, a shunt trip, and an under-voltage release. The external accessories are a lockable hasp, terminal covers, terminal lugs, end cap kits, phase barriers, a slide bar interlock, a flex-cable operating mechanism, and a variable depth rotary operating mechanism. The 140UE-M5X3 circuit breaker has a standard compliance rating for the CE, KEMA-KEUR, and IEC 60947-2 standards.