The 140U-M5X3 Breaker Frame is a compact molded frame from Allen-Bradley/Rockwell Automation. It belongs to the bulletin 140U MCCB accessories product line. Its frame ratings are Size M, 3 poles, and 800 Amps. The ambient temperature of the frame is 40 degrees Celsius. Its compact design ensures easy mounting and wiring. Since the entire unit is enclosed with a molded case insulator, the generated arc is not discharged. The design of the breaker ensures reduced maintenance and reduced inventory. The 140U-M5X3 Breaker Frame is also suitable for use in open and enclosed switchboards and distribution systems. It has an efficient modular design that enables greater flexibility in industrial switchboards to enhance electrical power distribution. According to the frame size and the basic framework of the plastic shell, the breaker can hold a maximum of 800 Amps of rated current. It also utilizes a molded case switch.

The frame L breakers like the 140U-M5X3 Breaker Frame are available as complete breakers or as separate accessories such as frames, trip units, and terminals to provide greater flexibility for customers. The accessories may be field-installed or factory-installed. The approximate dimension of the frame is 16 x 8.25 x 4.375 inches. The mounting hardware, copper, and aluminum terminal lugs all come as separate accessories. Dust, oil, and corrosive elements must not come into direct contact with the device. Keeping these elements away from the breaker frame ensures that it will have a long mechanical life. During installation, make sure not to install the 140U-M5X3 Breaker Frame in direct sunlight because the device may malfunction due to an excessive temperature. During assembling, make sure that the control circuit and field connect terminals are tightened with 0.7 N-m of torque.