The 140U MCB series of molded case circuit breakers from Allen-Bradley/Rockwell Automation features circuit breakers that are listed for global applications. The 140U MCB circuit breakers, like other molded case circuit breakers, are used in a system to provide protection against overcurrents as well as short circuit protection. Note that a short circuit can reach a current of up to 100,000 Amps. To provide reliable protection, molded case circuit breakers have an arc chamber which surrounds the switching contacts. The chamber is made of splitter plates and chutes which help in drawing the arc away from the contacts during a short circuit. An arc is formed by opening the contacts. These breakers provide up to 6 times higher interrupting ratings than other miniature breakers. The Allen-Bradley 140U molded-case circuit breakers also include accessories such as load terminal covers, feeder terminals, eco connection modules, and extension shaft support.

The Allen-Bradley 140U MCB circuit breakers are current limiting circuit breakers that are listed by the Underwriters Laboratories. This series of breakers have a high interrupting capacity and they are suitable for backfeeding at a voltage rating of 240 Volts and 480Y/277V. The 140U MCB series has breakers with a current rating of between 0.5 Amps and 30 Amps. Also, these breakers are available in either 2 or 3 poles. The 140U MCB circuit breakers are 100% rated at up to 10 Amps. The 140U MCB series is compliant with standards such as the CSA C22.2, No.5, IEC/EN 60947-1, IEC/EN 60947-2, and UL 489. Under the UL and the CSA standards, this family of circuit breakers has a rated insulation voltage of 600 Volts. The 140U MCB series has mechanical and electrical lifespans of 100,000 and 10,000 operations, respectively. These circuit breakers have a rated operating ambient temperature of between -40 degrees Celsius and 80 degrees Celsius. One of the benefits of these breakers is that they come with a compact design that consists of a width of 45 millimeters, a height of 102 millimeters, and a depth of 85 millimeters, which help the breakers save panel space.