The 140U-J2D3-D25 Molded Case Circuit Breaker (MCCB) is a high-performance compact breaker from Allen-Bradley/Rockwell Automation. It has a size J frame, 3 poles, and 250 Amps of frame current rating. The rated operational voltage of the breaker is 400 or 480 Volts AC and the current rating is 250 Amps. It comes with 25 Kiloamps of interrupting rating and 11.4 pounds of approximate shipping weight. This MCCB provides thermal protection for industrial control panels as well as branch circuits. Thermal protection can be provided through the use of a bimetallic heating element similar to overload relays. Its reverse loop design assists the opening of the contact during a short circuit by using the magnetic forces created by the current flow in the opposite direction.

The 140U-J2D3-D25 Molded Case Circuit Breaker requires less maintenance than other circuit breakers. However visual inspection, lubrication, cleaning, testing, tripping, and insulation resistance tests help to maintain reliable operation. Some of the accessories that are available for this breaker include a flex cable operator, end cap kit, insulating terminal shields, motor protectors, and phase barriers. This MCCB can be used in an industrial control panel which is known as a feeder circuit. It is UL listed as a current limiting breaker. If the ambient temperature of the 140U-J2D3-D25 Circuit Breaker is below the standard 40 degrees Celsius rating, the mechanical operation of the breaker could be affected. It has a tripping mechanism that releases the energy within the mechanism to open the contact quickly. The tripping unit can be the thermal-magnetic type or the microprocessor type. This molded case circuit breaker can be used to protect and control electrical power transmission networks in industrial applications.