The 140U-JTD3-D12 circuit breaker is a molded-case circuit breaker that has been designed and distributed by the Allen-Bradley company. This breaker protects industrial machines against the current anomalies that occur during operation. Current generally flows into the conduits until it reaches its final destination, and this breaker works as a barrier between current and the final equipment and if there is an abnormal situation, it stops the current flow until the fault condition has been cleared and the breaker has been reset by the operators to start operating again in the same way that it did before. The Allen-Bradley 140U-JTD3-D12 molded-case circuit breaker operates with a current rating of 250 Amps, a thermal rating of 100 Amps, and a magnet current rating of 500 to 1000 Amps. This breaker comes with a fixed thermal and adjustable magnetic trip unit. The approximate voltage rating for this breaker goes from 240 to 600 Volts.

The Allen-Bradley 140U-JTD3-D12 molded-case circuit breaker uses three poles that are the devices that perform the interrupting action once a fault has been detected by the trip unit. This unit operates at full power within the correct temperature rating and it also has a magnet that detects short-circuit currents. It is recommended to install the Allen-Bradley 140U-JTD3-D12 molded-case circuit breaker in an enclosure that provides a mounting mechanism and that protects the breaker from coming into contact with hazardous materials that tend to corrode and damage the structure of the breaker. The breaker has an approximate weight of 2.5 kilograms and it has a compact design that fits every installation space. The ambient air temperature must not exceed 40 degrees Celsius.