The 140U-JTD3-D20 circuit breaker is a molded-case circuit breaker that has been designed to provide protection to different kinds of equipment such as induction motors and branch circuits, and it also provides electrical protection against abnormal currents that might cause severe damage to the whole circuit. This breaker has been manufactured, designed, and distributed by Allen-Bradley. It is strongly recommended to mount the breaker in a location that is accessible to technicians and supervisors so that once a fault has been detected and cleared, the breaker can be set back into normal operations. The Allen-Bradley 140U-JTD3-D20 molded-case circuit breaker comes with a fixed thermal and adjustable magnetic trips and it has all the specifications of Frame J breakers, including the general current rating of 250 Amps.

The Allen-Bradley 140U-JTD3-D20 molded-case circuit breaker can operate with its full rating at temperatures of up to 40 degrees Celsius and at altitudes of up to 2800 meters above sea level. If the breaker is going to be installed in environments that exceed these specifications, it is necessary to derate the breaker first. If these specifications are known before ordering the breaker, a specific calibration can be ordered from the factory. The Allen-Bradley 140U-JTD3-D20 molded-case circuit breaker comes with two different trip ratings for its different trip mechanisms. The thermal mechanism trip rating is 1000 Amps and the magnetic mechanism trip rating is 2000 Amps. This breaker comes with three poles and all its cables and wirings need to be designed for operations at temperatures higher than 75 degrees Celsius. It operates with a voltage range of 200 to 600 Volts and a frequency of 50 Hertz. The voltage that is employed affects the exact rating of the breaker.