The Allen-Bradley 140U-K3D3-D20 UL listed Molded Case Circuit Breaker is a device that is intended to provide short-circuit and thermal overload protection to industrial control panel and industrial applications. The 140U-K3D3-D20 Circuit Breaker belongs to the 400 Amps rated K-Frame circuit breaker family, and it is designed with a high interrupting rating that is 6 times higher than the interrupting rating of the conventional circuit breakers in its class. This circuit breaker has a very compact design that helps it to save panel space and operation costs, and it also serves as the main disconnect means for a control panel. The 140U-K3D3-D20 Circuit Breaker can be used in feeder circuit applications and also in heating, air conditioning, and refrigeration (HACR) applications.

The 140U-K3D3-D20 Circuit Breaker has a rated operating voltage of 480 Volts AC and a maximum trip current rating of 200 Amps. It has a maximum interrupting of 35 Kilo-Amps (at 480 Volts AC) and a rated impulse withstand of 6000 Volts. This circuit has a factory-rated mechanical lifespan of 100,000 operations and an electrical lifespan of 10,000 operations. The 140U-K3D3-D20 Circuit Breaker has a release unit made up of a fixed thermal and adjustable magnetic trip unit (electromechanical). This trip unit offers a fixed thermal trip rating of 200 Amps and an adjustable instantaneous trip setting between 1000 and 2000 Amps. The 140U-K3D3-D20 Circuit Breaker provides thermal overload protection by using a bimetallic heat element and it uses an electromagnetic device for instantaneous trip action. It comes with standard bolt-on screws (terminal lugs are sold separately), and it has a lever-type toggle handle for control (its positions are ON, OFF, or TRIP).