The Allen-Bradley 140U-I6C3-D12 Circuit Breaker is a 3-pole Molded Case Circuit Breaker (MCCB) with an I-Frame and a current rating of 120 Amps. It is a member of the Allen-Bradley 140U family of inverse time circuit breakers and as such, its response time is inversely proportional to the magnitude of the overcurrent. When the Allen-Bradley 140U-I6C3-D12 Circuit Breaker senses a high overcurrent, its response time is slower and this trips the circuit at a high velocity to protect the load, and if the overcurrent magnitude is not so high, the breaker takes a longer time to trip, allowing the process to stabilize without frequent interruptions. Both magnetic and thermal trip settings are fixed at the factory and they are not adjustable by the end-users. The Allen-Bradley I-Frame Molded Case Circuit Breakers are not adjustable.

The Allen-Bradley 140U-I6C3-D12 Molded Case Circuit Breaker comes with an interrupting rating/breaking capacity of 65 kA. The Horsepower ratings will depend on the applied voltage and they can be 20 Horsepower at 200 Volts AC, 20 Horsepower at 380 to 415 Volts AC, 40 Horsepower at 460 Volts AC, and 50 at 575 Volts AC.  The magnetic tripping range runs from 800 to 1600 Amps. Optional components are available for adaptations on the Allen-Bradley 140U-I6C3-D12 Inverse Time Circuit Breaker, including but not limited to rotary operators, flex cable operators, internal control modules, and auxiliary contacts. As with any type of circuit breaker, it always advisable to install the Allen-Bradley 140U-I6C3-D12 Circuit Breaker in a protected enclosure away from humid or dusty environments, in order to avoid contaminants such as dirt, dust, and lint from building up inside the operating mechanisms of the circuit breaker.