The 140U-D6D3-C12 circuit breaker is an important protection component that helps to prevent damage to equipment. This model is part of the 140U-D series by Allen-Bradley/Rockwell Automation. The unit is used in different industries and for a variety of applications. It is intended for global use and it complies with the UL and European standards. The 140U-D6D3-C12 circuit breaker provides overload protection according to the IEC/EN 60947-2, UL489, and CSA 22.2 standards. This molded-case circuit breaker has a high interrupting rating and it has a higher overall rating for panel short circuits according to the National Electrical Code (NEC). The 140U-D6D3-C12 has 3 poles and a rated current of 12 Amps. The breaking capacity at 50 Hertz operating frequency is 65 ICU/50 ICS at 400 to 415 Volts and 525 Volts, while its breaking capacity at 690 Volts is 10 ICU/6 ICS.

The 140U-D6D3-C12 breaker unit has a small footprint that reduces panel space costs and provides a 100% rating at up to a current of 15 Amps. The device can be used for back-feeding purposes at 240 Volts and 480Y/277 Volts. This unit is designed for feeder circuits, heating and air conditioning, control circuits, and switching devices. All the available accessories are meant to be installed in the field. The 140U-D series offers the following accessories: connection modules, flexible wire modules, extension shaft support, compact busbars, feeder terminals, and load terminal covers. Accessories can be ordered separately under their own catalog numbers provided by the manufacturer. The 140U-D6D3-C12 circuit breaker can be used for the main disconnect switch when combined with the accessories. The thermal-magnetic circuit breaker has a total power loss of 7.5 Watts maximum. The 140U-D6D3-C12 breaker has a solid tolerance to vibrations/shock and its ambient temperature is between -25 and 60 degrees Celsius (-13 and 140 degrees Fahrenheit).