The 140U-K0D3-D20 circuit breaker is a thermal-magnetic circuit breaker that has been designed and distributed by Allen-Bradley/Rockwell Automation. This breaker has all the necessary components to protect a machine by the means of an interrupting action that impedes abnormal current from flowing into equipment. Abnormal current conditions can be over current, under current, and short-circuit current conditions. The breaker can be used as a single protection device or it can be installed in a series with other identical breakers to provide further protection. The Allen-Bradley/Rockwell Automation 140U-K0D3-D20 thermal-magnetic circuit breaker has a current rating of 400 Amps that depends on the voltage that is applied. Different voltage levels modify the interrupting rating of the breaker. It operates with a voltage range of 200 to 600 Volts and a frequency of 50 Hertz. All of these values are affected by conditions that exceed the recommended ones. It is important to note the specifications of the environment where the breaker is going to be installed and to use these specifications to provide a higher level of protection.

The Allen-Bradley/Rockwell Automation 140U-K0D3-D20 thermal-magnetic circuit breaker can be installed in any position including vertical, horizontal, and angled positions. It can withstand a maximum temperature of 40 degrees Celsius when it is operating with its full ratings, although it can also operate at a temperature of up to 75 degrees Celsius if it is derated and calibrated at that specific temperature. The same is true about different operating altitudes for this breaker. The Allen-Bradley/Rockwell Automation 140U-K0D3-D20 thermal-magnetic circuit breaker comes in the Frame K product line of the 140U series, it comes with three poles, and it has a thermal and magnetic trip unit that enables it to detect different kinds of abnormal current.