The 140U-J3D3-D22 circuit breaker is a Bulletin 140U series circuit breaker device. It has been designed and manufactured by Allen-Bradley. It can provide protection to 3 circuits at a time with its 3 poles. It is a 3-phase circuit breaker with a current rating of 225 Amps. It has a voltage rating of 600 Volts. The interrupt rating of the circuit breaker is 35 kA at 480 Volts. It can trip for both thermal and magnetic overload conditions. The trip feature is fixed in this circuit breaker variant. The 140U-J3D3-D22 circuit breaker is enclosed inside a molded case. An on/off lever is present in the front panel to power the circuit breaker on and off. Along with the power switch, a red button is available which can trip the circuit manually. This is usually done to test the breaking functionality of the circuit breaker. The front part comes with both line and load side lug terminals.

The 140U-J3D3-D22 circuit breaker is able to withstand different interrupt ratings with a frequency of 50/60 Hertz. The circuit breaker complies with different industrial and environmental standards. The environment temperature should be maintained between -8 and 60 degrees Celsius. The humidity can only reach a maximum level of 95% non-condensing relative humidity for regular operation. The circuit breaker can be used easily at up to an altitude of 2000 meters above sea level without losing its efficiency. During the installation of the 140U-J3D3-D22 circuit breaker, the main power supply to the breaker should be properly disconnected to avoid electrical hazards and injuries. The airflow between the breaker and the ventilation source for the circuit breaker should not be obstructed.