The 140G-K3X3 circuit breaker is a molded case circuit breaker made by Eaton Cutler-Hammer. This device is part of the 140G series of circuit breakers that run on a voltage of 600 Volts AC and that come with K frames and current ratings of 400 Amps. The 140G-K3X3 circuit breaker features an interrupting rating of 35 kA, 3 poles, bolt-on connection, and 3 phases. The 140G circuit breakers have the li–long-time and instantaneous functions as well as a variety of mounting selections and approvals from the UL489, IEC 60947-2, CCC, CSA, CE, UL, and CSA standards. It is known for providing overcurrent protection for equipment and conductors by opening automatically before the current reaches a value that will cause an excessive and dangerous temperature in the conductors or conductor insulation. Additionally, this circuit breaker can serve as the primary disconnecting mechanism for a control panel.

The protection that the 140G-K3X3 circuit breaker provides is protection from low overcurrents and short-circuit currents. Other features of the 140G-K3X3 molded case circuit breaker include an interrupting rating of 35 kA at 480 Volts AC and one of 50 kA at 415 Volts AC, a frequency rating of 50 to 60 Hertz, and a maximum temperature rating of 104 degrees Fahrenheit. It is suitable for use or storage in environments with a temperature range of -40 to 176 degrees Fahrenheit. This circuit breaker is a customer-friendly accessory that is designed to help with the quick and easy set-up process of almost any project type. Most of the circuit breakers like the 140G-K3X3 circuit breaker have electronic protection, but some also have thermal-magnetic protection which is the same protection as the electronic protection except that it allows for the customization of the protection curves for various specific applications.