The Allen-Bradley 140U-K6D3-D40-MU Molded Case Circuit Breaker has a supply voltage of 480 Volts, a rated current of 400 Amps, an interrupting rating of 65 kA, and a 3-pole configuration. It provides Fixed Thermal/Adjustable Magnetic protection. The circuit breaker protects the circuits against overloads, ground faults, and short-circuits. It is normally used in branch and main circuit protection devices such as bus-bar trunking tap-offs, switchboards, panelboards, and individual enclosures. It offers an alternative for current-limiting that supplies a life-cycle interrupt to limit the energy that is allowed through. The Allen-Bradley 140U-K6D3-D40-MU Molded Case Circuit Breaker has international certifications that include the CCC, UL List, CE Mark, and CSA standards and it can be used with IE3 Motors (IEC 60034-30). It also complies with international standards such as the CSA22.2 (No.5), the UL489, and the IEC 60947-2 standards.

The Allen-Bradley 140U-K6D3-D40-MU circuit breaker has factory assembled internal control modules including the Auxiliary Contact (AX), Alarm Contact (AL), Auxiliary/Alarm Contact (AX/ AL) combination, Shunt Trip (SNT), and Undervoltage Release (UVT) modules. Each internal control module has its specified function in the circuit breaker. The Auxiliary Contact electrically shows when the breaker is either on or off. The Alarm Contact electrically shows when the breaker is tripped. The combined Auxiliary/Alarm Contact electrically shows the on and off status and the tripped status of the breaker. The Shunt Trip offers the circuit breaker remote tripping. The Undervoltage Release trips the breaker automatically during a voltage drop to a level ranging from 35 to 70% of the present value. The Allen-Bradley 140U-K6D3-D40-MU circuit breaker has a maximum ambient temperature rating of 40 degrees Celsius (104 degrees Fahrenheit) and a storage temperature range between -40 and 80 degrees Celsius (-40 and 176 degrees Fahrenheit). It is a compact device with dimensions of 140 x 108.5 x 205 millimeters.