The 140U-H6C3-D12 circuit breaker is a fixed-thermal and fixed-magnetic circuit breaker that has been manufactured and designed by Allen-Bradley. This breaker has been designed to operate with a high interrupting rating that provides overload and short-circuit currents to different devices that run from the motors to a different group of devices. Circuit breakers have a mechanism that detects abnormal current and makes it perform a tripping action so that this current flow is stopped before it enters the conduits. This way, it protects and preserves conduits and equipment. The Allen-Bradley 140U-H6C3-D12A fixed-thermal and the fixed-magnetic circuit breaker has an interrupting capacity of 60 to 69 kiloamps and it operates at a frequency of 60 Hertz. This breaker must not be exposed to extreme temperatures since high temperatures can affect the thermal detection mechanism of the breaker. It is recommended to have ventilation equipment around the breaker if the temperatures rise above 75 degrees Celsius.

The Allen-Bradley 140U-H6C3-D12 fixed-thermal and fixed-magnetic circuit breaker need to be attached to a compatible motor. When it comes to compatibility, it is important that the current rating of the motor matches the protection level provided by the breaker. This breaker can be installed in series with other breakers that have the same capacity to protect a whole circuit of equipment. The Allen-Bradley 140U-H6C3-D12 fixed-thermal and fixed-magnetic circuit breaker can be installed in a cabinet. The interrupting rating of the breaker varies according to the voltage applied and that voltage can range from 380 to 690 Volts. The breaker comes with flex cables and rotary operators.