The Allen-Bradley/Rockwell Automation 140U-JD6D3-D10 Circuit Breaker is a Molded Case Circuit Breaker or MCCB that is designed to protect industrial machines from excessive or erratic currents. The 140U-JD6D3-D10 Circuit Breaker will trip and stop the flow of electric current in a machine when it is triggered by a current that is equal to or higher than its maximum current setting. This device will help to prevent power loss, lost work time and productivity, extensive machine damage, fires, and injury to the users. This device is UL and IEC certified. The 140U-JD6D3-D10 Molded Case Circuit Breaker must operate in its specified temperature range at all times because excessive heat may damage it or cause it to trip when nothing is wrong with the level of electric current in the host machine. This circuit breaker is meant to operate at the full extent of its powers at a maximum ambient temperature of 104 degrees Fahrenheit or 40 degrees Celsius.

The Allen-Bradley/Rockwell Automation 140U-JD6D3-D10 Molded Case Circuit Breaker can operate a temperature higher than 104 degrees Fahrenheit or 40 degrees Celsius too, but it must be derated first and its operating will be limited. It must also be derated if it is installed in an industrial environment located at an altitude higher than 6000 feet or 1829 meters above sea level because the thin air found at high altitudes makes it more difficult for the circuit breaker to be air-cooled or to maintain a stable operating temperature. The 140U-JD6D3-D10 Circuit Breaker can be mounted in almost any position, but it is a violation of the National Electrical Code Article 240-81 to mount this circuit breaker in a vertical position where the on-switch position is pointing down instead of up.