The 140U-L3D3-D40 Molded Case Circuit Breaker is a product from Allen-Bradley/Rockwell Automation that is manufactured as part of the 140U MCB product line. It comes with an L Frame with a current rating of 600 Amps. The circuit breaker has an interrupting rating or breaking capacity of 30 to 39 kiloamps at 480 Volts. The Allen-Bradley 140U-L3D3-D40 Circuit Breaker has fixed thermal and adjustable magnetic protection with a breaking capacity or interrupting rating of 45 kiloamps at 400 Volts and 35 kiloamps at 480 Volts. These are the interrupt ratings on a thermal trip and an operational current rating of 250 Amps with an overall current rating of 4000 Amps. They also feature high interrupting ratings in compact dimensions and they are globally accepted and rated for compliance with the UL, CSA, IEC, KEMA-KEUR, and CE standards, which means they can be universally used in worldwide applications.

Other notable features of the 140U-L3D3-D40 Circuit Breaker include field-installed internal control modules, rotary operators, flex cable operators, and molded case switches. The L Frame size circuit breakers have an interrupting rating of 45,70 kiloamps at 380 to 415 Volts, 35 to 65 kiloamps at 480 Volts, 25 to 35 kiloamps at 600 Volts, and 20 to 25 kiloamps at 690 Volts. Generally, the Bulletin 140U molded case circuit breakers are rated for 15 to 1200 Amps of current with an electronic current range of 70 to 1200 Amps with long time or short time settings, long-time or short-time or high instantaneous settings, long time or short time or ground fault and long-time, short time, high instantaneous, and ground fault trip settings. The 140U-L3D3-D40 Circuit Breaker also has a thermal-magnetic current range of 15 to 800 Amps, and a molded case switch current rating of 125 to 1200 Amps.