Siemens / ITE JJ3B300 – 300A 3 Pole Molded Case Circuit Breaker New Release

Rated 25 kAIC at 480V, the Siemens JJ3B300 is a 3-pole, 300A molded case circuit breaker designed for legacy power distribution systems. It utilizes a proven thermal-magnetic trip mechanism with adjustable magnetic functions, providing dependable protection for commercial loads. This bolt-on breaker mounts into Siemens P4 and P5 panelboards, SB switchboards, and FC-series interiors. As a direct cross-reference for the JXD63B300, it ensures a perfect fit without aftermarket adapters.