Siemens JL3B300U Molded Case Circuit Breaker

Siemens JL3B300U Molded Case Circuit Breaker is a 3‑pole, bolt‑on molded case switch from the JL frame family rated for 300 A and up to 600 V, designed to protect low‑voltage distribution feeders and motor circuits in commercial and industrial equipment. It uses a thermal‑magnetic trip unit to provide robust overload protection and short‑circuit interruption, with an interrupt rating of 35 kA, enabling safe clearance of fault currents in typical distribution setups. Built for rugged panel installation, the JL3B300U combines compact bolt‑on mounting with precise trip performance to guard feeders and branch circuits in power distribution panels and switchgear. This unit is the 3‑pole representation of Siemens’ JL lineup, offering dependable protection in applications where a single, reliable MCCB with a 300 A rating is required.