Square D LAL26300MB Molded Case Circuit Breaker

The MB suffix means the breaker is equipped with a short handle. This modified actuator provides extra clearance, allowing panel doors to close securely in space-constrained enclosures and switchboards.

The terminals accept either one 1 AWG to 600 kcmil wire, or two 1 AWG to 250 kcmil wires per phase. The lugs are rated for both aluminum and copper conductors.

This breaker uses a thermal-magnetic trip unit with a fixed thermal element for long-time overload protection and an adjustable magnetic element for instantaneous short-circuit protection. The magnetic trip threshold is set via a dial on the face of the breaker.

Yes. The LAL26300MB shares the exact same electrical ratings, physical footprint, and unit-mount design as the standard LAL26300. The only difference is the short handle on the MB variant.

The LAL26300MB is a unit-mount, feed-thru circuit breaker. It bolts directly to the backplate or mounting pan of compatible Square D switchboards, panelboards, and enclosures, rather than plugging into a busbar.

You can use the push-to-trip button located on the front of the breaker. This allows you to manually trip the mechanism and verify proper mechanical function without exposure to live electrical parts.

Yes, this 2-pole breaker is rated for use in DC circuits up to 250VDC, providing a 10kA interrupting rating for those applications.

For modern upgrades, Schneider Electric replaces the legacy LAL series with the PowerPacT L-Frame molded case circuit breakers. You must verify panel space and mounting hardware compatibility when retrofitting to the newer PowerPacT series.