Square D LA36300 Molded Case Circuit Breaker

The LA36300 features an I-Line style plug-in connection. The line side jaws plug directly into the vertical bus stack of a Square D I-Line panelboard or switchboard, while the load side uses traditional mechanical lugs for wire termination.

This breaker features an adjustable AC magnetic trip setting that ranges from 1500A on the low end to 3000A on the high end. This allows electricians to fine-tune the instantaneous short circuit trip threshold based on the specific load requirements.

No. The LA36300 has an I-Line plug-on mounting style and is strictly compatible with Square D I-Line panelboards and switchboards. It will not fit in NQ, NF, or QO series enclosures.

The standard factory load lugs accept either one 1 AWG to 600 kcmil conductor or two 1 AWG to 250 kcmil conductors per phase. The lugs are rated for both aluminum and copper wire.

Yes, the LA frame is part of the legacy Square D molded case circuit breaker family. For modernization or new builds, it is often superseded by the newer PowerPact L-Frame series, though the LA36300 remains heavily utilized for direct replacements in existing I-Line panels.

The LI trip code means the thermal-magnetic trip unit provides Long-Time overload protection and Instantaneous short circuit protection. On the LA36300, the thermal element is fixed, while the magnetic instantaneous element is adjustable.

Because the I-Line connection plugs directly onto the main panel busbar, the panelboard must be properly de-energized prior to installation to prevent severe arc flash hazards, strictly following OSHA and NFPA 70E safety protocols for bus-connected equipment.