Square D LH36350 Molded Case Circuit Breaker

The LH36350 is designed for Square D I-Line panelboards and switchboards. This 3-pole L-frame breaker requires 6 inches of vertical mounting space on the I-Line bus stack.

The plug-on phase jaws push directly onto the vertical I-Line bus stack. A mounting bracket with captive screws secures the breaker body to the panel backpan, bracing it against short-circuit magnetic forces.

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

The thermal long-time trip is fixed at 350 amps. However, the instantaneous magnetic trip threshold is adjustable via a dial on the breaker face, allowing you to coordinate with downstream overcurrent devices.

Yes, the LH frame shares the exact physical dimensions and 6-inch I-Line mounting footprint as the standard LA frame. The LH36350 serves as a direct drop-in replacement while providing a higher short-circuit interrupting rating.

Ensure the panelboard is fully de-energized. Inspect the bus bars for pitting or debris, and confirm the breaker phase jaws are clean. After pushing the breaker onto the bus, properly torque the captive mounting screws to maintain a secure connection and prevent arcing.

Yes, the LH36350 is frequently used as a main or feeder breaker in series-rated combinations with downstream Square D branch breakers like the QO, QOB, or EDB series. Always verify the specific breaker combination in the manufacturer series rating tables.

Internal accessories for the legacy LH frame, such as shunt trips and auxiliary contacts, are factory installed. Opening the breaker case in the field to add these devices voids the UL listing.

Yes, in addition to its alternating current ratings, the LH36350 is UL listed for use on 250VDC systems with a 50kA direct current interrupting rating.