Square D LJA36400U31X 400A 3P 600V Circuit Breaker, Plug-On | AmpState

Meet the Square D LJA36400U31X — a high-capacity, plug-on circuit breaker engineered for dependable protection in panelboards, load centers, and electrical distribution systems. Designed with retrofit projects in mind, this 400 A, 3-pole device keeps your part numbers consistent for easier maintenance planning and faster service calls.

• Amperage: 400 A
• Poles: 3 Poles
• Voltage: 600 V
• Mounting: Plug-On
• Manufacturer: Square D
• Part Number: LJA36400U31X
• Typical Applications: Panelboards, Load centers, Electrical distribution networks

The LJA36400U31X stands out where uptime and reliability matter. Its plug-on design streamlines installation, reduces service time during upgrades, and provides solid, repeatable protection for three-phase circuits in commercial and industrial environments. By choosing this model, you align your distribution protection with a trusted brand and a part number that supports streamlined maintenance and inventory management.

Use cases and practical benefits

• Retrofit and upgrade projects where maintaining a consistent part number simplifies ordering and sparing.
• Maintenance planning for ongoing electrical distribution maintenance, minimizing downtime during breaker swaps.
• New installations in panelboards and load centers that require a rugged, 3-pole 600 V protection device with plug-on mounting.
• Spare-part strategy for facilities that rely on Square D components to reduce procurement lead times.

Need help matching a part number or confirming compatibility with your panel or distribution setup? AmpState provides guidance to verify fit and ensure a correct, secure installation. Availabe from AmpState, with support to confirm fit and answer technical questions about the LJA36400U31X.

Choose the Square D LJA36400U31X for dependable, plug-on circuit protection that keeps your electrical distribution running smoothly—now and in the future.