Square D LJA36400U33X 400A 3P 600V Circuit Breaker | AmpState

Meet the Square D LJA36400U33X—a robust circuit breaker designed for reliable protection in panelboards, load centers, and electrical distribution systems. With a 400 A rating, 3 poles, and a 600 V capacity, it’s built to handle demanding three‑phase applications while maintaining dependable performance across your electrical infrastructure.

Why this matters: when maintenance or expansion requires a direct part-number match, this LJA36400U33X from Square D ensures compatibility and quick replacements, minimizing downtime and simplifying spare inventory management for teams and contractors.

• Direct part-number match: A precise replacement component that aligns with existing panels and assemblies, reducing guesswork during maintenance.
• High-capacity protection: 400 A rating safeguards feeders and distribution circuits from overloads, while 3 poles provides balanced protection for three‑phase systems.
• Wide compatibility: Suitable for panelboards, load centers, and electrical distribution networks, supporting both retrofit and new installations.
• Proactive stocking: Ideal for spare inventory—keep critical protection ready to deploy when emergencies hit.
• Trusted heritage: Square D is known for durable, dependable protection devices—backed by AmpState availability.

Key specifications

• Manufacturer: Square D
• Part Number: LJA36400U33X
• Product Type: Circuit Breaker
• Amperage: 400 A
• Poles: 3
• Voltage Rating: 600 V

Ideal for: maintenance technicians, panel builders, electrical distributors, and facility managers who need a reliable, exact-fit protection device for three-phase systems.

Need help confirming fit? Message us and we’ll help verify compatibility with your specific panel or distribution setup.