Square D LJL36400U33X - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

Meet the Square D LJL36400U33X—a 400 A, 600 V, 3-pole molded case circuit breaker engineered to deliver dependable branch-circuit overcurrent and short-circuit protection in panelboards and loadcenters. Designed for residential, commercial, and light industrial environments, this unit helps you safeguard critical circuits with precise, reliable performance.

• Ampacity and voltage: 400 A rated, 600 V withstand capability for high-demand feeders and larger branch circuits.
• Three-pole design: Ensures simultaneous disconnection of all conductors in 3-phase systems, enhancing safety and trip assurance.
• Thermal-magnetic trip unit: Delivers stable, repeatable protection by responding promptly to both overloads and short circuits, with trip characteristics that adapt to varying load conditions.
• Compact molded-case construction: Efficiently uses panel space, helping you fit this protection device into crowded or compact panelboards without sacrificing performance.
• OEM compatibility: Compatible with matching Square D OEM loadcenters and panelboards, supporting worry-free replacement and reliable fitment.
• Versatile applications: A solid choice for branch-circuit protection in residential service panels, light commercial installations, and select industrial panels that require robust 400 A protection.

Why this 3-pole molded case breaker stands out: it combines a high current rating with a compact form factor, enabling you to protect large lighting, motor, and power distribution circuits in a single, easy-to-service device. The thermal-magnetic trip mechanism reduces nuisance tripping in environments with variable loads, while the guaranteed compatibility with Square D panel systems simplifies selection and maintenance for installers and facility managers alike.

Ideal use cases

• Feeding high-demand branch circuits in commercial or light-industrial panelboards
• Main or sub-feed protection for large electrical rooms and service panels
• Replacement in OEM Square D loadcenters where a 3-pole, 400 A breaker is required

Technical snapshot

• Manufacturer: Square D
• Part number: LJL36400U33X
• Type: Thermal-magnetic molded case circuit breaker
• Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

With the Square D LJL36400U33X in your panel, you gain a dependable, high-capacity protection solution that fits seamlessly into compatible Square D systems and workflows. For installers and facility teams looking to maintain safe, reliable electrical distribution while optimizing panel space, this breaker offers a precise balance of capacity, protection, and compatibility.