Square D | LLA36400U33X | Circuit Breaker | 400A | 3-Pole | 600V

Square D LLA36400U33X is a robust circuit breaker engineered for demanding electrical environments. With a 400 A rating, 3-pole configuration, and a 600 V operating capacity, this unit is purpose-built for 3-phase power distribution where reliability and precise compatibility are non-negotiable. Ideal for maintenance, retrofit, and replacement projects, it delivers a trustworthy solution when exact specs are required.

• Amperage: 400 A
• Poles: 3-Pole
• Voltage: 600 V
• Part number: LLA36400U33X
• Brand: Square D

Designed to fit legacy and service panels that call for this precise combination of amperage, pole count, and voltage, the LLA36400U33X is a dependable choice for professionals conducting panel upgrades or replacements. It provides the compatibility you need when upgrading 3-phase systems or restoring functionality in aging electrical infrastructure.

Key use cases

• Replacing a failed or aging circuit breaker in 3‑phase, 600 V systems
• Retrofit projects where a matching Square D spec is required to maintain panel labeling and performance
• Maintenance cycles and component refreshes in commercial or light industrial panels
• New installations that demand an exact 400 A, 3-pole, 600 V specification for reliability

Why choose this model? Because exact spec alignment matters in critical power environments. The LLA36400U33X offers a precise fit for compatibility with existing Square D panels and downstream components, reducing installation guesswork and helping you maintain consistent electrical protection across your system. When ordering, use the part number as your primary compatibility reference to ensure you’re selecting the correct unit for your panel configuration.

Practical guidance

• Before purchasing, verify that your panel accepts a 3-pole, 400 A, 600 V circuit breaker of the LLA36400U33X specification.
• Plan for proper de-energization, lockout/tagout procedures, and adherence to local electrical codes during installation.
• Keep the part number handy as the best reference for compatibility with your existing Square D equipment.