Square D LDA36400U33X - 400 A, 600 V, 3-Pole Plug-In Circuit Breaker | AmpState

Meet the Square D LDA36400U33X—a 400 A, 600 V, 3-pole plug-in molded case circuit breaker built to guard panels and distribution systems with precision. Designed for dependable branch circuit overcurrent and short-circuit protection, this unit is the smart choice for reliable power delivery in panelboards and loadcenters across residential, commercial, and light industrial applications.

Why this breaker stands out

• Fast plug-in connection for quick installation and effortless replacement, minimizing downtime on service calls or upgrades.
• Thermal-magnetic trip unit delivers stable, repeatable protection across temperature variations, instantly responding to short circuits while smoothly handling overloads.
• 3-pole configuration ensures balanced protection for three-phase circuits, essential for commercial and light industrial setups.
• 400 A, 600 V rating provides robust protection for high-demand feeders and main distribution paths.
• OEM-compatible with matching Square D load centers and panelboards, helping maintain a clean, code-compliant electrical distribution system.
• Durable molded-case design offers rugged protection in demanding environments while maintaining a compact footprint for installation flexibility.

Technical snapshot

• Manufacturer: Square D
• Part Number: LDA36400U33X
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400 A
• Voltage Rating: 600 V
• Number of Poles: 3
• Mounting Style: Plug-in
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use scenarios

Site this breaker in service entrances, main panels, or distribution centers where three-phase power is distributed. It’s a reliable choice for electricians upgrading aging panels, engineers designing new panel assemblies, or facility managers consolidating protection for motor loads and lighting circuits. Its high current rating makes it suitable for feeder lines in commercial spaces, light industrial equipment rooms, or data centers with moderate power demands.

Practical benefits and outcomes

• Minimize downtime with a plug-in design that simplifies maintenance and reduces circuit-breaker replacement time.
• Maintain consistent protection across varying loads and ambient temperatures thanks to the thermal-magnetic trip system.
• Preserve panel integrity and continuity by using a breaker that aligns with OEM load centers, helping ensure correct fit and trip characteristics.
• Provide robust safety margins for critical circuits while supporting straightforward expansion or reconfiguration of the electrical system.

Getting it right

For best results, pair the Square D LDA36400U33X with compatible OEM load centers and panelboards, verify three-phase requirements, and follow local electrical codes during installation. This unit is purpose-built for dependable branch-circuit protection where speed, reliability, and durability matter most.