Square D LDL36400U31X - 400 A, 600 V, 3-Pole Circuit Breaker | AmpState

The Square D LDL36400U31X is a 400A, 600V, 3-pole molded-case circuit breaker engineered to deliver reliable branch circuit overcurrent and short-circuit protection where space and performance matter. Built to integrate with matching OEM load centers and panelboards, it’s a dependable choice for electrical distribution in homes, offices, and light industrial environments.

Why this breaker stands out

• Compact molded-case design minimizes footprint and maximizes panel space, making it easier to fit into tighter electrical enclosures without sacrificing protection capabilities.
• Thermal-magnetic trip unit delivers stable, repeatable protection by combining precise current sensing with a fast magnetic trip for fault clearing — helping reduce nuisance trips while maintaining safety.
• 3-pole configuration ideal for three-phase distribution or multi-pole switching, enabling clean protection of three conductors in one device.
• OEM-compatible guaranteed compatibility with Square D load centers and panelboards for straightforward installation and reliable seating.
• High-current capability rated at 400A and 600V, suitable for medium to heavy distribution circuits in commercial or light industrial settings.

Practical applications

• Residential and small commercial panels requiring robust branch-circuit protection for heavy circuits like subpanels, motors, or HVAC equipment.
• Commercial office spaces with three-phase distribution needing dependable protection across critical feeders.
• Light industrial enclosures where space is at a premium but protection levels must stay high and consistent.

How it integrates into your electrical system

• Install in compatible Square D panelboards or load centers; ensure downstream circuits are sized to the 400A rating and that wiring is appropriate for 600V systems.
• Thermal-magnetic trip ensures dependable disconnection under overload or short-circuit, helping prevent damage to downstream devices and wiring.

Technical snapshot

• Manufacturer: Square D
• Part number: LDL36400U31X
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 400A
• Voltage rating: 600V
• Poles: 3
• Application: Branch circuit overcurrent and short-circuit protection

Designed for the way professionals plan electrical distribution — thoughtful space efficiency, precise protection characteristics, and seamless OEM compatibility. If you’re upgrading a panel or stocking service vans with reliable protection devices, the LDL36400U31X from Square D delivers the performance you need with confidence. Purchase with AmpState for trusted support and genuine Square D reliability.