Square D LDA36400U44X - 400 A, 3-Pole Plug-In Circuit Breaker | AmpState

Introducing the Square D LDA36400U44X — a robust 400 A, 3-pole plug-in molded case circuit breaker designed to safeguard branch circuits in panelboards and load centers. Engineered for dependable overcurrent and short-circuit protection, this breaker keeps critical electrical systems running smoothly in demanding environments.

Key advantages that matter in the field:

• Fast plug-in connection for rapid installation and easy replacement, minimizing panel downtime during maintenance or upgrades.
• Thermal-magnetic trip unit delivers stable, repeatable protection across a range of loads and temperatures, reacting quickly to faults while reducing nuisance trips from normal inrush.
• OEM-compatible fit designed to match with corresponding load centers and panelboards for a clean, reliable electrical interface.
• Three-pole, 400 A configuration provides solid protection for heavy feeders and three-phase circuits common in commercial and light industrial applications.
• Molded-case, plug-in construction offers rugged protection for the breaker mechanism, reducing risk of damage in dense panel installations and busy electrical rooms.

Ideal use scenarios:

• Residential-commercial panel installations where large feeder protection is required, such as multifamily dwellings or mixed-use buildings.
• Commercial facilities with three-phase equipment and motor loads, where quick replacement minimizes downtime after a fault.
• Light industrial environments with demanding fault-current levels, where reliable thermal-magnetic protection helps prevent equipment damage.

What to expect in practice:

• Consistent protection: the thermal-magnetic design provides predictable tripping behavior under overloads and short circuits.
• Maintenance efficiency: the plug-in style enables straightforward swaps without removing the panel cover or rewiring.
• Durable fit: molded-case construction resists impact and wear in active electrical spaces and service fleets.

Specifications at a glance

• Manufacturer: Square D
• Part Number: LDA36400U44X
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400 A
• Number of Poles: 3
• Mounting Style: Plug-in
• Application: Branch circuit overcurrent and short-circuit protection