Square D LRA36400U31X - 400 A, 600 V, 3-Pole Plug-In Circuit Breaker | AmpState

Square D LRA36400U31X (400 A, 600 V, 3-Pole) Plug-In Molded Case Circuit Breaker is designed to deliver dependable branch-circuit overcurrent and short-circuit protection inside panelboards and load centers. Built for quick installation and reliable long-term performance, it’s a smart choice when upgrading or expanding electrical systems in residential, commercial, and light industrial settings.

Why this breaker stands out

• Fast plug-in connection minimizes installation time and simplifies replacement, reducing downtime when servicing panelboards or upgrading circuits.
• Thermal-magnetic trip unit provides stable, repeatable protection by combining time-delay overload sensing with instantaneous short-circuit response for enhanced circuit safety.
• OEM compatibility designed to work with matching Square D load centers and panelboards, ensuring a secure fit and consistent performance.
• High-current, low-voltage capability rated for 400 A at 600 V, making it suitable for demanding branch circuits in a range of installations.
• Triple-pole configuration delivers robust protection for three-phase systems, helping prevent cascading faults and equipment damage.

What problems it solves

In facilities with heavy electrical loads or expanding panels, the LRA36400U31X offers a reliable, immediate response to short circuits while providing smooth, predictable performance during longer overloads. Its plug-in design reduces field wiring complexity, and its thermal-magnetic mechanism helps prevent nuisance trips without sacrificing protection during real faults.

Ideal applications and use cases

• Residential upgrades where a high-current, three-pole protection device is required in main or subpanels.
• Commercial electrical rooms and light industrial setups needing dependable branch-circuit protection for motor loads, HVAC, lighting, and feeders.
• Panelboard and load center modernization, replacement, or expansion projects where fast plug-in installation is advantageous.

Technical snapshot, in plain terms: Square D LRA36400U31X is a 400 A, 600 V, 3-pole plug-in molded case circuit breaker with a thermal-magnetic trip unit. It’s engineered to partner with matching OEM panelboards for a seamless, protected electrical system. If you’re wiring dense, multi‑circuit environments and want a breaker you can count on for quick installs and consistent performance, this model ticks the boxes.