Square D LRA36400U44X - 400 A, 3-Pole Plug-In Circuit Breaker | AmpState

Protect large electrical feeds with precision using the Square D LRA36400U44X. This 400 A, 3-pole plug-in molded case circuit breaker is engineered for dependable branch circuit overcurrent and short-circuit protection in panelboards and loadcenters. AmpState brings you a thoughtfully designed solution that streamlines installation and reinforces safety in demanding installations.

Key advantages that set this 400 A plug-in breaker apart

• Fast plug-in connection for quick installation and effortless replacement, minimizing downtime during panel servicing or upgrades.
• Thermal-magnetic trip unit delivers stable, repeatable protection by combining a thermal overload element with a magnetic instantaneous trip for severe faults.
• OEM-compatible design built to work with matching Square D loadcenters and panelboards, ensuring reliable fit and predictable performance.
• Versatile application suitable for residential, commercial, and light industrial electrical systems that demand robust, code-compliant protection.

Technical snapshot

• Manufacturer: Square D
• Part Number: LRA36400U44X
• 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

Ideal use cases

• Main feeder protection in sizable panelboards and distributed load centers for commercial buildings.
• Protection for feeders and circuits in light industrial installations where three-phase, high-current protection is required.
• Replacement or upgrade in compatible Square D panels to preserve electrical system continuity and protection standards.

Installation, compatibility, and best practices

To get the most out of the LRA36400U44X, pair it with compatible Square D panelboards and loadcenters designed for plug-in molded case breakers. Before installation, verify that the panel labeling supports a 400 A, 3-pole device and follow the panel manufacturer’s instructions for mounting torque and clearance. This breaker is designed to respond quickly to short circuits while reliably tolerating typical operating loads, helping you avoid nuisance trips and preserve service continuity. If you’re upgrading an aging protection scheme, this unit offers a straightforward path to enhanced fault protection without rewiring or panel modification.

Why AmpState recommends this model

For facilities and systems that demand dependable, high-current protection with minimal downtime, the Square D LRA36400U44X combines fast installation with a robust thermal-magnetic protection profile. Its three-pole configuration supports balanced three-phase protection, making it a practical choice for both new installs and panel replacements in environments where reliability matters most.

Ready to reinforce your electrical protection with a trusted, OEM-aligned solution? The Square D LRA36400U44X from AmpState delivers precise protection, compatibility, and ease of use in one durable package.