Square D MJA36500 - 500 A, 600 V, 3-Pole Plug-In Circuit Breaker | AmpState

Square D MJA36500 is a high-capacity, plug-in molded case circuit breaker designed to deliver reliable branch circuit protection in panelboards and load centers. With a robust 500A rating, 600V capacity, and a 3-pole configuration, it’s engineered to handle demanding electrical environments with ease.

• Fast plug-in connection: Quick installation and easy replacement, minimizing downtime during panel maintenance or upgrades.
• Thermal-magnetic trip unit: Delivers stable, repeatable protection against overloads and short circuits, helping to prevent nuisance tripping and ensuring consistent performance over time.
• Three-pole design: Ideal for three-phase systems found in commercial and light industrial applications, providing coordinated protection across all phases.
• 600V rating: Suitable for higher-voltage distribution tasks within panelboards and load centers, supporting safer and more versatile electrical setups.
• OEM-compatible: Designed to be compatible with matching Square D OEM load centers and panelboards for seamless integration and reliable operation.
• Versatile applications: Suitable for residential, commercial, and light industrial environments where dependable overcurrent and short-circuit protection is essential.

Technical specifications at a glance

• Manufacturer: Square D
• Part number: MJA36500
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 500A
• Voltage rating: 600V
• Number of poles: 3
• Mounting style: Plug-in
• Application: Branch circuit overcurrent and short-circuit protection

Use cases and ideal applications

• Commercial electrical rooms and service panels needing robust, high-current protection for 3-phase distribution.
• Light industrial setups where rapid replacement and minimized downtime are priorities due to plug-in installation.
• Residential-to-light-commercial panel upgrades that require OEM-compatible components for reliable performance.
• Systems requiring consistent trip characteristics to maintain protection coordination across multiple circuits.

Why this breaker stands out

The MJA36500 combines a dependable thermal-magnetic protection scheme with a plug-in design that reduces installation time and service intervals. Its compatibility with matching OEM panels ensures a smooth, trouble-free retrofit or expansion, while the three-pole construction supports balanced protection across all phases in three-phase systems. For facilities that value uptime and predictable protection, this Square D breaker provides a clear, practical advantage over generic alternatives.

Practical installation and care tips

• Confirm panelboard compatibility with the MJA series before installation to ensure optimal fit and electrical performance.
• Use the plug-in connection to minimize on-site wiring complexity during replacement or expansion projects.
• Handle with care during removal and replacement to preserve bus connections and prevent contamination of the interior of the panel.
• Regularly inspect for signs of wear or heat on the breaker and surrounding components as part of routine electrical maintenance.