Siemens MXD63B500 - 500 A, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens MXD63B500 is a heavy-duty 500 A, 3-pole bolt-on molded case circuit breaker engineered for dependable branch circuit overcurrent and short-circuit protection in panelboards and load centers. Built for reliability in demanding electrical environments, this device combines rugged mounting with precise protection to keep systems safe and operational.

Why this breaker stands out for real-world installations

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection that stays tight under real-world conditions, reducing wear and maintaining consistent electrical performance.
• Thermal-magnetic trip unit delivers stable, repeatable protection by responding appropriately to both sustained overloads and sudden short circuits, helping minimize nuisance trips and downtime.
• High-current capability with a 500 A rating is ideal for main feeders or heavy-duty sub-feed protection in larger residential, commercial, and light industrial panels.
• OEM-compatible design is made to integrate smoothly with matching Siemens load centers and other compatible panelboards, ensuring a clean, unified protection solution.
• Three-pole configuration supports 3-phase systems or common-trip protection for three conductors, simplifying wiring and safety compliance in three-phase layouts.

Technical snapshot

• Manufacturer: Siemens
• Part Number: MXD63B500
• Type: Thermal-magnetic molded case circuit breaker (MCCB)
• Amperage: 500 A
• Poles: 3
• Mounting style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use scenarios

• Main feeders in residential developments where a robust, single-point protection is required for upgraded electrical services
• Commercial spaces with high-current 3-phase circuits needing reliable protection to keep lights, HVAC, and equipment running smoothly
• Light industrial panels that demand strong, vibration-resistant connections and precise trip coordination

Practical guidance for optimal performance

• Pair this breaker with Siemens OEM load centers or compatible panelboards to ensure coordinated protection and consistent electrical characteristics.
• Verify panel compatibility and torque requirements during installation to maximize the durability of the bolt-on connection.
• Consider the thermal-magnetic trip behavior in your environment—its stable response helps prevent unnecessary trips in area with fluctuating loads.