Siemens HHJXD63B300 - 300 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens HHJXD63B300 is a rugged, high-capacity bolt-on molded case circuit breaker designed to protect your electrical system with precision. Rated at 300 A and 600 V, this 3-pole unit delivers dependable branch-circuit overcurrent and short-circuit protection for panelboards and loadcenters in demanding environments.

Built for reliability in real-world installations, the bolt-on mounting provides a secure, vibration-resistant bus connection that stays tight even in settings with equipment vibration or cycling loads. The result is consistent protection performance across a wide range of operating conditions.

Key benefits that matter in the field

• Secure bolt-on mounting: Ensures a rigid, long-lasting connection to the bus, reducing the risk of loose contacts and nuisance trips.
• Thermal-magnetic trip unit: Combines precise thermal overload protection with instantaneous magnetic response to shield circuits from both gradual faults and sudden surges.
• Three-pole design: Ideal for three-phase systems common in commercial and light industrial applications, while still suitable for residential setups requiring robust protection.
• High-capacity rating: 300 A at 600 V provides a capable solution for larger branch circuits and higher fault-current scenarios.
• OEM-compatible: Designed to integrate with matching Siemens OEM load centers and panelboards for a streamlined replacement or upgrade.

Why this design makes a difference

In panel installations, the connection integrity between the breaker and the bus is a common source of reliability issues. The HHJXD63B300’s bolt-on approach minimizes movement, reduces wear over time, and sustains protective performance even under vibration or frequent cycling. The thermal-magnetic trip mechanism delivers predictable, repeatable responses—long-time protection against sustained overloads and immediate action on short circuits—so equipment and wiring stay safer with less downtime.

Ideal use cases

• Upgrading service panels in commercial spaces or light industrial facilities where 3-phase protection is required.
• Replacing aging or incompatible breakers in OEM panelboards that require a Siemens bolt-on solution.
• Protecting sizable branch circuits with a single, robust unit capable of handling higher fault currents at once.
• Applications spanning residential, commercial, and light industrial environments where dependable overcurrent protection is essential.

Specifications at a glance

• Manufacturer: Siemens
• Part Number: HHJXD63B300
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 300 A
• Voltage rating: 600 V
• Number of poles: 3
• Mounting style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

For professionals seeking a reliable, installation-friendly protection solution within Siemens’ ecosystem, the HHJXD63B300 from AmpState offers a compelling combination of strength, compatibility, and performance. Bring secure protection to your panelboards and loadcenters—order this 3-pole bolt-on circuit breaker and keep critical circuits safeguarded.