Siemens JD63B300L - 300 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens JD63B300L is a robust 300A, 600V, 3‑pole bolt‑on molded‑case circuit breaker designed to safeguard your electrical distribution. Built for dependable branch circuit overcurrent and short‑circuit protection in panelboards and loadcenters, it delivers reliable performance where it matters most. Available through AmpState for dependable sourcing and fast fulfillment.

Key advantages you’ll notice in real‑world panels:

• Secure bolt‑on mounting provides a rigid, vibration‑resistant bus connection that stays tight over time, reducing nuisance trips from loose connections.
• Thermal‑magnetic trip unit delivers stable, repeatable protection by reacting to both overload (thermal) and short‑circuit (magnetic) conditions.
• OEM compatibility designed to pair with matching Siemens OEM load centers and panelboards for a streamlined, integrated protection system.
• Versatile application suitable for residential, commercial, and light industrial environments where dependable feeder protection is essential.

Technical specifications

• Manufacturer: Siemens
• Part Number: JD63B300L
• Type: Thermal‑magnetic molded case circuit breaker
• Amperage rating: 300 A
• Voltage rating: 600 V
• Number of poles: 3
• Mounting style: Bolt‑on
• Primary use: Branch circuit overcurrent and short‑circuit protection

Use scenarios and practical tips:

• Install in service panelboards or distribution panels to protect feeders feeding subpanels, motor circuits, and lighting mains in commercial spaces or light industrial facilities.
• When replacing an aging breaker or expanding capacity, JD63B300L ensures compatibility with Siemens panel hardware, reducing retrofit complexity.
• Ensure proper torque on mounting bolts per manufacturer guidelines to maintain that vibration‑resistant connection in areas with equipment or HVAC loads.