Siemens JXD63L400 - 400 A, 480 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Meet the Siemens JXD63L400 — a rugged, high-capacity bolt-on molded case circuit breaker designed to protect large branch circuits in panelboards and loadcenters. At 400A and 480V, this 3-pole unit delivers reliable, fast-acting protection for demanding commercial and light-industrial electrical environments, while integrating smoothly with OEM loadcenters for a seamless upgrade or replacement.

Why this breaker stands out

• Secure bolt-on mounting: Provides a rigid, vibration-resistant bus connection that stays tight under operating conditions, reducing the risk of connection loosening in busy electrical rooms.
• Thermal-magnetic trip unit: Combines instantaneous short-circuit protection with time-delayed overload protection for stable, repeatable performance across varying load profiles.
• 3-pole design for 3-phase systems: Specifically suited for 3-phase circuits common in commercial and light-industrial applications, ensuring balanced protection across all phases.
• OEM compatibility: Engineered to pair with matching Siemens OEM loadcenters and panelboards, simplifying replacements, retrofits, and panel upgrades.
• Versatile application: Ideal for residential, commercial, and light-industrial electrical installations where robust branch-circuit protection is required.

Technical specifications at a glance

• Manufacturer: Siemens
• Part Number: JXD63L400
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400A
• Voltage Rating: 480V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use cases

• Upgrading or replenishing large panelboards and loadcenters that serve 3-phase commercial equipment.
• Protecting heavy-load feeders in light-industrial rooms, equipment closets, and electrical rooms with vibration-prone environments.
• Retrofits and new installations where a secure bolt-on connection minimizes movement and ensures consistent electrical contact.

Installation and compatibility guidance

The JXD63L400 is designed to slot into Siemens-compatible panelboards and loadcenters that support bolt-on molded case breakers. When installing, ensure the panelboard or loadcenter is specified for bolt-on MCCBs of this size and verify that the 3-pole configuration aligns with your 3-phase electrical system. This unit’s bolt-on mounting provides a dependable bus connection that remains steady through thermal cycling and routine vibrations common in commercial spaces.

Practical tips for best results

• Confirm that your panelboard or loadcenter is compatible with Siemens JXD63L400 bolt-on breakers to ensure electrical and mechanical compatibility.
• During installation, secure all mounting hardware to maintain the integrity of the bus connection and minimize resistance points.
• Use this breaker in applications where a robust, reliable thermal-magnetic protection is required for high-current 3-phase circuits.

The Siemens JXD63L400 delivers a focused, purpose-built solution for safeguarding substantial 3-phase circuits. With its secure mounting, dependable trip mechanism, and OEM-compatible design, it’s a practical, long-term choice for reliable electrical protection in panelboards and loadcenters.