Siemens HJXD63B400H - 400 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens HJXD63B400H is a 400A, 600V, 3-pole bolt-on molded case circuit breaker engineered to deliver dependable branch circuit overcurrent and short-circuit protection in panelboards and load centers. With a secure bolt-on mounting and a thermal-magnetic trip unit, this device provides stable, repeatable protection in demanding environments—from residential distribution to commercial and light industrial applications.

What sets this breaker apart

• Secure bolt-on mounting for a rigid, vibration-resistant bus connection that stays aligned under dynamic conditions—reducing the risk of loose connections and nuisance trips.
• Thermal-magnetic trip unit combines time-delayed thermal protection with instantaneous magnetic trip for reliable response to both overloads and short circuits.
• OEM panel compatibility designed to pair with matching Siemens OEM loadcenters and panelboards, ensuring seamless fit and consistent performance.
• High-current, high-voltage capability suited for large circuits in residential, commercial, and light industrial settings—400A at 600V protects substantial feeder and distribution circuits.

Technical snapshot

• Manufacturer: Siemens
• Part Number: HJXD63B400H
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400A
• Voltage Rating: 600V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection in panelboards/load centers

Ideal applications and use cases

• Protection for large feeder circuits in residential service panels or multi-breaker distribution boards where 3-phase loads require solid overcurrent protection.
• Main or sub-feed protection in commercial panelboards handling significant equipment, HVAC, or lighting loads.
• Reliable protection for light industrial circuits that demand robust, vibration-resistant connections and precise interruption of fault currents.

Why choose this Siemens breaker over alternatives

• The bolt-on design delivers a sturdier, vibration-resilient connection, reducing maintenance concerns in installations subject to movement or mechanical stress.
• The thermal-magnetic trip unit provides predictable, repeatable protection curves across temperature ranges, helping prevent nuisance trips while guarding against sustained faults.
• Designed to integrate with Siemens OEM load centers and panelboards, offering cohesive performance, documented compatibility, and simpler replacement decisions.

Installation and practical considerations

• Before installation, verify the breaker’s compatibility with the specific Siemens panelboard or load center model in use to ensure correct bus routing and mounting alignment.
• Follow manufacturer torque specs for bolt-on mounting to maintain a solid electrical and mechanical connection and to preserve the integrity of the bus bar interface.
• Use this 3-pole breaker for branch circuit protection where a 400A maximum device is appropriate, and ensure conductors and overcurrent protection devices upstream are sized accordingly.
• Consider this unit for upgrading existing high-current circuits that require a reliable, heavy-duty bolt-on solution with clear, repeatable trip behavior.

With the Siemens HJXD63B400H, you’re choosing a high-capacity, dependable protective device designed to keep large, essential circuits safe in the real world—from home autos and workshops to busy commercial spaces. Its combination of secure mounting, precise thermal-magnetic protection, and OEM-friendly compatibility makes it a practical, future-ready choice for robust electrical panel protection.