Siemens HHJD63B400L - 400 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens HHJD63B400L is a 400 A, 600 V, 3-pole bolt-on molded case circuit breaker designed to protect panelboards and loadcenters from overcurrent and short-circuit faults with reliability and ease of maintenance.

Engineered for challenging electrical environments, its secure bolt-on mounting provides a rigid, vibration-resistant bus connection, helping maintain a solid mechanical link even in installations subject to movement or vibration. This solid connection minimizes contact resistance fluctuations that can compromise performance over time.

The built-in thermal-magnetic trip unit delivers stable, repeatable protection: the magnetic element responsive to high fault currents rapidly disengages the circuit during short circuits, while the thermal element guards against sustained overloads. The result is safer equipment operation, reduced downtime, and longer life for wiring and connected devices.

Designed for compatibility, the HHJD63B400L works with matching Siemens OEM load centers and panelboards, ensuring a seamless fit and dependable coordination with other protective devices in your electrical distribution system.

Why this matters for your project

For residential, commercial, and light industrial applications, this 3-pole breaker provides robust three-phase protection where it’s needed most. It’s ideal for upgrading existing panels, replacing worn breakers, or configuring new installations that demand reliable, code-compliant overcurrent protection across three phase conductors.

Key features

• Bolt-on mounting for a secure, vibration-resistant bus connection.
• Thermal-magnetic trip delivers stable overload and fast short-circuit disconnection.
• 3-pole, 400 A, 600 V rating suits medium to high-demand circuits.
• Siemens OEM compatibility with matching load centers and panelboards.
• Versatile applications suited for residential, commercial, and light industrial environments.

Technical specifications

• Manufacturer: Siemens
• Part Number: HHJD63B400L
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 400 A
• Voltage Rating: 600 V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Whether you’re upgrading a panel, configuring a new electrical rack, or safeguarding critical loads, the Siemens HHJD63B400L delivers dependable protection with a design that prioritizes secure mounting, precise trip performance, and long-term reliability in everyday electrical infrastructure.