Siemens HHJD63B400 - 400 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Overview

The Siemens HHJD63B400 is a high-capacity 400 A, 600 V, 3-pole bolt-on molded case circuit breaker designed for reliable branch circuit overcurrent and short-circuit protection in panelboards and load centers. Built for demanding residential, commercial, and light industrial environments, this unit delivers consistent protection performance when it’s needed most.

Why it stands out

• Secure bolt-on mounting: A rigid, vibration‑resistant bus connection minimizes movement and arcing, improving long-term reliability in busy electrical rooms.
• Thermal-magnetic trip unit: Combines precise thermal overload protection with rapid magnetic response for dependable trips across varying fault conditions.
• Three-pole protection: Ensures synchronized interruption across all phases in 3‑phase systems, preserving balance and safety.
• OEM-compatible design: Engineered to pair with matching Siemens OEM load centers and panelboards for seamless retrofits or new installations.

Technical specifications

• Manufacturer: Siemens
• Part Number: HHJD63B400
• 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

Ideal applications

Designed for panelboards and load centers that serve three-phase distribution in homes, offices, retail spaces, and light industrial facilities. If you need dependable, balanced protection for multi‑wire circuits and want a solution that performs consistently under vibration and electrical stress, this 3‑pole bolt-on breaker from Siemens is a strong fit.

Installation and reliability tips

• Verify the panelboard or load center is rated for bolt-on breakers and ensure bus connections are clean before mounting.
• Torque mounting hardware to the panel manufacturer’s specifications to preserve the integrity of the bolt-on connection against vibration.
• When possible, align this breaker with other Siemens protection devices to maintain a cohesive and predictable protection strategy across the system.