Siemens HJM3M400 400A 3P 600V Circuit Breaker, Bolt-On | AmpState

Meet the Siemens HJM3M400 — a robust 400 A, 3-pole, 600 V bolt-on circuit breaker designed to shield panelboards, load centers, and electrical distribution systems from overloads. Built for everyday electrical work, it’s an ideal choice for replacement projects and stocking spares to keep your bill of materials (BOM) in line with the original part number.

Why the HJM3M400 stands out in practical installations:

• Bolt-On mounting provides a secure, fast-to-install solution that stays put in busy electrical environments.
• 400 A capacity with a 3-pole configuration delivers reliable three-phase protection for demanding commercial or industrial circuits.
• 600 V rating supports a wide range of distribution setups, making it suitable for many standard electrical distributions.
• Original-part alignment helps you maintain BOM integrity during repairs or upgrades, reducing confusion and rework.
• Replacement-ready design means fewer compatibility concerns when restoring systems to spec after outages or maintenance.

Ideal applications and use cases

Use the HJM3M400 in panelboards and load centers where three-phase protection is required, such as commercial electrical rooms, industrial distribution panels, and service equipment with a need for dependable, field-replaceable protection devices. It’s especially advantageous when you’re:

• Performing a targeted replacement to restore original protection levels without altering the BOM.
• Stocking spares for quick, on-site swaps to minimize downtime.
• Maintaining alignment with the original Siemens part number during system upgrades or reconfigurations.

Specifications at a glance

• Manufacturer: Siemens
• Part number: HJM3M400
• Type: Circuit Breaker
• Amperage rating: 400 A
• Poles: 3
• Voltage rating: 600 V
• Mounting: Bolt-On

Need help confirming fit?

Choosing the right part can feel routine until compatibility matters. If you’re unsure whether the HJM3M400 matches your panelboard, load center, or distribution setup, AmpState is ready to assist. Message us to verify compatibility and ensure a seamless replacement that preserves system safety and performance.