Siemens ED43B125 125A 3P 480V Circuit Breaker, Bolt-On | AmpState

Meet the Siemens ED43B125: a 125 A, 3-pole, 480 V bolt-on circuit breaker designed to deliver reliable protection in panelboards, load centers, and broader electrical distribution systems. This unit is a precise part-number match that streamlines procurement and field replacements, making it a smart choice for maintenance teams and panel builders who value consistency and traceability.

Why this breaker stands out: it combines Siemens' robust engineering with a bolt-on mounting style that simplifies installation and improves mechanical stability in demanding environments. The 125-amp rating provides strong protection for feeders and circuits in 480 V networks, while the 3-pole configuration supports balanced, coordinated protection across three phases.

• Part Number: ED43B125
• Type: Bolt-On circuit breaker
• Amperage: 125 A
• Poles: 3
• Voltage: 480 V
• Applications: panelboards, load centers, electrical distribution

This device is ideal for teams maintaining critical infrastructure where exact compatibility matters. Storing this exact ED43B125 part reduces the risk of incorrect replacements, short windows of downtime, and procurement headaches. It’s a dependable option for projects and service calls that demand consistent, repeatable performance from a trusted manufacturer.

Practical use cases include upgrading or stocking spare breakers in industrial control panels, retrofitting legacy 480 V distribution boards, or provisioning new builds with a reliable Siemens bolt-on solution that aligns with existing Siemens components.

How it compares to ad hoc replacements—this ED43B125 is built for compatibility with Siemens panel systems, ensuring fit and electrical characteristics align with your existing setup, which helps you avoid mismatch risks that can complicate inspections or future maintenance.

Installation and care tips:

• Ensure the receiving panel is compatible with bolt-on breakers of the ED43 series.
• Verify your system operates at 480 V and that three-phase connections correspond to the three poles.
• Confirm the exact part number (ED43B125) to guarantee a direct fit with your panel’s bus and enclosure.
• When in doubt about fit, AmpState offers assistance to confirm compatibility before purchase.

Availability—AmpState has this Siemens ED43B125 125A 3P 480V bolt-on circuit breaker in stock. Need help matching a part number or confirming compatibility? Message us and we’ll help you confirm fit.