Siemens | E42B040 | Circuit Breaker | 2-Pole | 18kA | Bolt-On

Meet the Siemens E42B040, a dependable 2-pole bolt-on circuit breaker designed to protect commercial and industrial electrical systems. Built for maintenance, retrofit, and replacement projects, this unit delivers reliable overcurrent protection while maintaining compatibility with Siemens panel environments.

Siemens E42B040 — 2-Pole Bolt-On Circuit Breaker

Designed for continuity and ease of service, the E42B040 combines a robust bolt-on mounting with a precise 18kA interrupting capacity. When your panel requires a Siemens-qualified component with exact specifications, this breaker delivers the dependable performance you expect from Siemens equipment.

Key specifications

• Poles: 2-Pole
• Interrupting rating: 18 kA
• Mounting: Bolt-On
• Part number: E42B040

What makes this breaker stand out

• Secure bolt-on mounting: Provides a rugged, vibration-resistant installation ideal for industrial environments and retrofit projects where panel integrity matters.
• High interrupting capacity: 18kA rating supports protection for circuits with significant fault currents, helping to minimize damage and downtime.
• Siemens-only compatibility: The E42B040 is designed to align with Siemens panel architectures, ensuring reliable tripping performance and electrical coordination.
• Clear fit reference: The part number is the best reference for compatibility—always verify fit and ratings before ordering to avoid mismatches.

Ideal applications and use cases

• Maintenance and retrofits in existing Siemens-controlled panels where a precise two-pole, 18kA breaker is required.
• Replacement of worn or outdated breakers in commercial buildings, factories, or data centers that demand dependable protection and easy field service.
• New installations that mirror Siemens specifications, ensuring consistent performance and electrical coordination with other Siemens components.

Installation and best practices

For optimal results, ensure the panel labeling matches the E42B040’s specifications and that the installation is performed by a qualified professional. Before ordering, confirm the fit and ratings align with your panel’s requirements, and follow standard bolt-on torque guidelines to secure the breaker firmly in place. Keeping a precise record of the part number (E42B040) helps streamline future maintenance and replacements.