Siemens | ED21B040L | Circuit Breaker | 40A | 1-Pole | 120V

Siemens ED21B040L stands as a dependable solution for protecting 120-volt branch circuits with a 40-amp capacity. This 1-pole circuit breaker is engineered for straightforward retrofits, replacements, and maintenance projects where exact specs matter. When it's time to refresh an aging panel or restore safe, code-compliant protection, ED21B040L delivers reliable interruption and reset performance in a compact, screw-terminal design.

Key specifications

• Amperage: 40 A
• Poles: 1-Pole
• Voltage: 120 V

Why choose the Siemens ED21B040L

Ed21b040L is specifically sized to match common 1-pole, 120V circuits. It serves well in retrofit projects where the panel is already configured for Siemens ED-series breakers, ensuring compatibility with existing bus bars and mounting methods. This isn't a generic, one-size-fits-all breaker—it's a precise part that aligns with your panel's design, reducing the guesswork during replacements.

Ideal use cases

• Replacing a failed 40A, single-pole breaker in residential panels for lighting circuits, outlets, or shared branch circuits.
• Retrofit projects where a matching ED-series 40A breaker is required to restore protection without changing the panel's internal layout.
• Maintenance and ongoing reliability in 120V circuits that demand a predictable, quick-reset protection device.

Important compatibility notes

Before you order, confirm fit and ratings against your panel's labeling. The part number is the best reference for compatibility, so verify ED21B040L aligns with your panel model and the 40 A / 1-pole / 120V specification. If the numbers match, you’re choosing a breaker designed to protect the circuit and support safe operation over time.

Installation and safety considerations

• Shutdown power to the panel and follow standard safety practices before handling breakers.
• Ensure the breaker mounts securely to the bus and the terminal torque complies with your panel's requirements (consult a licensed electrician if in doubt).
• Maintain proper labeling for protected circuits after replacement.

With Siemens ED21B040L, you gain a purpose-built, specification-aligned solution that keeps your 120V circuits protected and your panel space optimized. When the time comes for maintenance, retrofit, or straightforward replacement, this 40A, 1-pole option is a reliable, exact-match choice for compatible panels.