Siemens ED21B040L - 40 A, 120 V, 1-Pole Bolt-On Circuit Breaker | AmpState

Siemens ED21B040L is a rugged 40A, 120V, 1-pole bolt-on molded case circuit breaker engineered for dependable branch circuit protection in panelboards and loadcenters. This unit delivers reliable overcurrent and short-circuit protection for residential, commercial, and light industrial electrical setups, making it a solid choice for upgrades, retrofits, or new installations.

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, reducing loosening risks in environments with movement or vibration.
• Thermal-magnetic trip unit combines precise thermal overload sensing with instantaneous magnetic trip for fast, repeatable protection against both gradual overheating and sudden fault conditions.
• Plug-free reliability designed for use with matching OEM Siemens loadcenters and panelboards, ensuring proper fit and predictable performance within your system.
• Versatile, all-purpose protection suitable for a wide range of applications—from lighting and receptacle circuits to HVAC and small equipment feeders—without compromising safety.
• Durable molded-case construction built to withstand daily electrical demand and maintain consistent protection over time.

Ideal use cases

• Residential panel upgrades where a dedicated 40A, 120V protection device is required for branch circuits.
• Commercial settings needing reliable protection for lighting, outlets, or small equipment feeders in loadcenters.
• Light industrial applications with vibration or movement where a secure bolt-on connection minimizes nuisance trips and loosening.
• New installations or retrofits that call for Siemens-approved compatibility with OEM panelboards and modular breakers.

What problems does this solve?

• Prevents fire hazards and equipment damage by swiftly interrupting fault currents and preventing overheated conductors.
• Reduces maintenance concerns in installations subject to vibration or mechanical stress due to its secure mounting.
• Provides predictable, repeatable protection—so you can design circuits with confidence and coordination.

Technical snapshot

• Manufacturer: Siemens
• Part number: ED21B040L
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 40A
• Voltage rating: 120V
• Number of poles: 1
• Mounting style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Choose this Siemens ED21B040L for a dependable, OEM-compatible protection solution that pairs robust physical mounting with precise electrical protection. Available from AmpState for straightforward procurement and confident performance in your panelboards and loadcenters.