Siemens | E21B100 | Circuit Breaker | 100A | 1-Pole | 120V | Bolt-On

Introducing the Siemens E21B100 Circuit Breaker — a purpose-built, high-current protection device designed for reliable performance in compatible panels. With a 100-amp rating, a single pole, and 120-volt operation, this bolt-on breaker delivers robust, predictable protection for demanding circuits while preserving space in the panelboard.

Designed for maintenance, retrofit, and replacement projects, the E21B100 shines in scenarios where you need to match exact specs quickly and confidently. The model number E21B100 is your best reference for compatibility, ensuring a secure fit in Siemens bolt-on panel systems.

Key specifications

• Amperage: 100 A — ideal for high-demand branch circuits such as heavy appliances, HVAC equipment, or subfeed connections in residential or light commercial setups.
• Poles: 1-Pole — compact single-pole protection for 120V circuits.
• Voltage: 120V — designed for standard residential/commercial distribution panels.
• Mounting: Bolt-On — provides a secure, mechanical connection to the bus bar in compatible Siemens panels, reducing the risk of loose contacts.
• Part Number: E21B100 — use this reference to confirm fit and ratings with your panel label or manufacturer documentation.

What sets this Siemens breaker apart

• Direct compatibility with Siemens bolt-on panel systems, enabling straightforward retrofits without modifying the enclosure.
• Reliable overload protection for circuits with higher current demands, helping to prevent electrical fires and equipment damage.
• Durable construction designed for repeated cycling and long service life in demanding environments.

Ideal use scenarios

• Replacing a failed 100A, 1-pole breaker in a Siemens panel where bolt-on mounting is required.
• Retrofits that require exact 100A, 1-pole, 120V specifications to support high-demand loads.
• New installations within compatible service panels where 100A protection is appropriate for a dedicated circuit (e.g., large appliances, water heaters, or HVAC components).

Installation notes

Before ordering, confirm fit and ratings for your exact panel model. The part number E21B100 is the most reliable reference for compatibility. When installing, follow standard electrical safety practices: turn off the main power, verify the absence of voltage, and secure the breaker firmly to the bus with the bolt-on hardware specified by Siemens for this product.