Siemens LGB3B100B - 100 A, 600 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens LGB3B100B is a 3-pole bolt-on molded case circuit breaker engineered for dependable branch-circuit protection in panelboards and load centers. With a 100A rating and a 600V capacity, this unit is built to handle robust 3-phase distribution while delivering consistent protection across residential, commercial, and light industrial installations.

• Secure bolt-on mounting provides a rigid bus connection and resists vibration, reducing loosening and improving long-term reliability in panels and equipment racks.
• Thermal-magnetic trip unit delivers stable, repeatable protection: the thermal element guards against nuisance overloads, while the magnetic element responds quickly to short circuits to minimize damage.
• OEM panel compatibility is designed to match Siemens load centers and panelboards, ensuring a smooth, plug-and-play replacement or expansion without compatibility concerns.
• 3-pole design supports 3-phase circuits up to 600V, making it suitable for commercial and light industrial feeders as well as multi‑phase residential setups that require reliable 3‑phase protection.
• Durable construction built for steady performance in environments where vibration, switching, and electrical transients are common.

Technical specifications

• Manufacturer: Siemens
• Part Number: LGB3B100B
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 100A
• Voltage Rating: 600V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal applications and use cases

Designed for professionals who need reliable protection in panel enclosures, the LGB3B100B is well-suited for:

• Residential and light commercial panel upgrades where 3-phase protection is required
• Commercial distribution panels and service panels that demand secure, vibration-resistant mounting
• New installations in dashboard or equipment rooms where robust short-circuit protection is essential
• Replacement in Siemens OEM load centers to maintain consistent performance and compatibility

Practical guidance for use

To maximize performance and safety, install the LGB3B100B in compatible Siemens panelboards and load centers, ensuring the overall panel rating supports 100A, 3-pole protection. Follow standard electrical codes for bolt-on mounting procedures, and verify that wiring and conductors are rated for up to 600V and the intended amperage. This breaker is ideal for systems where steady protection against overcurrent and short circuits is critical, such as feeder lines, motor circuits, and essential service panels in light industrial settings.

Why choose this Siemens breaker

The LGB3B100B combines a secure bolt-on installation with a proven thermal-magnetic trip mechanism and OEM-panel compatibility, delivering precise, reliable protection in a compact, durable package. It’s a purpose-built solution for professionals who value straightforward installation, predictable protection curves, and long-term panel reliability.