Siemens LGB3B020B - 20 A, 480 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Introducing the Siemens LGB3B020B, a 20A, 480V, 3-pole bolt-on molded case circuit breaker engineered for dependable branch circuit protection in panelboards and load centers. Designed for consistent performance in demanding environments, this unit combines secure mounting with precise protection characteristics to keep electrical systems safe and reliable.

• Rigid bolt-on mounting delivers a secure, vibration-resistant connection to the bus, reducing movement and ensuring stable electrical contact in panels with machinery or dynamic loads.
• Thermal-magnetic trip unit provides stable, repeatable protection by quickly responding to both overloads and short circuits, helping to prevent equipment damage and downtime.
• Three-pole design for 480V systems perfectly suited for 3-phase applications common in commercial and light industrial environments.
• OEM-compatible fit is designed to work with matching Siemens OEM load centers and panelboards, facilitating straightforward replacement or upgrade without layout changes.
• 20A branch-circuit protection ideal for distributing reliable current to multiple devices, motors, and control circuits while maintaining safe operation.

Technical snapshot

• Manufacturer: Siemens
• Part Number: LGB3B020B
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 20A
• Voltage Rating: 480V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use cases

This 3-pole, 480V breaker is a robust choice for commercial and light industrial electrical distributions. Use it in panelboards and load centers that serve three-phase equipment, HVAC controls, lighting panels, or motor-control centers where vibration resistance and reliable trip performance matter. It’s particularly well-suited for installations where a bolt-on solution provides a sturdier connection than plug-in alternatives, reducing the risk of loose bus contacts in high-load or vibration-prone environments.

Why choose the Siemens LGB3B020B

• Unique bolt-on design that minimizes movement and improves contact integrity in challenging installations.
• Thermal-magnetic protection delivers predictable breaker behavior, helping technicians plan and protect downstream equipment with confidence.
• OEM-compatible architecture means fewer compatibility concerns when upgrading or maintaining Siemens panelboards and load centers.
• Specifically built for 480V three-phase circuits, aligning with common commercial and light-industrial power distribution needs.

Practical tips for installation and use

• Verify that your panelboard or load center is designed for bolt-on breakers in the LGB family to ensure a proper mechanical and electrical fit.
• When replacing an existing device, confirm that the replacement’s trip characteristics align with the protected load’s electrical profile to avoid nuisance trips.
• Keep the 480V rating in mind when planning central distribution to motors and three-phase equipment; wire sizing and protective device coordination should reflect this voltage tier.
• Store and handle the breaker carefully to preserve the integrity of the thermal-magnetic trip mechanism for long-term reliability.

With the Siemens LGB3B020B, you gain a disciplined, durable solution for protecting critical three-phase loads. It’s a purpose-built choice for professionals who demand consistent trip performance, solid mechanical mounting, and seamless integration with Siemens panel products.