Siemens BQ3B100 - 100 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Siemens BQ3B100 delivers dependable overcurrent and short-circuit protection for branch circuits in panelboards and load centers. This 100A, 240V, 3-pole bolt-on molded-case circuit breaker is engineered to plug into compatible Siemens and OEM panels, providing a secure, maintenance-friendly solution for demanding electrical environments.

Built for resilience, the bolt-on mounting creates a rigid, vibration-resistant bus connection that stays tight even in installations subject to movement or vibration. The thermal-magnetic trip unit offers stable, repeatable protection by accurately sensing overloads and swiftly clearing faults, helping prevent damage to wiring and connected equipment while minimizing nuisance trips.

Designed for broad compatibility, this unit is intended to work with matching OEM load centers and Siemens panels, ensuring a precise fit, consistent electrical performance, and simpler panel maintenance over time.

Ideal for residential upgrades, commercial applications, and light industrial panels where reliable protection and long-term reliability matter, the BQ3B100 combines robust construction with straightforward installation in a compact form factor.

Key features

• Bolt-on mounting for a secure, vibration-resistant bus connection
• Thermal-magnetic trip for stable, repeatable overcurrent and short-circuit protection
• 100A, 240V, 3-pole configuration designed for three-conductor circuits
• Molded-case construction provides durable, modular protection
• OEM-compatible with Siemens panels and matching load centers

Technical specifications

• Manufacturer: Siemens
• Part Number: BQ3B100
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 100 A
• Voltage Rating: 240 V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Use cases and practical insights

Who benefits most: electricians and facilities managers upgrading or expanding panelboards in homes, small-to-medium commercial spaces, or light-industrial environments where reliability and panel integrity are critical.

• Residential panel retrofits can leverage the secure bolt-on design to maintain solid electrical connections as circuits are added or rearranged.
• Commercial service panels for lighting, receptacle branches, and HVAC feeders gain enhanced protection with a durable, code-compliant MCCB option.
• Light industrial panels that endure higher vibration or movement benefit from the rugged bus connection and repeatable trip performance.

Installation and maintenance tips: confirm the panelboard accepts bolt-on molded-case breakers of the BQ3B100 family, and refer to the panel’s installation guide for torque guidelines and clearance requirements. Periodic inspections should include checking that bolt-on connections remain tight and that the trip mechanism moves freely, ensuring ongoing, reliable protection for your electrical system.