Siemens BQ3B045 - 45 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

The Siemens BQ3B045 is a 45A, 240V, 3-pole bolt-on molded case circuit breaker designed to deliver dependable branch-circuit overcurrent and short-circuit protection in panelboards and load centers. Built for reliability in demanding electrical environments, this breaker provides a solid, vibration-resistant connection that helps maintain consistent protection performance over time.

• Secure bolt-on mounting: a rigid bus connection minimizes movement and arcing, promoting long-term reliability in active panels.
• Thermal-magnetic trip unit: combines precise thermal overload sensing with rapid magnetic response for fast, repeatable protection against overloads and short circuits.
• OEM-compatible design: engineered to work seamlessly with matching Siemens OEM load centers and panelboards, ensuring a cohesive protection system.
• Versatile applications: suitable for residential, commercial, and light industrial electrical installations where 3-pole 240V protection is required.
• Three-pole, 240V operation: ideal for 3-phase systems or multi-wire configurations demanding balanced protection across all phases.

Technical specifications

• Manufacturer: Siemens
• Part Number: BQ3B045
• Type: Thermal-magnetic molded case circuit breaker (MCCB)
• Amperage Rating: 45A
• Voltage Rating: 240V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Who benefits from the Siemens BQ3B045

Industrial technicians and electrical contractors working on panel installations, retrofit projects, or service upgrades will appreciate the bolt-on reliability and compatibility with Siemens panel ecosystems. It’s a solid choice for new builds or enhancements in spaces like small offices, retail spaces, light manufacturing, or residential-commercial hybrids where robust 240V 3-pole protection is essential.

Practical usage scenarios

• Adding dependable 3-phase protection to a new Siemens panelboard in a small commercial setting.
• Upgrading an existing load center to support balanced 3-pole 240V circuits with a stable trip mechanism.
• Providing dedicated protection for 45A feeder circuits feeding motor loads or other 240V equipment in light industrial environments.

With the Siemens BQ3B045, you get a purpose-built, bolt-on solution that prioritizes secure installation, consistent protection, and seamless compatibility within Siemens’ panelboard ecosystem. It’s a focused, reliable choice when you need solid 3-pole protection at 240V without compromise.