Siemens BQ3B09000S01 - 90 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Meet the Siemens BQ3B09000S01—a 90A, 240V, 3-pole bolt-on molded case circuit breaker engineered to deliver dependable branch circuit overcurrent and short-circuit protection in panelboards and load centers. Built to withstand the rigors of real-world electrical systems, it stays secure and reliable under vibration and routine maintenance cycles.

What sets it apart

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, helping maintain consistent electrical performance even in demanding installations.
• Thermal-magnetic trip unit delivers stable, repeatable protection across varying load conditions, responding quickly to short circuits while minimizing nuisance trips on normal motor inrush.
• 3-pole, 90A at 240V design is ideal for 3-phase distribution and feeders, delivering precise protection for commercial and light industrial circuits.
• OEM-compatible works seamlessly with matching Siemens OEM load centers and panelboards, simplifying replacement and upgrades without sacrificing performance.
• Versatile application suited for residential, commercial, and light industrial environments, from emergency feeders to motor-driven equipment protection.

Ideal use cases

• Upgrading existing Siemens panelboards or load centers to enhance branch-circuit protection for 3-phase feeders.
• Protecting feeders that power motors, HVAC equipment, compressors, pumps, and other three-phase loads in light industrial settings.
• New installations requiring a robust 3-pole breaker with reliable thermal-magnetic protection and secure mounting.

Technical snapshot

• Manufacturer: Siemens
• Part Number: BQ3B09000S01
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 90 A
• Voltage Rating: 240 V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Applications: Branch circuit overcurrent and short-circuit protection in panelboards and load centers

Practical guidance for best results

• Ensure the unit is paired with compatible Siemens OEM panelboards or load centers to maintain listing and performance integrity.
• Utilize the secure bolt-on mounting to achieve a rigid connection and minimize vibration-related wear over time.
• Consider the 90A rating when sizing feeders and downstream conductors to optimize protection without unnecessary interruptions.
• In environments with frequent inrush or motor start-ups, the thermal-magnetic trip helps balance protection with operational reliability, reducing nuisance trips.