Siemens BQD120 20A 1P 277V Circuit Breaker, Bolt-On | AmpState

Meet the Siemens BQD120 — a bolt-on, 20A, 1-pole circuit breaker designed for panelboards, load centers, and electrical distribution. Its retrofit-friendly bolt-on design supports maintenance planning when the part number needs to stay consistent, while a 277V rating makes it a practical choice for commercial circuits and lighting feeders in mid-size facilities. The BQD120 is built to protect a single branch with reliable overcurrent protection, helping you maintain safe and uninterrupted power delivery.

Why the Siemens BQD120 stands out

• Bolt-on mounting provides a secure, robust fit in panelboards and load centers, simplifying retrofit work and reducing field installation time.
• 277V rating aligns with typical commercial electrical distribution, so you can protect higher-voltage branches without adapters or workarounds.
• 1-pole, 20A configuration offers targeted protection for individual circuits, keeping your distribution system simple and easy to manage.
• Part-number continuity supports maintenance planning and inventory control — use BQD120 to match existing protection schemes without surprises.
• AmpState availability ensures timely access and expert support to confirm compatibility and fit for your system.

Key specifications

• Manufacturer: Siemens
• Part Number: BQD120
• Type: Circuit Breaker
• Amperage: 20 A
• Poles: 1
• Voltage: 277 V

Ideal use cases

• Retrofit installations in panelboards and load centers where a bolt-on device is preferred for secure mounting and quick swaps.
• Protection of 277V circuits in commercial buildings, including lighting feeders and auxiliary power branches.
• Maintenance planning episodes requiring consistent part numbers to minimize inventory fragmentation.
• New or replacement installs in facilities that rely on Siemens protection components for long-term reliability.

Installation and practical considerations

Before you select the BQD120, verify your panel supports bolt-on breakers and that the mounting hardware is compatible with Siemens’ installation guidelines. Follow standard electrical safety practices, de-energize equipment, and adhere to local codes during replacement or retrofit work. The 277V rating should match the circuit it protects, ensuring proper protection without oversizing or undersizing the breaker.

Support and availability

AmpState lists the BQD120 as available, with expert assistance to confirm fit and compatibility when you’re upgrading existing panels or planning a retrofit. If you’re matching a part number for a specific installation, reach out for guidance and we’ll help ensure the BQD120 is the right choice for your Siemens-based protection scheme.