Siemens Q120DF 20A 1P 120V Circuit Breaker, AFCI, GFCI, Dual-Function, Plug-On | AmpState

Meet the Siemens Q120DF 20A 1P 120V dual-function circuit breaker—AFCI and GFCI combined in a single plug-on device. This 1-pole breaker is purpose-built for panelboards and load centers, delivering advanced protection where it matters most. Ideal for retrofit projects and maintenance planning, the Q120DF helps you keep part numbers consistent while upgrading safety features in existing electrical systems.

What makes the Q120DF stand out

• Dual-function protection—combines AFCI (arc-fault) and GFCI (ground-fault) functionalities in one compact breaker, meeting modern electrical codes without layering multiple devices.
• 20A, 1P, 120V configuration—perfect for standard 120-volt circuits such as general lighting, outlets, or dedicated lighting branches in homes and small offices.
• Plug-on design—quick, tool-free installation that snaps into compatible Siemens panelboards and load centers, reducing downtime during upgrades or replacements.
• Panel compatibility and retrofit readiness—engineered to work with Siemens Q-line systems, with the benefit of preserving a consistent part number for easier ordering and maintenance planning.
• Trusted brand, solid support—from Siemens, with AmpState carrying stock and offering assistance to confirm fit and compatibility when you’re planning a retrofit or replacement.

Who should consider the Q120DF

electricians and contractors upgrading existing installations to meet current safety standards, homeowners updating older panels, and facility managers overseeing retrofit projects will find the Q120DF particularly valuable. If you require reliable arc-fault and ground-fault protection in a single device without sacrificing space or complexity, this breaker is built for you.

Practical use cases

• Retrofits in homes where code requires both AFCI and GFCI protection on the same circuit, such as living areas, kitchens, or outlets near water exposure—without adding multiple devices.
• Replacing worn or obsolete breakers in Siemens panelboards where preserving the exact part number simplifies inventory and service records.
• New installations that demand compact, dual-function protection for a single 20A circuit, enabling streamlined panel layouts and fewer components.

Why this matters

AFCI protection helps prevent fires caused by arc faults, while GFCI protection guards against shock in wet or damp locations. By pairing these protections in one plug-on unit, the Q120DF minimizes nuisance trips while maximizing safety. The 1P 120V configuration is common across residential circuits, and the plug-on design lowers installation effort—saving time on retrofit projects and reducing downtime for critical circuits.

Specifications at a glance

• Amperage: 20 A
• Poles: 1
• Voltage: 120V
• Function: AFCI, GFCI, Dual-Function
• Installation: Plug-On
• Manufacturer: Siemens
• Part Number: Q120DF

Availability and support

AmpState offers the Siemens Q120DF, with guidance available to help you confirm fit and compatibility for your specific panel or load center. If you’re matching a part number for retrofits or planning a maintenance schedule, reach out and we’ll help ensure a precise, reliable upgrade.