Quick answer: Siemens Q120DFN is a 20A single-pole dual-function AFCI/GFCI plug-on-neutral breaker. Siemens QF120AN is a 20A single-pole GFCI-only plug-on-neutral breaker. They share an amp rating and neutral-connection style, but they do not provide the same protection.
Q120DFN vs QF120AN at a glance
| Feature | Q120DFN | QF120AN |
|---|---|---|
| Protection | Combination AFCI plus Class A GFCI | Class A GFCI |
| Amperage and poles | 20A, single-pole | 20A, single-pole |
| Neutral connection | Plug-on neutral | Plug-on neutral |
| AFCI protection | Yes | No |
| GFCI protection | Yes | Yes |
These specifications follow Siemens' product catalog. The panel label and its instructions still decide whether a particular breaker is approved for a particular installation.
What is the Siemens Q120DFN?
The Q120DFN product page shows a 20A, one-pole breaker that combines arc-fault and ground-fault protection. It is the dual-function choice among these two models when both functions are required and the breaker is approved for your panel. The model does not become compatible with every Siemens panel merely because it says Siemens on the front.
What is the Siemens QF120AN?
The QF120AN product page shows a 20A, one-pole GFCI breaker with a plug-on-neutral connection. It provides ground-fault protection, but it is not an AFCI breaker. Several Siemens 20 amp GFCI breaker models exist, so confirm the entire part number and connection design.
Compare the actual breakers
Which one should you order?
- Start with the required function. If the circuit requires both AFCI and GFCI, a GFCI-only QF120AN is not a direct functional substitute for Q120DFN.
- Read the panel label. Confirm the approved breaker types and plug-on-neutral design for your exact load center. Open only the hinged door; do not remove the protective cover.
- Match the complete specifications. Check the existing model, 20A rating, pole count, voltage, interrupting rating, and terminal and neutral requirements. A qualified electrician can verify the circuit and code requirements.
Do not choose a different breaker merely because it physically fits. Turning off the main breaker does not necessarily de-energize incoming terminals; installation and work inside the panel should be handled by a qualified electrician.
Frequently asked questions
Does QF120AN provide AFCI protection?
No. QF120AN is a GFCI model. If AFCI is required, verify a suitable AFCI or dual-function breaker for your panel.
Does Q120DFN provide GFCI protection?
Yes. Siemens lists it as a dual-function AFCI/GFCI breaker.
Are Q120DFN and QF120AN interchangeable?
No as a blanket rule. They provide different protection functions. The correct choice depends on the circuit requirements and the panel's approved breaker types.
Can either model go into any Siemens panel?
No. Both are plug-on-neutral designs, so check your load center's label and Siemens compatibility information for the exact model.
What if my existing breaker has another model number?
Match the full part number and panel label. Do not infer compatibility from the brand name, a similar-looking breaker, or the 20A handle marking alone.
For more options, browse our GFCI circuit breakers and dual-function breakers.