Siemens B120AFC AFCI Miniature Circuit Breaker
- 20A
- 1 Pole
- Bolt-On
Quantity
Siemens B120AFC - 20A AFCI Miniature Circuit Breaker
New
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Description
Part of the BL series, the Siemens B120AFC delivers 20A of combination arc-fault protection for residential, commercial, and industrial electrical systems. It actively detects both series and parallel arcing conditions to mitigate fire risks. This 1-pole bolt-on breaker installs securely into Siemens P1 through P5 panelboards. Rated for 10kAIC at 120VAC, it serves as a direct, upgraded replacement for the legacy B120AF branch/feeder model and carries HACR and SWD ratings.Specifications
| Brand | Siemens |
|---|---|
| Series | BL |
| Amperage | 20A |
| Poles | 1 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120VAC |
| Frame Type | B |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3, P4, P5 Panelboards |
| Wire Gauge | 14-10 AWG (Cu), 12-10 AWG (Al) |
| Max Wire | 10 AWG |
| Min Wire | 14 AWG (Cu), 12 AWG (Al) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Special Classification | AFCI |
|---|---|
| Available Options | Padlock Attachment |
| Accessories | None included |
| Standards | CSA C22.2 No. 5, UL 489, UL 1699, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Combination Arc Fault Protection, HACR Rated, SWD Rated |
Product FAQs
8 answersWhich panelboards are compatible with the Siemens B120AFC?
This bolt-on breaker is designed for use in Siemens P1, P2, P3, P4, and P5 panelboards. It will not fit in standard residential plug-on load centers.
What is the difference between the Siemens B120AFC and the Q120AFC?
The B120AFC is a bolt-on breaker from the BL series intended for commercial panelboards. The Q120AFC is the plug-on equivalent from the Q series, designed for residential load centers.
How is the neutral connection handled on the B120AFC?
This breaker features a pigtail neutral. The coiled white pigtail wire must be connected directly to the panelboard's neutral bus bar to ensure proper arc fault detection.
What does Combination Arc Fault (CAFCI) protection mean for this breaker?
Combination AFCI breakers protect against both parallel arcs (between hot and neutral or ground) and series arcs (along a single broken or damaged conductor), significantly reducing the risk of electrical fires.
Can I install the B120AFC in an Eaton or Square D panelboard?
No. Siemens BL series bolt-on breakers are specifically listed for Siemens panelboards. Mixing breaker brands violates manufacturer listings and compromises system safety.
Does the B120AFC provide ground fault (GFCI) protection?
No. The B120AFC is strictly a Combination Arc Fault Circuit Interrupter (CAFCI). If a circuit requires both arc fault and ground fault protection, a Dual Function (DF) breaker is required.
How do I reset the B120AFC after an arc fault trip?
To reset the breaker, move the handle completely to the OFF position until it clicks, then push it back to the ON position. If it trips immediately, the fault or overload is still present in the circuit.
Does the B120AFC include a test button?
Yes, it includes a test button to verify the arc fault circuitry is functioning correctly. Siemens recommends testing the AFCI breaker monthly to ensure ongoing protection.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 35 reviews.
- TSTom S.Verified BuyerReviewingSiemens B3100 3 Pole Circuit BreakerI recommend this productRated 5 out of 5 stars8/3/26Superbreakers is our go to!
Great prices, great service and quick delivery.
- MGMaggie G.Verified BuyerReviewingSiemens B250 - 50A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/24/26Great Service
Came in great condition and in an incredibly timely manner. Will continue superbreakers for all of my orders in the future!
- DBDonnie B.Verified BuyerReviewingSiemens B115 - 15A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/11/26New Breaker
Awesome breaker & Superbreakers is a awesome company!
- BLBrian L.Verified BuyerReviewingSiemens B120 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/4/26Brian
Works great
- JFJoseph F.Verified BuyerReviewingSiemens B120 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/23/26Great value
It was a great value