Common Residential Breaker Types
Identification
Residential circuit breakers come in multiple functional types, brand-specific physical formats, and varying amp ratings. Picking the wrong format can damage the panel; picking the wrong functional type can fail to protect against the hazard the customer needs covered. This datasheet covers the functional types, panel compatibility, and selection criteria.
Specifications
Functional types:
Standard thermal-magnetic - single-function overcurrent + short-circuit protection. The baseline breaker; appropriate for general-purpose circuits where AFCI/GFCI isn't required by code.
GFCI (Ground-Fault Circuit Interrupter) - trips on ground-fault current as low as 5 mA. Required by NEC on circuits feeding:
- Bathroom receptacles
- Kitchen counter-receptacles within 6' of a sink
- Outdoor receptacles
- Garage receptacles
- Crawlspace receptacles
- Unfinished basement receptacles
- Pool / spa equipment circuits
AFCI (Arc-Fault Circuit Interrupter) - trips on the electrical signature of an arcing fault (loose connection sparking, damaged wire arcing to ground). Required by NEC on most habitable-space branch circuits in new construction:
- Bedrooms (NEC 1999+)
- Living rooms, dens, family rooms (NEC 2008+)
- Most other habitable rooms (NEC 2014+)
Dual-function (CAFCI / DFCI) - combines AFCI + GFCI in one device. Required where both protections are needed (kitchens, laundry rooms in newer NEC adoptions).
Materials
Brand compatibility (residential):
| Brand | Format | Notes |
|---|---|---|
| Square D HOM (Homeline) | Plug-on | Most common newer residential; affordable |
| Square D QO | Plug-on (visible trip indicator) | Premium Square D; some commercial use |
| Eaton CH | Plug-on (color-coded ratings) | High-quality residential |
| Eaton BR | Plug-on (interchangeable with Westinghouse) | Common residential |
| Siemens (formerly ITE) | Plug-on | Common in mid-market homes |
| GE / ABB | Plug-on | Many older homes |
| Murray (now Siemens-compatible) | Plug-on | Legacy + new |
| Federal Pacific Stab-Lok | DO NOT INTERCHANGE | RECALLED - replace panel |
| Zinsco | DO NOT INTERCHANGE | RECALLED - replace panel |
You CANNOT mix manufacturers in a panel. A Square D HOM breaker in an Eaton panel may physically fit but doesn't connect securely to the bus; it will overheat and fail. Some "universal" breakers exist (Connecticut Electric brand) but check manufacturer + UL listing carefully.
Performance
Standard amp ratings (residential):
- 15A - general-purpose circuits, lighting + receptacles on 14 AWG
- 20A - small-appliance circuits, kitchen counter, bathroom, laundry receptacles on 12 AWG
- 30A - 240V dryer, 240V water heater on 10 AWG
- 40A - 240V range / cooktop, 240V AC condenser on 8 AWG
- 50A - 240V range, 240V EV charger on 6 AWG
- 60A - sub-panel feeder
- 100A / 125A / 200A - main breakers on residential service panels
Safety
The Federal Pacific Stab-Lok panel was UL-listed in the 1950s - 1980s but extensive failure-rate testing showed Stab-Lok breakers fail to trip under overload at rates 4x higher than other brands. The same applies to Zinsco panels. NEVER service a recalled panel without explicitly recommending replacement. Documenting that you flagged it on a customer file is professional self-protection.
Notes
- Breaker handle ties are required by NEC 240.15(B) on certain multi-wire branch circuits (shared neutral between two breakers). A handle tie or 2-pole breaker is mandatory; using single breakers without a tie violates code AND creates a shock hazard.
- Combination AFCI has caused widespread "nuisance trip" complaints in older homes with marginal wiring. The nuisance trip is the AFCI doing its job (it sees the marginal connection); the fix is improving the wiring, not bypassing the AFCI.
- GFCI breaker vs GFCI receptacle: a GFCI receptacle wired LOAD-side protects everything downstream. For a bathroom with multiple outlets, one GFCI receptacle (or GFCI breaker) at the start of the run covers all downstream outlets.
- Disposable vs reusable: when a breaker trips persistently and is suspect, replace it. Breakers wear; one-time trips are normal but a repeated tripper isn't field-rehabbable.
References
- NEC Articles 240 (Overcurrent Protection), 210.12 (AFCI), 210.8 (GFCI)
- CPSC documentation on FPE Stab-Lok + Zinsco panel failures
- Manufacturer panel + breaker listing sheets
- Manuall internal: Annual Whole-Home Electrical Inspection