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 receptacles serving countertop surfaces (all of them, no distance qualifier)
- 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 | Known-defective line; recommend panel replacement |
| Zinsco | DO NOT INTERCHANGE | Known-defective line; recommend panel replacement |
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
Federal Pacific Stab-Lok panels were UL-listed and installed from the 1950s into the 1980s, and independent bench testing since has found Stab-Lok breakers failing to trip on overload at a rate no other brand comes close to. Zinsco panels have their own version of the same problem, with breakers that weld to a corroded bus and then cannot open. Get the language right with the customer: neither line was ever recalled by CPSC. The CPSC investigation into Stab-Lok closed without a recall order, and calling it recalled hands the homeowner an easy way to dismiss you when they look it up. Say it is a known-defective product line that no longer has a compliant replacement path, recommend panel replacement explicitly, and document on the customer file that you flagged it. That documentation is your protection, not theirs.
Notes
- Breaker handle ties: NEC 210.4(B) is the rule that requires a multi-wire branch circuit (two breakers sharing one neutral) to have a means that disconnects all ungrounded conductors at once; NEC 240.15(B) is what permits individual single-pole breakers with an identified handle tie to serve as that means. 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), 210.4(B) (multi-wire branch circuit disconnecting means)
- CPSC documentation on FPE Stab-Lok + Zinsco panel failures
- Manufacturer panel + breaker listing sheets
- Manuall internal: Annual Whole-Home Electrical Inspection