How to find the right Breakers, Load Centers & Fuses AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Breakers, Load Centers & Fuses
- Panel compatibility
- Use only breakers listed on the panel's label: the same brand and family, or UL Classified replacements explicitly approved for that panel. Breaker jaws and bus stabs differ between families. A breaker that fits but isn't listed can arc and overheat, and it voids the listing.
- Amperage matched to wire gauge
- For copper branch circuits, 14 AWG gets a maximum of 15 A, 12 AWG a maximum of 20 A, and 10 AWG a maximum of 30 A. Never upsize a breaker or fuse to stop nuisance trips. The breaker or fuse protects the wire. Oversizing it lets the wire overheat before it trips.
- Interrupting rating (AIC/kA)
- The breaker or fuse interrupting rating must be at least the available fault current at the panel. Many residential breakers are rated 10 kA, and higher-rated versions exist where the utility's fault current requires them. An under-rated device can fail violently during a short circuit.
- AFCI/GFCI/dual-function requirement
- Follow your local code's adopted NEC edition. Most living-area circuits now need AFCI protection, and wet or kitchen locations need GFCI. Dual-function breakers cover both. Replacing a protected breaker with a standard one removes required protection and can fail inspection.
- Pole count and tandem slots
- Use 2-pole breakers for 240 V loads. Install tandem or twin breakers only in panel positions the label permits. Tandems in non-rated slots overload the bus and violate the listing.
- Fuse type
- Replace a fuse with the same type and amperage. Type S fuses with matching adapters prevent overfusing in Edison-base fuse boxes. Edison-base fuses of any amperage screw into any socket, which makes overfusing easy.
Brands that matter
- Square D (Schneider Electric): QO and Homeline are separate families and are not interchangeable.
- Eaton: BR (1-inch) and CH (3/4-inch) families are not interchangeable. Eaton CL classified breakers are made for some other-brand panels.
- Siemens: QP and QT residential breakers. Also makes Murray-branded breakers.
- GE: THQL and THQP residential breakers for GE load centers.
- Leviton: Load centers and breakers, including smart-connected versions.
- Bussmann (Eaton): Common source for cartridge and plug fuses, including Type S.
What to avoid
- Breakers from unknown third-party sellers or used breakers: counterfeit breakers circulate and may not trip.
- Breakers that fit the bus but aren't listed for your panel.
- Upsizing a breaker or fuse because it keeps tripping.
- Using tandem breakers in slots the panel label doesn't allow.
- Buying replacement breakers to keep a Federal Pacific Stab-Lok or Zinsco panel in service; have an electrician evaluate replacing the panel instead.
Questions
Can I use a different brand of breaker in my panel?
Only if it is UL Classified for that specific panel and the panel's listing allows it. Otherwise, match the brand and family printed on the panel label.
Why does my breaker keep tripping?
The cause is an overloaded circuit, a short, or a ground or arc fault, not a weak breaker. Find the cause rather than installing a larger breaker.