Electrical panels are the backbone of every building's power distribution. Here is a guide to the key components and common replacement parts.
Circuit Breakers
### Standard Breakers Single-pole (120V) and double-pole (240V) breakers are the most commonly replaced panel components. They protect circuits from overcurrent. When a breaker trips repeatedly or will not reset, it needs replacement.
### GFCI Breakers Ground fault circuit interrupter breakers protect against ground faults. Required by code in bathrooms, kitchens, garages, and outdoor circuits. They have a test button and are more expensive than standard breakers. Cost: $30-60 vs $5-15 for standard.
### AFCI Breakers Arc fault circuit interrupter breakers detect dangerous arcing conditions. Required by current code in bedrooms and living areas in most jurisdictions. Cost: $30-50.
Brand Compatibility
Breakers are NOT interchangeable between brands. A Square D breaker will not fit a Siemens panel and vice versa. Some brands have classified breakers that are UL-listed for use in other panels, but always verify compatibility.
### Common Panel Brands - **Square D (Schneider)** — QO (full size) and Homeline (value) series - **Siemens** — QP series - **Eaton** — BR and CH series - **GE** — THQL series - **Cutler-Hammer (Eaton)** — CH and BR series
Bus Bars and Neutral Bars
If you need additional spaces for AFCI or GFCI circuits, auxiliary ground/neutral bars can be added to most panels. Cost: $5-15.
Finding Panel Parts
Search your breaker type (e.g., "Square D QO 20 amp") on PartHawk. We search Home Depot, Grainger, Amazon, and specialty electrical suppliers to find the best price instantly.