Your electrical panel is one of the most important systems in your home — and most homeowners have never looked inside it. Here's a plain-language breakdown of what everything means.
The Main Breaker
At the top of your panel (usually the largest breaker), you'll find the main breaker. This controls power to every circuit in your home. The number on it — typically 100, 150, or 200 — is your home's service amperage. Flipping it off cuts power to everything except what comes in from the utility meter.
Individual Circuit Breakers
Below the main breaker are rows of individual circuit breakers. Each one controls a specific circuit (set of outlets, a room, or an appliance). The number on each breaker is its amperage:
The Circuit Directory
There should be a list on the inside of your panel door mapping each breaker number to the circuit it controls — "Kitchen countertops," "Master bedroom," "Washer," etc. If yours is blank, illegible, or wrong, that's a problem worth fixing. You can map your own with a helper: turn off breakers one at a time and identify what loses power. Or call us — mapping a panel is part of most service calls.
When a Breaker Trips
A tripped breaker ends up in the middle position — not fully on, not fully off. To reset it: push it firmly to the OFF position first, then back to ON. If it trips again:
- If it trips slowly: you're overloading that circuit. Reduce the load or add a circuit.
- If it trips instantly when reset: there's a short circuit or ground fault somewhere on that circuit. Stop using it and call an electrician.
- If it won't stay in either position: the breaker itself may have failed and needs replacement.
AFCI and GFCI Breakers
Some breakers have a TEST button on them — these are AFCI (arc fault) or GFCI (ground fault) breakers. They provide additional protection beyond standard overcurrent protection. If one trips, there's either a wiring fault or a ground fault somewhere on the circuit. Press the TEST button, then RESET. If it won't reset, call an electrician.
Warning Signs to Watch For
Any of these warrants a call to a licensed electrician immediately.
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Call (585) 371-8893Frequently Asked Questions
What does the number on a circuit breaker mean?
The number on a breaker (typically 15, 20, 30, 50) is its amperage rating — the maximum current that circuit is designed to carry before the breaker trips. Most outlets are 15 or 20 amp. Kitchen appliances often have dedicated 20-amp circuits. HVAC and EV chargers typically need 30–50 amp circuits.
What does it mean when a breaker is in the middle position?
A breaker in the middle position has tripped — it's neither fully ON nor fully OFF. To reset it, push it firmly to the OFF position first, then back to ON. If it trips again immediately, there's an underlying problem that needs a licensed electrician.
What does 100 amp or 200 amp service mean?
This is your home's total electrical capacity — the maximum current that can be drawn from the utility at one time. 100-amp service was standard in homes built before the 1980s. 200-amp service is today's standard and handles modern loads including EV chargers and heat pumps.