A breaker trips when a circuit is overloaded, has a short circuit or ground fault, or the breaker is faulty. Call an electrician if it keeps happening.
Main causes
- Overloaded circuit: too many devices.
- Short circuit: hot wire contacts neutral or ground.
- Ground fault: current escaping to ground.
- Faulty or aging breaker.
- Loose connections or damaged wires.
- Arc fault.
What to try
- Unplug devices on the circuit and reset.
- Plug items in one at a time to find the faulty one.
Safety
If you smell burning, see scorch marks, or the breaker feels hot, turn off the main and call an electrician.
Don’t
Replace a breaker with a larger one, which creates a fire hazard.
Statistics
The NFPA says electrical failures cause around 46,000 home fires a year.
Cost
An electrician typically charges $100 to $250 per hour.
How a breaker works
A circuit breaker is a safety switch that cuts power when current exceeds a safe level. A thermal part responds to a steady overload, and a magnetic part responds to a sudden spike from a short circuit. A standard household circuit is 15 or 20 amps at 120 volts, giving 1,800 or 2,400 watts of capacity. For safety, a continuous load should not exceed 80% of the breaker rating.
Main causes
- Overloaded circuit: too many devices, like a microwave, toaster and space heater at the same time.
- Short circuit: hot and neutral wires touch, causing a surge of current, usually due to damaged wire or a faulty device.
- Ground fault: current leaks to ground, often in wet locations and the reason for GFCI protection.
- Arc fault: damaged wires arcing and heating, which AFCI breakers detect.
- A weak or old breaker. Breakers wear out and can trip at lower loads after 20 to 30 years.
- Loose connections that heat up.
- Appliance problems, such as a failing refrigerator compressor or old dryer.
What to try
- Unplug devices on the circuit and reset the breaker. Reset fully off and then on.
- Plug items back one at a time to find the culprit.
- Spread high-wattage devices across different circuits.
- Test GFCI outlets by pressing test and reset.
- Inspect cords and outlets for damage or burn marks.
Safety
Do not replace a breaker with a higher amperage one, which can overheat the wires and cause a fire. Do not open the panel unless you are qualified. Turn off power at the main before any work.
Do not
- Do not hold the breaker on or tape it.
- Do not ignore burning smells, sparks, or hot outlets.
- Do not use extension cords as permanent wiring.
Statistics
The NFPA reports that home electrical problems cause about 32,000 to 35,000 fires a year in the US, with hundreds of deaths and over $1 billion in property damage.
Cost
A licensed electrician charges $50 to $130 an hour. Replacing a breaker costs $100 to $250. Adding a dedicated circuit costs $300 to $1,000. Panel replacement costs $1,500 to $4,000 or more.
When to call an electrician
Call if the breaker trips repeatedly, you smell burning, there is scorching, the panel is hot, lights flicker, or the panel is a known problem brand such as Federal Pacific or Zinsco.
Types of faults
Breakers protect against three main faults: overload, short circuit and ground fault. Overload happens when too many devices draw more than the circuit rating. Short circuits produce a sudden surge when hot and neutral wires touch. Ground faults happen when current leaks to ground, such as through water. Arc faults, from damaged wiring, cause high temperatures and are a leading cause of electrical fires. Federal data show electrical failures start about 34,000 home fires per year in the US. Do not tape a breaker or replace it with a higher amperage, since the wires may overheat. Faulty breakers can be replaced, typically costing 100 to 250 USD by an electrician.
Based on data from the National Fire Protection Association and the Electrical Safety Foundation International
