· by Michael Blair, Nashville's Electrician
A breaker that trips has done exactly what it exists to do. Replacing it with a larger one removes the protection without removing the problem, which is how house fires start. The useful question is which of four conditions it is reporting.
Overload: the ordinary one
Too much current on one circuit. Typically a space heater, a hair dryer or a window unit added to a circuit already carrying a load, and it trips after a few minutes rather than instantly.
The fix is redistribution or a new circuit. Older Nashville houses commonly have very few circuits serving large areas, so this is frequently a wiring-age problem rather than a user error.
Short circuit: the immediate one
Hot touching neutral or ground. It trips instantly and hard, often with a bang, sometimes with a scorch mark or a smell. A damaged cord or a failed appliance is the usual source.
If a breaker trips the instant it is reset with nothing plugged in, stop resetting it. Repeated resetting into a short is genuinely dangerous.
Ground fault and arc fault
A GFCI trips on a small current leaking to ground, which is the shock-protection function required near water. A tripping GFCI in a bathroom or outside after rain is usually moisture, and it is doing its job.
AFCI breakers detect the signature of arcing, which is what ignites fires in old wiring. AFCI nuisance tripping is common with certain motors, but a repeat trip on a bedroom circuit in an older house deserves an electrician rather than a workaround.
- Trips after minutes under load: overload
- Trips instantly and hard: short circuit
- Trips near water or outdoors after rain: ground fault
- Trips with no obvious load, older wiring: possible arc fault
When it is the breaker itself
Breakers wear. One that has tripped many times can weaken and begin tripping below its rating, and a panel in a damp garage or crawl space can corrode at the bus connection.
Certain older panel brands have documented failure-to-trip histories and are worth having assessed on sight. If your panel is original to a house from the sixties or seventies, that assessment is worth doing regardless of symptoms.