Circuit Breaker Keeps Tripping: Overload, Short, or Ground Fault

A breaker that trips is a working breaker. Resetting it repeatedly without understanding why is how the protection stops protecting you.

There are three reasons it trips, and they are distinguishable.

1. Overload — too much current on the circuit

Signature: trips after a few minutes of use, especially when you add an appliance. Reset works, and it runs again until the same load returns.

A 15 A circuit at 120 V supports 1,800 W absolutely, and 1,440 W as a continuous working limit (80%). It is easy to exceed:

Appliance	Typical draw
Space heater	1,500 W
Hair dryer	1,200–1,875 W
Microwave	1,000–1,500 W
Kettle	1,500 W
Vacuum	700–1,400 W

Two of those on one circuit is a trip. Fix: move loads to another circuit, or have a dedicated circuit installed for the big one. A space heater deserves its own circuit.

2. Short circuit — hot touching neutral

Signature: trips instantly, every time, often with a bang, a flash, or a burning smell. It will not stay reset with the faulty thing connected.

Find it by unplugging everything on the circuit and resetting. If it holds, plug things back one at a time. If it trips with nothing connected, the fault is in the fixed wiring or a device box, and that is electrician territory.

Common causes: a damaged cord, a failing appliance, a screw driven into a cable, rodent damage, or a loose wire in an outlet or switch box.

Do not keep resetting into a short. The fault current is high enough to ignite whatever it is arcing against.

3. Ground fault — current escaping to earth

Signature: the tripping device is a GFCI/RCD outlet or breaker, and it trips in bathrooms, kitchens, garages, or outdoors — often in wet weather.

These trip at 5–6 mA, far below what a normal breaker sees, because that is the threshold that protects a person rather than the wiring.

Causes: moisture in an outdoor outlet or box, a deteriorated appliance cord, a failing motor’s windings, or simply a GFCI that has reached end of life (they wear out — test them monthly with the test button).

An outdoor circuit that trips only when it rains usually needs a proper weather cover and a gasket, not a new breaker.

Also: arc faults

AFCI breakers, now required in bedrooms and living areas in much of the US, detect the signature of arcing rather than overcurrent. They nuisance-trip on some motor loads and older vacuum cleaners, but they also catch genuine loose connections that would otherwise start a fire. An AFCI tripping repeatedly on one circuit deserves investigation, not replacement with a standard breaker.

When the breaker itself is the problem

Breakers are mechanical and they fatigue. A breaker that trips well below its rating, feels warm, or will not reset firmly may have failed internally. That is plausible — but it is the last conclusion, not the first, and swapping a breaker to make a symptom disappear is exactly how a real fault gets hidden.

Stop and call an electrician if

• The panel or a breaker is warm, discoloured, or smells of burning.
• You hear buzzing or crackling from the panel.
• Multiple circuits trip together, or lights dim across the house.
• A breaker trips with everything unplugged.
• You have aluminium branch wiring, a known-defective panel brand, or no ground.

Panel work is the part of household electrics with no forgiving margin: the main lugs stay live with the main breaker off.

Reading your panel

Two numbers matter on each breaker, and both are printed on the handle.

Amperage — 15 A and 20 A for general circuits, 30–50 A for dryers, ranges, and EV chargers. A breaker’s rating must match the wire it protects, not the appliance: 14 AWG wire takes a 15 A breaker, 12 AWG takes 20 A. Fitting a 20 A breaker on 14 AWG wire is a fire waiting to happen, and it is a mistake people make specifically to stop nuisance trips.

Poles — a single-pole breaker occupies one slot and serves 120 V; a double-pole occupies two and serves 240 V. A 240 V appliance tripping only sometimes may have one pole failing.

Calculating what a circuit can carry

Continuous load should not exceed 80% of the breaker rating:

Breaker	Absolute	Continuous limit
15 A at 120 V	1,800 W	1,440 W
20 A at 120 V	2,400 W	1,920 W
30 A at 240 V	7,200 W	5,760 W

Add up the nameplate wattage of everything on the circuit. If the total sits near the continuous limit, the breaker will trip eventually — usually in winter, when the space heater comes out.

Finding what is on a circuit

Switch the breaker off and walk the house with a lamp or a socket tester. Note every dead outlet, switch, and light. It takes twenty minutes and it makes every future decision easier — label the panel while you are at it.

You will often find a circuit spans more rooms than you expected. Bedroom outlets sharing a circuit with a bathroom, or a garage freezer on the same circuit as an outdoor socket, explains a lot of otherwise puzzling trips.

The GFCI test habit

GFCI and RCD devices are mechanical and they fail — sometimes failing to trip, which is the dangerous direction. Press the test button monthly. The reset should pop out and power should be lost; if it does not, the device needs replacing.

One detail that confuses people: a single GFCI outlet often protects several downstream outlets on the same circuit. If a bathroom outlet is dead, the tripped GFCI may be in another room, or in the garage. Look for the reset button elsewhere before assuming a fault.

Nuisance trips vs real faults

The distinction matters, and the test is repeatability:

• A trip that happens once and never repeats with the same load is usually a transient — a motor’s inrush current, a brief surge.
• A trip that repeats with the same appliance is that appliance.
• A trip that repeats with nothing connected is the wiring.
• A trip on a schedule — every morning, every time the heating starts — points at a specific load you can identify by what else happens at that moment.

Keep a note of what was running each time. That log answers the question faster than any instrument.

What it costs to do properly

Having an electrician add a dedicated circuit is a modest job in an accessible panel with room for another breaker, and considerably more if the panel is full and needs replacing or a sub-panel added. Either is cheaper than a fire, and both are cheaper than the panel replacement you will need anyway if the existing one is one of the brands known for failing to trip.

If your house still has a fuse box, aluminium branch wiring, or no ground on the outlets, get an inspection rather than chasing individual symptoms.