A circuit breaker tripping results from short circuits, overloaded circuits, and ground faults. In each case, an unintended excessive flow of current triggers the trip. You must reset the circuit breaker by flipping it back on to restore power.
Circuit breakers trip because they cannot handle the amount of current running through them. Tripping the circuit breaker interrupts the flow of electricity and protects your devices or appliances from damage.
Without electrical circuit breakers, the possibility of electrical fires would be much higher.
This guide looks at what causes circuit breakers to trip, what you can do, and how to identify a bad breaker.
What Would Cause a Circuit Breaker to Trip
There are three leading causes of circuit breaker trips:
- circuit overload
- electrical faults (i.e., ground faults and arc faults)
- short circuits
Below are factors that can cause circuit breaker trips.
A circuit overload happens when the flow of electric current running through the circuit exceeds the amperage of the devices it serves.
For example, if your microwave is a 12.5 amp appliance, you can run it on a 15 amp circuit. That means your microwave is safe as long as the amperage running through the circuit is 15 amps.
However, if the circuit receives an excessive electrical load over 15 amps, it will automatically trip to protect your device from damage. If the circuit doesn’t trip, the excess current will fry the circuit in your microwave.
Also, if you operate too many appliances and devices on one circuit, its internal mechanism heats up, causing the breaker to trip.
Circuit overload is the most common reason for breakers tripping.
A ground fault occurs when the active wire comes into contact with a ground wire made of bare copper. Sometimes, this fault may happen when the hot wire touches the metal box connected to the ground wire.
Excessive current flows once the active wire touches the ground wire, flowing into the earth. If you step on the affected area, ground faults can cause shock and even electrocution. The uncontrolled flow of electricity will cause the circuit breaker to trip.
A short circuit occurs when an active wire touches a neutral wire, and the electrical current takes an unintended path of least resistance.
The common cause of short circuits is frayed wires coming into contact when the wires touch. The electrical current flow increases significantly, causing the circuit breaker to trip to stop the electricity from damaging appliances.
It is a short circuit because the current bypasses the proper circuit wiring channels and flows through a shorter, unplanned pathway.
Short circuits occur
- When insulation melts and wires are exposed
- Within appliances with damaged internal wiring
- Due to damaged and frayed extension or appliance cords
How do You Fix a Breaker that Keeps Tripping?
A dedicated circuit breaker tripping indicates too much current flowing through the wiring or connection to the outlet.
Here is a step-by-step guide to follow when you notice the first trip:
- Begin by turning off all the appliances and unplug electrical devices from the outlet. Also, switch off light fixtures and unplug those that you can. This prevents any appliances from damaged when the breaker is reset and a sudden surge of power comes through.
- Open the circuit panel or box and locate the on and off buttons of the circuit breaker. You may notice an orange or red color on the breaker when it is off.
- Flip the switch from off to on to reset the circuit breaker. Once the breaker is reset, you can switch and test the appliances to see if the electrical power is flowing.
- Keep safe as you reset the breaker by working from the side of the electrical box instead of the front. That way, you will avoid any sparks (should there be any) when you switch the breaker back on.
- Some people prefer to switch the main electrical switch when working on the circuit breaker for added safety.
Types of Circuit Breakers
Standard Circuit Breaker
Standard circuit breakers monitor the modulation of the electric current coming into your devices and appliances.
This circuit breaker stops the current from flowing when it detects the excessive flow of electricity.
Standard circuit breakers come in two forms:
- Single-pole circuit breakers
- Double pole circuit breakers
Single-Pole Circuit Breakers
Single-pole circuit breakers are the most common breakers in homes and buildings. They monitor the electric current’s flow in one wire and trip if that wire experiences a very high influx of electricity.
These breakers deliver only 120 volts and work well for 15 to 30 amp circuits. Single-pole circuit breakers come with one switch in the back.
Double-Pole Circuit Breakers
The double-pole circuit breakers monitor the current in two wires simultaneously. You will notice two switches on the back of these breakers.
The double-pole circuit breakers will trip even if only one of the wires receives too much current. They can accommodate between 15 to 200 amps while delivering 240 volts.
Single-pole breakers are a good fit for lighting fixtures and other standard home outlets. On the other hand, double-pole breakers work for larger appliances like dryers and washing machines.
Ground Fault Circuit Interrupter (GFCI)
The GFCI circuit breaker interrupts the line due to ground faults. They trip when the current starts to follow an uncharted path into the ground. These ground fault surges occur when a foreign conductor, like water, comes in contact with a receptacle.
At the same time, they offer protection against circuit overloads and short circuits.
GFCI circuit breakers come built into specialized outlets required for wet areas in the home, including:
- Outdoor areas like the balcony, patio, porches, and decks
- Laundry rooms
- Swimming pools
- Six feet from a sink
- Six feet from the bathroom
These breakers help prevent shock or electrocution should the electrical outlet contact water.
Arc Fault Circuit Interrupter (AFCI)
The AFCI circuit breaker detects normal and abnormal arc faults, so it will trip when it detects a dangerous arc fault that can cause a fire.
The AFCI circuit breaker doesn’t work to protect devices and appliances plugged into an outlet. It works to prevent electrical fires due to faulty connections and wiring. The internal sensing mechanism in the circuit breaker senses the conditions of an electric arc, and the circuit trips to avoid an electric fire.
AFCI protection can also be built into an outlet. The National Electrical Code (NEC) requires these types of breakers to feature in:
- Common rooms
- Laundry areas
Combination All Fault Circuit Interrupter (CAFCI)
The CAFCI breaker senses and reacts to any electrical fault, including ground and arc faults.
CAFCI is a relatively new technology that meets new NEC requirements for circuits requiring arc and ground fault protection.
Do Circuit Breakers Get Weak?
A circuit breaker can wear out and become weak. If a breaker trips frequently, the thermal or magnetic element can lose calibration, causing it to trip at lower amp loads than intended. A breaker constantly under thermal stress caused by overloading the circuit will eventually trip more frequently.
Let’s not forget breakers are not impervious to damage. As the internal mechanical parts wear out, they become very sensitive and may not hold under normal load amperage and temperatures.
Electricians refer to this as a bad breaker.
Will a Bad Breaker Keep Tripping
By definition, bad breaker malfunctions, so it will keep tripping until it is either replaced or rectified.
A licensed electrician performs this simple test to see if a breaker will keep tripping and determine if it can be repaired or replaced in the following steps.
- The electrician will switch off all the fixtures and appliances in the house. Also, unplug everything.
- Find the malfunctioning circuit breaker. The electrician will go to the electrical box and locate the breaker lighting orange or red or the one with the switch off.
- They will ascertain that it is the correct circuit breaker. After that, the electrician puts the breaker off.
- With the switch on, the breaker is back on as well. The electrician will plug the appliances into the outlet with the problem circuit breaker. Now, they will turn the devices and appliances on.
If the breaker trips, the electrician will investigate the circuit’s current amount. The breaker is bad if the current is according to the appliance’s rating.
How You know if a Circuit Breaker is Bad
Breakers do wear out after a while. It has a problem if the breaker doesn’t stay on after resetting it.
Since the circuit breaker controls the electric flow in the house, it is essential to monitor it and catch signs that it has gone bad early.
Here are key signs that denote a bad circuit breaker:
It Frequently Trips
Frequent tripping could be because of a bad breaker. After tripping and resetting, your circuit breaker should stay on unless it detects high current flow.
To ensure that the issue is not the electricity but the circuit breaker, call an electrician to examine your electricity’s flow and determine whether it is the cause of the constant tripping.
If it is not, then the circuit breaker is the problem.
The Breaker Overheats
Electrical systems will heat up when active. Typically a breaker can heat to about 60°C (140°F) before problems arise.
Terminations for standard rated breakers: UL 489 Paragraph 18.104.22.168.2 says the temperature rise on a wiring terminal at a point to which the insulation of a wire is brought up as in actual service shall not exceed 50°C (122°F).
Terminations for 100% rated breakers: UL489 Paragraph 22.214.171.124.3 says the temperature rise on the termination shall not exceed 60°C (140°F).
Handles, knobs, and other user surfaces: UL489 Paragraph 126.96.36.199.6 says the maximum temperature on handles, knobs, and other surfaces subject to user contact during normal operation shall not exceed 60°C (140°F) on metallic and 85°C (185°F) on nonmetallic surfaces.Source: https://www.clipsal.com/faq/fa173839
Call an electrician immediately if the breaker becomes too hot.
There are Scorch Marks
Scorch marks around receptacles, appliances, and the electrical box should tell you your circuit breaker has gone bad.
The burn marks indicate that wiring insulation has melted off and the circuit wires are now sparking and emanating heat or fire. That means that the circuit breaker did not interrupt the excess current and reached the wires and burned them.
You may see melted wire sheathing on the wire where it connects to the breaker.
Professional electricians can use a thermal imaging infrared camera to locate the heat source. The infrared camera allows them to pinpoint the problem area through the walls and other construction material.
A Burning Smell
Sometimes you may smell the insulation burning, but no scorch marks are present to denote which outlet is the problem.
With the help of the infrared camera, an electrician can help locate electrical issues.
If you encounter a burning odor, shut off the main power and call for emergency service from an electrician.
The electrical wires burn because power surges through the circuit, melting the wire insulation.
What is Nuisance Tripping
Nuisance tripping is when a breaker trips without a fault to warrant the interruption to the electric current flow.
Nuisance tripping occurs due to several reasons:
Stringent Protection on Circuits
Sometimes the circuit is protected by stringent conditions that detect any variance as a fault and cause a trip.
Such stringent conditions can be tuned to accommodate the home’s or building’s electric needs.
A Highly Sensitive Circuit Breaker
In some cases, the circuit breaker has been set to susceptible settings so that they can detect even the slightest fault, even a minor average variance.
For example, the manufacturer can set an AFCI circuit breaker to sensitive standards to detect another circuit’s arc. This common issue may occur in a daisy chain where the circuit breakers connect in a linear series. There may be a faulty electrical outlet you are unaware of on the circuit. It is common for multiple rooms to share a breaker in older houses.
The Breaker Encounters Power Under Different Conditions
The variation in the current is normal, but the breaker responds to it by tripping because the flow is outside the breaker’s regular operation.
Your circuit breaker is tripping because the voltage it is encountering is not within the standard operation. You will need to adjust the circuit breaker or the voltage to eliminate nuisance tripping.
The Breaker Trips with Nothing Plugged in
A breaker tripping with nothing plugged in occurs when a hot, neutral wire is touching somewhere in the circuit. The common causes include frayed or damaged electrical wires, loose connections, faulty electrical receptacles, light switches, or dimmers.
Electrical wire damage happens when:
- wiring is chewed by animals such as rats, squirrels, raccoons, etc
- wire sheathing and insulation ages and become frayed
- wires rub against sharp edges such as punch-outs with missing grommets or wire clamps
Loose connections often occur when electrical wire nuts come loose or electrical tape wears out causing wires to touch.
Defective wiring can be anywhere along the circuit, so it’s best to contact a licensed electrician to troubleshoot why the breaker is tripping.
Replacing a Bad Circuit Breaker
- Check the electrical panel to see the compatible approved circuit breaker brands. Also, make a note of the brand of the electric panel. This is to help you determine if there are upgrades they could recommend for the hardware.
- Order online or go to the hardware store and purchase the breaker of the same voltage as the one you are replacing.
- Go and open the electrical box and switch off the bad breaker. Loosen the terminals and remove the wires using a pair of needle-nosed pliers. Ensure the pliers have rubber insulated handles to avoid shock or electrocution since you will use the pliers to grab the live wires from the terminal. That is a safety measure.
- Remove the bad breaker. Replace it with the new breaker and slip its clips into place. Remember to switch off the replacement breaker.
- Next, using the pliers, hold the wiring and tighten the screws on the terminal. It is crucial to ensure that the wires and screws in the terminals are in the right place.
- Turn the breaker on and replace the electrical panel cover.
Can a Breaker Fail Without Tipping
The main reason Federal Pacific was investigated by the Consumer Products Safety Commission (CPSC) was widespread structure fires involving breakers failing to trip when an electrical overload was present. They found that the circuit breaker contacts would fuse to the bus bar.
Modern breakers will trip when a failure occurs as an added layer of safety. Most older breakers did not have these safeguards.
With AFCI breakers, if the Internal sensing mechanism fails, the breaker reverts to a standard breaker. The AFCI sensor mechanism will no longer work, but the breaker would still trip from overcurrent protection. Therefore, you should test the AFCI breaker regularly.
Listen to your circuit breaker. It’s alerting you of a problem when it trips. That communication could be a problem with the breaker itself, the circuit, or the amount of electric current coming into your home.