A circuit breaker is an electrical safety device for protecting any electrical circuit from excessive current flow. To avoid damage or fires, the circuit breaker will “trip” or open if the total current through it surpasses its regulated limit.
A circuit breaker can trip for various reasons, such as overloading, short circuits, ground faults, or a faulty breaker. When a circuit breaker trips, it prevents electricity from flowing to the impacted circuit, which results in a power outage in that location.
In this article, I will show you how to test if a circuit breaker will trip in 4 ways! So, stay with us until the end.
| Test Type | Estimated Required Time |
| Multimeter Test | 20-30 minutes |
| Voltmeter Test | 20-30 minutes |
| Volt Stick Test | 15-20 minutes |
| Clamping Ammeter Test | 20-30 minutes |
How To Test If A Circuit Breaker Will Trip?
It is important to note that working with electricity can be dangerous, and if you need help with how to perform these steps, it’s best to seek the help of a qualified electrician.
Multimeter Test
Required Tools
- A multimeter.
- Safety gloves.
- Safety glasses.
Steps
- Ensure the circuit’s power is turned off before starting the test.
- Set your multimeter to measure resistance (ohms).
- Pull the wires out from the circuit breaker terminals.
- Touch the multimeter probes to the circuit breaker terminals.
- Check the resistance reading on the multimeter. It should read infinite or open circuit, indicating that the circuit breaker is in the open position.
- If the resistance reading is low or zero, the circuit breaker is not tripped or in the closed position.
- Connect the wires back to the circuit breaker terminals to check if the circuit breaker trips properly.
- Turn on the power to the circuit.
- Use a multimeter to calculate the current coursing through the circuit.
- Increase the current slowly until the circuit breaker trips.
- Note the current reading on the multimeter at the point where the circuit breaker tripped.
- Compare the current reading to the circuit breaker’s rated current, which should be listed on the breaker.
- If the current reading exceeds the circuit breaker’s rated current, the circuit breaker must be replaced.
Voltmeter Test
Required Tools
- A voltmeter.
- Safety gloves.
- Safety glasses.
Steps
- Turn off the power to the circuit breaker that you want to test.
- Set your voltmeter to measure AC voltage.
- Release the wires from the terminals.
- Turn on the power to the circuit.
- Touch the voltmeter probes to the circuit breaker terminals.
- Check the voltage reading on the voltmeter. It should read zero volts, indicating no voltage present because the circuit breaker is open.
- If the voltmeter reads any voltage, it indicates that the circuit breaker is not tripped or in the closed position.
- Connect the wires back to the circuit breaker terminals to check if the circuit breaker trips appropriately.
- Turn on the power to the circuit.
- Use a voltmeter to measure the voltage at the load end of the circuit.
- Increase the current slowly until the circuit breaker trips.
- Note the voltage reading on the voltmeter at the point where the circuit breaker tripped.
- Compare the voltage reading to the circuit breaker’s rated voltage, which should be listed on the breaker itself.
- If the voltage reading is higher than the circuit breaker’s rated voltage, the circuit breaker needs to be replaced.
Volt Stick Test
Required Tools
- An electrostatic wand or volt stick.
- Safety gloves.
- Safety glasses.
Steps
- Turn off the power to the circuit breaker that you want to test.
- Hold the volt stick close to the circuit breaker.
- A volt stick or electrostatic wand can show if a wire is ‘hot’ without touching it.
- Turn on the power to the circuit.
- Check the volt stick’s indicator light. It should not light up or make any noise, indicating no voltage present because the circuit breaker is open.
- If the indicator light on the volt stick lights up or makes any noise, it indicates that the circuit breaker is not tripped.
- Ensure not to hold the volt stick closer to the ground because it may pick up electrical signals from any ground wires.
- To check if the circuit breaker trips correctly, turn off the power to the circuit.
- Connect the wires back to the circuit breaker terminals.
- Turn on the power to the circuit.
- Use the volt stick to check the voltage at the load end of the circuit.
- Increase the current slowly until the circuit breaker trips.
- Check the volt stick’s indicator light at the point where the circuit breaker tripped.
- If the indicator light lights up or makes any noise, it indicates that voltage is present and the circuit breaker is opening the circuit.
- If the indicator light does not light up or make any noise, it may indicate a faulty circuit breaker and should be replaced.
Clamping Ammeter Test
Required Tools
- A clamping ammeter.
- Safety gloves.
- Safety glasses.
Steps
- Make sure the circuit breaker is turned off before testing.
- Locate the wires that are connected to the circuit breaker.
- Turn on the power to the circuit.
- Using the clamping ammeter, clamp it around one of the wires attached to the circuit breaker.
- The clamping ammeter is a great circuit breaker tester for checking shorts and overloads.
- Inspect the reading on the ammeter. It should read zero amps since the circuit is not being used.
- Turn on the circuit and monitor the reading on the ammeter.
- The reading on the ammeter should increase as current flows through the circuit.
- If the current exceeds the rated amperage of the circuit breaker, the circuit breaker should trip, and the ammeter reading will drop to zero.
- If the circuit breaker does not trip, turn off the circuit immediately and consult a professional electrician to identify the issue.
Remember always to follow appropriate safety precautions when working with electrical circuits.
Why Your Circuit Breaker Is Tripping?
Overloaded Circuit
If a circuit is drawing more current than it is designed for, the circuit breaker will trip to prevent overheating and potential fires. This may occur if you use power-hungry appliances like air conditioners or space heaters or put too many devices or appliances into one circuit.
Short Circuit
When a hot wire touches a neutral wire, a short circuit provides an electrical path with minimal resistance. This can cause the circuit breaker to trip immediately, as the sudden current surge can be dangerous and cause damage to your wiring.
Ground Fault
A ground fault happens when a hot wire touches a ground wire or a grounded surface. This can also cause a sudden current surge and trip the circuit breaker.
Aging or Faulty Breaker
Circuit breakers can wear out over time or become faulty due to corrosion, loose connections, or other issues. In these cases, the breaker may trip frequently or even fail to trip at all, which can be dangerous.
Electrical Storms or Power Surges
Lightning strikes or power surges can cause a sudden spike in voltage that can overwhelm your electrical system and trip the circuit breaker. Installing surge protectors can assist in protecting your appliances and preventing damage.
GFCI Tripping
Ground Fault Circuit Interrupters (GFCIs) are designed to protect against electric shock by tripping when there’s a ground fault or a current imbalance. If your GFCI is frequently tripping, it may be because of a faulty appliance or a problem with the wiring.
Other Issues
Other potential causes of circuit breaker tripping include faulty wiring, rodents or other pests chewing on wires, or DIY electrical work that has gone wrong. It’s always best to consult a licensed electrician if you’re experiencing frequent tripping or other electrical issues.
What To Do If Your Circuit Breaker Is Tripping?
Let’s say your circuit breaker is frequently tripping, and you have identified the issue using this article. What’s the next step?
Let’s review some safety measures and the must-to-do if your circuit breaker is tripping.
- Unplug Devices: If you suspect an overloaded circuit is a problem, try unplugging some devices to reduce the load on the circuit. Move high-powered appliances like air conditioners or space heaters to a separate circuit if possible.
- Reset the Breaker: Once you’ve identified the cause of the problem, try resetting the circuit breaker by turning it off and then back on again. This will restore power to the circuit and allow you to test whether the issue has been resolved.
- Call an Electrician: If the breaker continues to trip or if you’re unsure about the cause of the problem, it’s best to call a licensed electrician. They can diagnose the issue and provide professional repairs or upgrades to your electrical system.
- Consider Upgrades: If your circuit breaker is frequently tripping due to an overloaded circuit, you may need to upgrade your electrical system to handle the demand. This could involve installing additional circuits, upgrading your wiring, or replacing your electrical panel.
- Practice Electrical Safety: To prevent future tripping issues, make sure you’re using your electrical system safely and responsibly. Avoid overloading circuits, use surge protectors to protect your devices, and never attempt DIY electrical work unless you’re a trained professional.
- Stay Alert: Keep an eye on your electrical system and watch for any signs of trouble, such as flickering lights, strange sounds, or burning smells. Immediately prevent a potential electrical fire or other hazards if you notice anything unusual.
Preventative Maintenance For A Circuit Breaker
To prevent circuit breaker issues, it’s important to schedule regular inspections with a licensed electrician. They can check for wear or damage, test your circuits and breakers, and recommend necessary repairs or upgrades.
Keep Your Electrical System Clean
Dust and debris can accumulate on your electrical system, interfering with proper function and causing overheating. Ensure your electrical system is clean and free of dust and debris.
Don’t Overload Circuits
Overloading circuits is one of the most ordinary reasons for circuit breaker tripping. To prevent this, avoid plugging too many devices into a single circuit and use separate circuits for high-powered appliances like air conditioners or space heaters.
Use Surge Protectors
Power surges can damage your electrical devices and cause fires. Protect your devices by using surge protectors, which can absorb the excess voltage and prevent it from reaching your devices.
Final Words
In conclusion, testing a circuit breaker is essential in ensuring an electrical system’s safety and functionality. Several methods exist to test a circuit breaker, including using a voltmeter, a multimeter, or a clamping ammeter test.
However, following the manufacturer’s instructions and safety guidelines when testing a circuit breaker is crucial to avoid any accidents or damage to the electrical system.
By regularly testing your circuit breakers, you can identify any faults or malfunctions and take the necessary steps to prevent any potential hazards.
So, test your circuit breakers periodically to ensure they will trip when needed and keep your electrical system safe and secure.
FAQ
How do you test a MCB trip?
To test an MCB trip, turn off all connected appliances, turn off the MCB, create an overload or short circuit, turn the MCB back on, and verify that it trips and switches off the circuit.
At what current does MCB trip?
The current at which an MCB (Miniature Circuit Breaker) trips depends on its rating, usually indicated on the device. MCBs are available in different ratings, ranging from 1 amp to 63 amps or higher.
Each MCB is designed to trip at a specific current level, known as its “trip current” or “breaking capacity.”
For example, an MCB rated at ten amps will trip when the current in the circuit exceeds ten amps, whereas an MCB rated at 32 amps will trip when the current exceeds 32 amps.
These units can trip and shut off the power source in the event of short circuits within 2.5 milliseconds.
How do you fix a tripped breaker?
To fix a tripped breaker, first, identify which breaker has tripped. Next, turn the breaker off by pushing it to the “off” position, then back on by pushing it to the “on” position. The problem may have been a temporary overload or short circuit if it stays on.
If it trips again immediately, unplug all the devices from the circuit and try again. If it still trips, there may be a fault in the circuit, so consult a qualified electrician to diagnose and fix the problem.