I don’t know much about electricity, plugs, circuit breakers, and such, except that electricity can kill you if you don’t know what you’re doing and touch the wrong thing.
I did once dare to replace a copper lantern outside my front door – turned the switch off, shut the circuit breaker off, wore my sneakers with rubber soles, turned around three times and spit on the ground, and wrote everything down – colors of wires, where they went on the lantern being replaced – everything I could think of.
Since I’m writing this piece today, you know I didn’t get electrocuted.
Tripping a circuit breaker when you turn on or operate your table saw, though, is a different animal. Electricity and a rapidly spinning blade with sharp tips are a little bit scary. Where to look, what to check, and safety precautions to follow when doing so all come into play.
Still, we woodworkers are creative and daring, to a point, and calling for outside help isn’t our first choice. We’re tough and rugged and can fix things on our own.
But where to look? What to look for?
We know that somewhere between the motor of the table saw and the breaker is a problem, but that doesn’t narrow it down too much, especially when you don’t know much about electricity.
However, we can point you toward a few possibilities and their cures, cures that even a woodworker can handle. Circuit breaker trips are annoying, but it may not necessarily be the saw. Start with the breaker and then work back through the various cords (power and extension) as you diagnose.
Key Points:
- Start with the circuit breaker box as you begin to diagnose. It might be an old, weak breaker that should be replaced. It’s not a difficult task, and breakers are inexpensive. The circuit breaker box is the main electrical panel for your house (assuming you are home shop woodworkers). It’s safe to open the breaker box, and if it was installed well, each breaker will be labeled to identify as to room, outlet, etc.
- Next, and working back from the breaker, check the power cord and any extension cord you might be using to make sure the plug is secure and the wiring is not frayed. As a test, plug another power tool into the same outlet to see if the breaker trips. If not, move on to the next suspect.
- Then, check the switch on the saw to see if it is loose or a connecting wire is frayed.
- Finally, the motor. Clean it, check the motor shaft, motor coil, brushes, and vents. Or, if you’ve ruled everything else out and you’re left with the motor as the culprit, bring it to a professional for a diagnosis.
Electricity – What Is The Difference Between Volts and Amps?
Volts and amps are two different measures of electricity.
- Volts measure the electrical potential difference between two points in an electric field. This is the force that pushes the electrons through a circuit.
- Amperes measure the rate of current flow in a conductor or a circuit. This is the number of electrons flowing through the circuit per unit of time.
In other words, volts measure the pressure of electricity, while amps measure the flow of electricity.
The relationship between volts and amps is given by Ohm’s law, which states that the current flowing through a circuit is equal to the voltage divided by the resistance.
- Power is the rate at which electrical energy is transferred in a circuit. It is measured in watts and is calculated by multiplying the voltage by the current.
So, to answer your question, volts and amps are not directly comparable. They are two different measures of electricity that are related by Ohm’s law.
Here is a table summarizing the differences between volts and amps:
| Property | Volts | Amps |
| Unit of measurement | Volt (V) | Ampere (A) |
| What it measures | Electrical potential difference | Current flow |
| Relationship to other units | Voltage is related to current by Ohm’s law: I = V/R | Power is related to voltage and current by P = V*I |
| Common examples | The voltage of a battery | The current flowing through a light bulb |
What Is The Common Voltage and Ampere In A Circuit Breaker?
The common voltage and ampere in a circuit breaker in a residential setting are 120 volts and 15 or 20 amps. This means the circuit breaker can handle a maximum current of 15 or 20 amps.
However, there are also circuit breakers that are rated for other voltages and amperages. For example, circuit breakers for commercial or industrial settings may be rated for 240 volts or higher, and circuit breakers for appliances such as electric stoves or dryers may be rated for higher amperages.
The specific voltage and amperage rating of a circuit breaker will be determined by the application and the manufacturer’s specifications.
Here is a table of some common circuit breaker voltage and amperage ratings:
| Voltage | Amperage |
| 120 volts | 15 amps |
| 120 volts | 20 amps |
| 240 volts | 20 amps |
| 240 volts | 30 amps |
| 480 volts | 60 amps |
It is important to note that the amperage rating of a circuit breaker is not the same as the maximum current that can be drawn from the circuit.
The maximum current that can be drawn from a circuit is determined by the capacity of the wiring and the breaker’s trip point. The trip point is the amperage the breaker will trip, usually set at 80% of the breaker’s rating.
For example, a 15-amp circuit breaker has a trip point of 12 amps. This means that the breaker will trip if the current flowing through the circuit exceeds 12 amps.
It is important to never overload a circuit breaker. Overloading a circuit breaker can cause it to trip, interrupting power to the appliances and devices on the circuit. It can also damage the wiring and create a fire hazard.
If you are unsure of the voltage or amperage rating of a circuit breaker, it is always best to consult with an electrician.
What Can Cause A Circuit Breaker To Trip?
There are a few things that can cause a circuit breaker to trip. Here are the most common reasons:
- Circuit Overload. When too many appliances or devices are plugged into a single circuit, or a device is somehow faulty, it can draw too much current, which can cause the circuit breaker to trip. This is a very common cause of an overload.
- Short circuit. A short circuit is a direct electrical connection between the hot and neutral wires. Damage to the insulation that coats the wires, as well as loose connections, can cause the circuit to short. A short circuit will cause a large amount of current to flow, which will trip the circuit breaker.
- Ground fault. A ground fault is a path for current to flow to ground that is not through the intended circuit. A ground fault will also cause a large amount of current to flow, which will trip the circuit breaker.
- Faulty circuit breaker. In rare cases, the circuit breaker itself can be faulty and trip even when there is no overload or fault. This is usually due to a manufacturing defect or damage.
If your circuit breaker keeps tripping, it is important to identify the cause of the problem so that it can be fixed. If you are uncomfortable troubleshooting electrical problems, it is best to call an electrician.
Here are some things you can do to prevent your circuit breaker from tripping:
- Do not overload the circuits.
- Make sure that the appliances and devices you are using are properly rated for the circuit.
- Inspect the wiring regularly for any signs of damage or wear.
- Have your circuit breakers checked and replaced regularly by a qualified electrician.
What Amp Should A Circuit Breaker Be For A Table Saw?
The amp rating of the circuit breaker for a table saw should be at least 15 amps. Most table saws draw between 10 and 15 amps of current. If the circuit breaker is not rated for enough current, it will trip to prevent the circuit from overheating.
However, it is also recommended to use a 20-amp circuit breaker for a table saw. This is because a 20-amp circuit breaker will provide more headroom for the table saw to draw current, especially when the saw is under heavy load. This will help to prevent the circuit breaker from tripping unexpectedly.
Here are some things to keep in mind when choosing a circuit breaker for a table saw:
- The amperage rating of the table saw.
- The number of other appliances that will be on the same circuit.
- The type of wiring used in the circuit.
It is important to consult with an electrician if you are unsure what amp rating of circuit breaker to use for your table saw.
Here are some additional safety tips for using a table saw:
- Always wear safety glasses when using a table saw.
- Make sure that the saw is properly grounded.
- Do not overload the circuit.
- Inspect the saw regularly for any signs of damage or wear.
- Keep the saw clean and free of debris.
- Use the saw properly.
By following these safety tips, you can help prevent accidents and injuries when using a table saw.
What Could Be Wrong With A Table Saw That Keeps Tripping A Circuit Breaker?
There are a few things that could be wrong with a table saw that keeps tripping a circuit breaker. Here are some of the most common causes:
- Overloading the circuit. If the table saw is drawing too much current for the breaker to handle, it will trip. This can happen if the saw is plugged into an outlet that is not properly rated or if the saw is not properly maintained. Included in proper maintenance is proper use – no dull blades, not using a wrong blade, making sure the motor vents are not clogged with dust, the belt is in good shape, switch is proper and not loose, and so on.
- Short circuit. A short circuit is a direct electrical connection between the hot and neutral wires. This can cause a large amount of current to flow, which can trip the breaker. A short circuit can be caused by damaged insulation, loose connections, or faulty components.
- Ground fault. A ground fault is a path for current to flow to ground that is not through the intended circuit. This can also cause a large amount of current to flow, which can trip the circuit breaker. A ground fault can be caused by damaged insulation, loose connections, or faulty components.
- Faulty motor. If the motor in the table saw is faulty, it can draw too much current and trip the circuit breaker. This can be caused by worn brushes, a bad bearing, or a short circuit in the motor windings. Beyond a circuit overload, these would be the second tier of suspects to be checked.
- Faulty switch. The switch that turns on and off the table saw can also be faulty and cause the circuit breaker to trip. This can happen if the switch is dirty or corroded or if the contacts are worn.
- Power cord issue. From the motor to the switch to the power cord to the extension cord, that’s the path from the circuit breaker that could be contributing to the problem. Fraying along either the power cord or the extension cord or a loose plug can result in a short circuit that can trip the breaker.
If your table saw is tripping the breaker, it is important to identify the cause of the problem so that it can be fixed. If you are not comfortable troubleshooting electrical problems, it is best to call an electrician.
Here are some things you can do to prevent tripping the breaker:
- Make sure that the saw is plugged into a properly rated outlet.
- Do not overload the circuit.
- Use the proper size breaker, one rated for your table saw’s needs, at least a 15 amp breaker, but to be sure, a 20 amp breaker is a better choice.
- Consider a dedicated circuit, one that will service just the table saw.
- Inspect the saw regularly for any signs of damage or wear.
- Keep the saw clean and free of debris.
- Use the saw properly.
By following these tips, you can help prevent your table saw from tripping the circuit breaker and keep yourself safe.
Video On Electrical Panels, Circuit Breaker Boxes, and Breaker Replacement
Once again, This Old House offers good advice and guidance. This time, it’s dealing with a problematic breaker and its replacement.
Electricity can be scary, but a systematic approach in diagnosing this issue can lead to a simple solution in most instances. Just be careful. If you’re doing the fix yourself, don’t forget to turn around 3 times and spit on the ground first.