The standard 15A motor table saw will draw approximately 8 to 9 amps on a 120VAC, when it is under no load. In other words, when you turn the saw on with no wood being pushed through the blade, the saw will draw a continuous 8 to 9 amps.
Most entry to mid-level model table saws utilize a universal motor, which draws an initial surge in power to get running and then quickly settles around the 8 to 9 amp window.
Here you can see the initial spike shortly after the saw was turned on.
Here is the continuous draw of 8.65A at 114.1V.
If your saw is connected to a 220V circuit, the amp draw will be half of what is on a 120V circuit. Almost every table saw you see at your local home improvement store will not have the capability to be wired for 220V. However, most higher-end, contractor and professional saws have the ability to be wired in either 120v or 220v.
For example, SawStop’s Professional Cabinet Saw with a 1.75HP motor is wired to a default 120V setup at 14A. An optional kit can be purchased to run the saw on 220V. Thus, if on a 120V circuit, it has a no load draw of 8-9 amps, on a 220V circuit, the no load draw would be halved and somewhere in the range of 4-4.5 amps.
How many watts does a table saw use?
Because we have our no load continuous amp measurement, we can estimate the no load watts at around 900 to 1000 watts. To calculate watts, we take the amp draw times the voltage to get watts. In our test measurements above, we measured an amp draw of about 8 to 9 amps that were running on 114 volts.
Do I have sufficient power for my table saw?
It varies from home to home, but for a typical 15A table saw on a 15A circuit, as long as your table saw is the only electronic item drawing significant power, you’ll be fine. If there is anything like a shop-vac, other power tools, anything that generates heat (space heater), or has a motor (vacuum cleaner), then you may run into some issues.
The general rule of thumb is that a circuit should not exceed 80% of its capacity. In other words, for a 15A circuit, you do not want to be continuously pulling more than 12A (15 x 0.80). For a 20A circuit, no more than 16A.
This also includes other items that are not directly connected to the wall outlets, but may run on the same circuit. For example, your garage door opener, garage lights, and outdoor driveway lights may all be on the garage’s circuit.
The easiest way to determine what is or is not on the circuit is to flip the breaker and find out what’s still working.
If your electrical panel has open slots, you have the ability to add additional circuit breakers, but you will need to check to see if your home has enough capacity for it all. Most newer homes in the United States have 200A service, meaning 200A total for the entire house to use. Consult with an electrician in your area before installing additional breakers to the box.
What type of extension cord do I need for a table saw?
For a, up to 15A, table saw you’ll need at least a 12AWG (12 Gauge) extension cord for any length less than 50 feet. For anything greater than 50 feet, you’ll want to size up to a 10AWG (10 Gauge) extension cord to account for the voltage drop over the length of the cord.
Using your table saw with an extension cord that isn’t rated for the amount of power the cord is carrying can damage the table saw’s electrical components and motor and put you at risk of a fire. The cord may not be able to handle the heat of the current and can melt.
15A vs. 20A Breaker
A 15A, 14A, 13A, or 10A table saw will run on either a 15A or 20A breaker. The power draw that is advertised for the table saw’s motor is not its continuous amp draw, but often what its peak continuous draw is, although this varies from manufacturer to manufacturer.
Most homes in the United States have 15A breakers standard throughout the home, including the garage. You will not have any trouble running the table saw on this circuit, as long as there are not any other appliances or tools drawing significant power on the same circuit.
For example, all the outlets in your garage are likely connected and labeled under a single breaker in your electrical box. All of these outlets can run a collective 15A (or whatever the breaker size is) continuously before it’s tripped - meaning you have to turn everything off, then go flip the switch to reset the circuit breaker.
If you’re running a shop vac for dust collection on the same circuit as your table saw, this will certainly put you at risk of tripping your 15A circuit breaker. Most vacuums also use a universal motor that draws somewhere between 4-8 amps of power continuously.
The Type of Circuit Breaker Matters Too
There are four types of circuit breaker technology in-use today, and those are:
- Magnetic
- Thermal-Magnetic
- Thermal
- Magnetic-Hydraulic
According to ETA Engineering Technology, each of these circuit breakers has a different trip profile in relation to time and current, and each has distinct mechanical characteristics.
The one that is most likely in your home is a thermal-magnetic circuit breaker. These work by assessing the heat that’s generated as the current passes through the breaker. If the breaker gets too warm, the breaker will trip and shut off the circuit. This is a bit of an oversimplification of the process, but the takeaway concept is more current, generates more heat and when there’s too much heat, the breaker will trip.
Because of the way these breakers work, you can have a high initial amp draw for a very short period, even above 15A on a 15A circuit, and not immediately trip the breaker.