110 versus 220

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Blog entry by richgreer posted 02-27-2010 04:08 PM 16255 reads 0 times favorited 11 comments Add to Favorites Watch

Several of the tools in my shop have motors that can be wired for 110 volts or 220 volts. The default from the factory is always 110 volts and that is how I use them.

I am wondering – - Is there an advantage to switching to 220 volts on these machines (TS, BS, jointer and lathe)?

Also – If there is a significant advantage, how hard is it to make the switch?

Thanks in advance for any advice you can share.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

11 comments so far

View Peter Oxley's profile

Peter Oxley

1426 posts in 3875 days

#1 posted 02-27-2010 04:32 PM

You’ll probably get a lot of different opinions about this, so I’ll throw mine in, too. I would leave them 110 unless …
1) You run them all day long: 220 will run a little cooler, which doesn’t make much difference to a casual user, but can have some advantages for someone who is in the shop day in and day out – extended motor life being the primary advantage. Or …
2) You are putting in new outlets anyway: 220 uses half the amperage of 110. This doesn’t save you anything on your power bill, but it means you can run lighter weight wire to the outlet, which saves a little money.

Some people will tell you that 220 will save you tons of money on your power bill. It won’t. If you are running hours at a time, the higher amperage of 110 can cause more heat. The heat is wasted energy produced by electricity, which you are paying for … but you’re talking pennies.

IMHO, the downside to 220 is that there isn’t a 220 outlet everywhere you look, so if you want to change the configuration of your tools, you have to provide 220 to the new locations. There are some electricians on the site, and they can correct me if I’m wrong, but I think code only allows one 220 outlet per circuit. If that’s the case, you have to add a new breaker and run wire back to the breaker box for every new 220 outlet.

-- -- --

View wisno's profile


88 posts in 3011 days

#2 posted 02-27-2010 04:50 PM

In my opinion it better that you keep with 110. This is safer for the peoples
The one thing that make different is that the higher voltage will need smaller size wire. But it almost no significant different between 110 and 220.


View david9951's profile


39 posts in 3161 days

#3 posted 02-27-2010 04:56 PM

I would hook them up to 220 so that you could put more equipment on the same circuit. And I would never run anything less then 12AWG wire in a shop regardless of amperage.

View davidpettinger's profile


661 posts in 3200 days

#4 posted 02-27-2010 05:20 PM

Ok, another country heard from. As stated before, unless you are running these machines 8 to 10 hrs a day, leave them 110. If you have 220 available, then I would connect the most often used (table saw?) to that. A 220 motor won’t load up as bad as a 110 motor because it has more amperage to draw on and is not running near peak draw. Larger diameter wire 10ga to 8ga means the wiring can supply the draw a 220 motor will make under load. Nothing less than 12ga in the rest of the shop for your 110 circuits.

-- Methods are many,Principles are few.Methods change often,Principles never do.

View David Craig's profile

David Craig

2137 posts in 3109 days

#5 posted 02-27-2010 05:26 PM

When it can be wired for both 110/220, you are reaching about the max of the amperage that a machine can run on your circuit at 110. I have dedicated a 110 circuit specifically for my high power tools so I don’t trip a breaker. One machine runs at a time and the amperage is sufficient for my tablesaw, miter saw, etc. I have noticed a large mass of extra wire for the 220 circuit that my stove uses. I might build another outlet off of that so I can have a 220 in the basement. As already noted above, there is no savings to the power bill, just less amp load on the circuit so you can run heavier machines. If you do not trip any breakers and your machines are running at 110 and you do not plan on getting any larger machines, you are probably just fine without the 220.


-- There is little that is simple when it comes to making a simple box.

View Sawdust4Blood's profile


404 posts in 3022 days

#6 posted 02-27-2010 05:39 PM

The secret is the wattage (volts x amps = watts). It absolutely will not save you any money because the motor draws a certain number of watts to run. On a 110 circuit there will be twice the amps as a 220 circuit but the watts will be the same and watts are what determine your electric bill. The advantage is more available total power. Subsequently, you can run more motors at the same time on single circuit or run the motor at a higher load before the breaker trips.

If, for example, you have a problem running a large saw and the dust collector at the same time (which you will obviously want together) because the 110 breaker trips, converting to 220 could resolve that problem. Additionally, if you have a large saw that bogs down under load and trips the breaker, converting it to 220 might resolve that issue (assuming the motor is actually capable of the load in question and that you’re not just overloading the tool). Some people will also tell you that reducing the amperage by increasing the voltage will also allow the motor to run cooler and last longer but I don’t know if there is any real data to validate that much less determine where you would hit the break-even point against the cost of re-wiring your shop.

If you’re not having a problem overloading your existing circuits, IMHO it’s unlikely that you would realize any other sufficient benefit to justify the cost. If you are tripping breakers on a regular basis, you absolutely need to do so kind of wiring upgrade before you burn down your shop and 220 is probably good answer.

-- Greg, Severn MD

View 8iowa's profile


1580 posts in 3761 days

#7 posted 02-27-2010 06:09 PM


Most newer homes today have 200 amp service. This has not always been the case. If you have a home built in the 40’s or 50’s with only 100 amps available, then going to 220V on your shop tools makes sense because the full load amperage will be cut in half, thus avoiding the substantial expense of upgrading to 200 amp service.

There are a lot of tools made today that can operate on the standard 15 amp 110V circuit as long as there is nothing else on that circuit. Typical garages today seldom have more than two 15 amp circuits, and they often share with some of the interior household recepticles. It’s not a good idea to have sensitive electronic equipment on the same line as the motors on your tools. This would be another case where installing a couple of 220V dedicated circuits would be beneficial.

-- "Heaven is North of the Bridge"

View richgreer's profile


4541 posts in 3075 days

#8 posted 02-27-2010 06:13 PM

Thanks for all the advice. As an FYI, I put in a dedicated 110 circuit, wired for 20 amps, for my power tools and I never use more than 1 at a time. I also made certain that my dust collector and air filtration unit are on a separate circuit. Based on what I have read here, I see no need to switch to 220.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

View devnull's profile


30 posts in 3026 days

#9 posted 02-27-2010 06:40 PM

in most dual voltage motors there are
two windings. It is possible to connect the windings either in series
or in parallel. For 120V operation, the windings are connected in
parallel; for 240V operation, the windings are connected in series.

What all of this means is related to E=IR (Ohm’s Law) and the
derivative, P=IE, and the result is half the current used at 240V vs
that used at 120V—however, the power (watts) is the same. The
windings in your motor are thus always seeing 120V so no difference in
efficiency, no change in the electric bill, and no cooler running.

If you have a stiff supply (short run of adequately sized wire) it
won’t make a difference which voltage you run it on. If you
have a 15A run of 50 feet, you would indeed be well served by rewiring
the motor to 240V, if for no other reason than to reduce the effect of
the high current draw (and voltage drop) at startup.

-- __A Clean Desk is a sign of a sick mind.__

View Walt M.'s profile

Walt M.

245 posts in 3010 days

#10 posted 02-27-2010 10:12 PM

Actually I had the same idea for my table saw since I was told it would save me on my power bill and I have a 230volt plug not being used. Thanks for the advice I may end up using the 230 on a dust collector since they will both run at the same time.

View 8iowa's profile


1580 posts in 3761 days

#11 posted 02-28-2010 04:19 PM


You’ve been misinformed. Reconnecting your motors to 220V will not save anything on the power bill. The wattage used will be the same. The advantage of 220V is that the amperage in each specific application will be cut in half, thus saving more total amperage for the rest of things in your everyday life.

-- "Heaven is North of the Bridge"

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