110v or 220v

[Jerry Cummins]

I moved from Texas to southern Illinois little over a year ago. Sold almost all of my power tools, and now in process of rebuilding. Bought a TSC drill press few months back (which I may take back), used Craftsman table saw 22114, and most recently a used Grizzly dust collector. The one power tool I keep when moving was a vintage 70s Craftsman radial arm saw.

When I bought the radial arm saw, I ran it for awhile on 110 volt. Then I switched to 220v..and it was like a new saw. SUBSTANTIAL difference in how it ran. I was thinking I would be running most everything at 220v if it would run that way. BUT....I read somewhere that today's 220v motors are not the same as vintage 70s, and you will not see the performance gains it's just a matter of managing the amp draw.

SO...my last two purchases can run both at 110 or 220, right now I have them on 110v. Will tools that can run at 220v run better on that setting? Thus far the table saw seems fine on 110v, and haven't a way of measuring what change it would make to the dust collector. I have some wiring to do, but have enough power to run them either way, I just want to determine the most advantageous, before I go through setting up the wiring.

[Prashun Patel]

It's a tricky question. A quick high amp draw when a tool starts up can cause the voltage to temporarily sag. This is why lights dim when the iron comes on. This is not optimal for a motor. But how much long term damage it causes is debatable. On 220, a tool requires half of the amps Vs on 110, so the risk of a sag is lower.

Whether the voltage will sag at all is a function of several things including the resistance of the line. The longer the run and lower the gauge, the more chance it'll happen.

im not a pro, but I have noticed this happened on my jointer. I run it now on 220.

[Dan Friedrichs]

If you're installing new circuits, plan for 220 (you'll get by with thinner wire, which is cheaper!). But an appropriate-sized 110v will work just as well.

When people exclaim how much better their tools work on 220v, what they're generally REALLY saying is: "I installed an appropriately-sized 220V circuit, and this offers better performance than the undersized 110V circuit I was previously using". They assume the voltage change is what improved the performance, when in reality, it probably had more to do with installing a dedicated circuit with correctly-sized wire.

[Lee Schierer]

Though it may seem like "it ran like a new saw" there is no performance advantage between a motor running on 120 versus 240. This is an oft debated topic here and the conclusion always is there is no reason other than undersized or excessively long wiring runs to switch to 240. You do not get more speed, torque or Hp on 240 than you get on 120. Just make sure your wiring runs and circuit breakers are properly sized for the rated current of the motor and it should run just fine on 120. Running on 240 will cost more for plugs and outlets and you get fewer circuits in your panel.

[John McClanahan]

My guess is that the plug, cord and/or switch wasn't up to par for 120V use. The plug is the first place I would look at.

John

[scott spencer]

The interaction between every motor and every circuit is unique, so the debate between 110v and 220v isn't an absolute ....it depends on a large number of variables, which are different with each case. If you've got 220v, there's no harm in running the motors on 220v....there might be some improvement if your 110v circuit isn't fully up to the task, or there might not be a perceivable difference. 110v circuits are more prone to voltage loss because a larger load tends to be drawn from a single supply leg...with 220v, the load is divided, which helps it supply peak demands better during startup and recovery from lugging, which can often give the impression that the saw is running better....the reality is that it's no longer being starved at peak demands, and is running as it should. My 22124 ran noticeably better on 220v, but differences with my GI contractor saw were less noticeable.

If you don't have 220v, it's debatable whether it's worth installing, unless you're having obvious issues with the 110v circuit....lights dimming, slow starts, easy bogging, etc. If you're going to install a circuit anyway, I'd definitely include 220v.

[Erik Loza]

I always tell customers that you can never have enough power in your shop. What if you decide you want a 5hp bandsaw or table saw at some point? Do the 220V if you can.

Just my 2-cents.

Erik Loza
Minimax USA

[Mike Henderson]

Couple of things.

1. A modern 240V motor has very few differences from a 1970's 240V motor. And the differences are mostly improvements, such as better efficiency.
2. People have already posted that there's no difference in power, startup, heat generation, and probably several other characteristics between a 120V and a 240V motor PROVIDED THEY ARE BOTH FED BY AN APPROPRIATE CIRCUIT.
3. One of the primary reasons for leaving certain tools at 120V is that you can move them more easily - you don't have to move your 240V circuit or string long power cords. Any tool below 1.5HP is a good candidate for 120V operation.

Mike

[Phil Thien]

I'm no motor expert, but I saw a motor the other day that was interesting. At 120V, it drew (let's say) 15 amps. At 240V, it drew 10 amps. So where you'd expect it to draw 7.5 amps, it drew more. It must have had additional windings being used at 240? So I wonder if any old-time motors were like this?

[Mike Henderson]

I'm no motor expert, but I saw a motor the other day that was interesting. At 120V, it drew (let's say) 15 amps. At 240V, it drew 10 amps. So where you'd expect it to draw 7.5 amps, it drew more. It must have had additional windings being used at 240? So I wonder if any old-time motors were like this?
If it was a new motor, it may have had current limiters that limited the amount of current it could draw at 120V because you can only get so much out of most 120V circuits. What you should also see is that the HP is greater at 240V than at 120V if that is the situation. One of the Nova lathes, for example, works that way.

I never heard of any old motors that worked that way.

Mike

[Rich Engelhardt]

When people exclaim how much better their tools work on 220v, what they're generally REALLY saying is: "I installed an appropriately-sized 220V circuit, and this offers better performance than the undersized 110V circuit I was previously using".
That just might be the most astute observation I've seen/heard in the last who knows how many years.

[Jacob Reverb]

After switching my Powermatic 64 table saw from 110V to 220V, I noticed the following differences:

1. The saw blade spins up to speed much faster on 220V. It's got more "snap" when you throw the switch.

2. Wired to run on 220V, it never throws breakers in the winter anymore. Previously, when it was wired 110V, when it was really cold, it would often throw the 15 or 20A breaker, I guess because the oil or grease in the motor was stiff and there was some resistance on spinup. Now, it draws 7.5A while running, and probably nowhere near 20A on startup. This is not an advantage of 220V per se, but a function of the amperage load being halved on an equivalent-ampacity but double-the-voltage circuit.

[Keith Hankins]

Boy, I've been in so many conversations on 110 .vs. 220 and they can get interesting. First, if you want, PM me, I have a great article on 220 .vs. 110 that goes from basics to the end in laymens terms.

You don't get more power at 220. Remember volts x amps = Watts if you are (simplified) 110v x 10A = 1100 watts. That same motor at 220v would be 220v x 5A = 1100W. You don't gain power or anything it's not cheaper, because you pay based on KWH. Where there is a difference is amps/leg pulled. In 220 you have two hots so that amp is pulled across both main legs of your power source. It lowers the amount of current and pulled and the farther away from the source the more heat can be generated and heat can be a killer to a motor. You can run higher (thinner) guage wire and it helps balance the loads on your main lines (L1 L2). Think about it, a 20A 220 line would be 40a at 110, that takes a lot of copper to carry without heating up. Another big component is that start-up voltage and the more current pull. Anyway, if you want the article ping me, i'll send it to you its a pdf. I've started using 3 phase now (another whole topic) :) Have a good one.

[Mike Henderson]

... In 220 you have two hots so that amp is pulled across both main legs of your power source. It lowers the amount of current and pulled and the farther away from the source the more heat can be generated and heat can be a killer to a motor.

Just to clarify. No matter what the voltage, for single phase power, you have two wires and the current goes through both. People get confused because in our single phase distribution network, the power is supplied with a center tap transformer and the center tap is grounded. To get 120V you go from one of the outside wires on the transformer to the center tap. To get 240V, you go from the two outside wires on the transformer. The fact that the center tap is grounded in no way affects the current flow in the wires - it's just a safety technique.

So if you're pulling 20 amps at 120V, the current flows in the wire that comes from the outside of the transformer AND in the wire that comes from the center tap of the transformer (usually the black and white wires in our system).


If you're pulling 20 amps at 240V, the current flows in the wire that comes from one side of the transformer AND in the wire that comes from the other side of the transformer.

In all cases, you need two wires to complete the circuit and the same current flows in both wires.

Also, there's no difference in heat generated in the motor between 120V operation and 220V operation. There could be a difference in the supply wire, if the same gauge wire is used for 120V operation and 240V operation. But for a supply circuit of the proper size - one that can deliver the proper voltage to the motor when it's under load - this will not be an issue. If the supply circuit is too small for operation at 120V, you will experience a voltage drop across the supply circuit wire, which may cause the motor to be supplied with insufficient voltage when under load. In this case, the motor can draw excessive current and generate greater heat. But for motors supplied with proper supply circuits, there is no difference in heat generation between 120V operation and 240V operation.

Mike

[scott spencer]

To add to Mike's excellent detail, I'd hazard a guess that it's far more common to find a 110v (aka 120v) circuit that's not fully capable of meeting peak demand due to voltage loss than a 220v circuit, so the extra heat drawn from excessive current flow is more likely to occur when wired with 110v than with 220v.

[Joseph Tarantino]

.....You don't get more power at 220......

there is one proviso to this statement. there are some motors that develope more hp @ 220v than @ 110v. this will be stated on the motor's data plate. as for 110v vs 220v, 220v provides more balanced power distribution by pulling power across both phases (as has been mentioned previoiusly). my shop has a 30A sub panel. i can still safely run my lights, air cleaner, box fan, 3hp unisaw and 1.5hp 50-850 DC and the lights flicker less than when i ran a 110v RAS and a 1hp, 110v delta ap400 DC. "tim the toolman" isn't always the answer.

[Erik Christensen]

My 2 cents -

I put every 110/220 v tool on 220v without exception and every 220v circuit is dedicated to a single tool. I do this for a couple of reasons:

1. each tool is on a breaker sized for just for that tool - no daisy chained tools off a 30 amp circuit. Breakers are there to protect things downstream in case of a fault - if you have a bunch of 5-10 amp tools on a 30 amp breaker all the breaker is protecting is the wire (and your shop/home from fire) and not the tool. Using a $1,000++ tool as a disposable fuse to protect $50 worth of copper wire seems a bit backward to me - but hey it's a free country right?

2. 110 circuits have other stuff on them - auto start dust vacs, other tools, lights, maybe even house appliances in a home shop. Other stuff means less 'head room' and you will more likely trip a breaker; plus some things (like that garage fridge that keeps your tasty micro-brew growler cool) really don't like the voltage dips that starting large induction motors cause.

3. big wood tools have big 220 plugs that are unique and catch the eye - when you have your hands in the TS changing the blade and you think "did I remember to unplug this" you can look at the plug boxes and KNOW that is the plug for this saw and not the drill on the counter next to it

[Mike Henderson]

as for 110v vs 220v, 220v provides more balanced power distribution by pulling power across both phases (as has been mentioned previoiusly).

You do not get "more balanced power distribution by pulling power across both phases" with 240V. 240V power is single phase in our US power distribution system. It is supplied via two wires and there's one sinusoidal waveform across the two wires - exactly the same as across two wires supplying 120V. The ONLY difference is the voltage level.

There are very few motors that supply more HP at 240V than at 120V - they would be very special motors that we are unlikely to encounter in woodworking. The Nova lathe that uses an variable reluctance motor does do this but I'd definitely classify that as a special motor. Standard induction motors labeled as dual voltage will supply the same HP at either voltage WHEN SUPPLIED BY AN APPROPRIATE CIRCUIT.

Mike

[scott spencer]

I've heard that some of older Delta motors supposedly had more windings in 220v than 110v, and thus would produce more power. I've also heard an interesting counter argument that the extra winding theory wasn't true, and that 110v amp ratings on those motors were actually understated to appear more compatible with standard 110v residential wiring, and that the actual was indeed half that of the stated 220v ratings. I can't confirm one way or the other, but have definitely read both stories on the web.....could be nothing more than "internet fact", which may or may not contain actual fact. ;)

[Dan Friedrichs]

You do not get "more balanced power distribution by pulling power across both phases" with 240V. 240V power is single phase in our US power distribution system.

+1. As odd as it is, residential service is actually single phase, despite being two "legs" :)


To clarify the "balancing" issue:
With a typical 200A residential electric service, you have power from two legs (that can source/sink 200A total) and a neutral (which carries any imbalance between the legs). If you hook a 110V, 30A load up, you will source 30A from one leg, sink 30A into the neutral, and source 0A from the other leg. If you hook a 220V 30A load up, you source 30A from one leg, sink 30A into the other leg, and source nothing from the neutral. You get twice the power, but the current draw from any of the wires is the same.

Because the neutral wire only carries the imbalance between the two legs, it doesn't need to be as large, since the average current is lower. This is where the concept of "balancing" a subpanel comes in - it's preferable to distribute 110V loads roughly equally between the legs such that the neutral current is minimized. But the current draw through either of the "hot" legs is the same, whether 220V or 110V (ie - a 30A 110V load draws 30A from one leg and a 30A 220V load draws 30A from one leg).

[Joseph Tarantino]

.........With a typical 200A residential electric service, you have power from two legs (that can source/sink 200A total).......

does that mean each wire delivers 100A for a total of 200A across both wires?

[Joseph Tarantino]

You do not get "more balanced power distribution by pulling power across both phases" with 240V. 240V power is single phase in our US power distribution system. It is supplied via two wires and there's one sinusoidal waveform across the two wires - exactly the same as across two wires supplying 120V. The ONLY difference is the voltage level.

There are very few motors that supply more HP at 240V than at 120V - they would be very special motors that we are unlikely to encounter in woodworking. The Nova lathe that uses an variable reluctance motor does do this but I'd definitely classify that as a special motor. Standard induction motors labeled as dual voltage will supply the same HP at either voltage WHEN SUPPLIED BY AN APPROPRIATE CIRCUIT.

Mike

so my comment that there are motors that do develope more hp in 220v mode vs 110v is correct, is it? i don't believe i made any comments regarding what you refer to as standard induction motors.

[Mike Henderson]

does that mean each wire delivers 100A for a total of 200A across both wires?

With our distribution system, if each wire on the outside of the transformer is delivering 100 amps, then the center tap (grounded) wire is carrying zero amps. And in that situation, the total current in the system is 100 amps.

Let's say that you have two 120V loads connected to your distribution box, each drawing 100 amps. The current in each of the outside wires of the transformer will be 100 amps. The current in the center (white wire) will be zero. The total current through the transformer will be 100 amps.

Mike

[Carl Beckett]

Its been a while, but I have designed dual voltage motors (and also dual frequency) motors from scratch. During the design, there are tradeoffs to be made (how its wound, amount of return flux iron to copper winding window, etc. As I remember it - I COULD choose a local optimum for one voltage level or the other, or I could choose a non-ideal optimum in between.

I believe its technically possible to have a motor designed such that it performs more efficiently at one voltage over the other (and I believe you can choose which, during the design). (will have to dig into my notes to remember the details on just why that is - but I know the return flux path is always at issue - because it affects outside diameter and thus lamination footprint - ie: cost. Almost all motors could benefit from upping the OD)

Having said that - I also believe the main benefits of the higher voltage as stated are correct - having to do with power distribution and marginal transfer lines.

[Bruce Wrenn]

I'm no motor expert, but I saw a motor the other day that was interesting. At 120V, it drew (let's say) 15 amps. At 240V, it drew 10 amps. So where you'd expect it to draw 7.5 amps, it drew more. It must have had additional windings being used at 240? So I wonder if any old-time motors were like this?The motor was DOWN RATED for 120 operation so as to allow the use of a 15 amp plug. Delta has done this for years on their contractor's saws. Same on the 120 volt Uni. Yes, Delta made a 120 volt Uni (I have one.)

[Jerry Cummins]

To add to Mike's excellent detail, I'd hazard a guess that it's far more common to find a 110v (aka 120v) circuit that's not fully capable of meeting peak demand due to voltage loss than a 220v circuit, so the extra heat drawn from excessive current flow is more likely to occur when wired with 110v than with 220v.

After reading all the replies..thanks for the input...I think Scott's reply sum it up. I think I will run all three of my major power tools, table saw, radial arm saw, and dust collector at 220v. The 110 circuits are all 20amp, and support multiple regular outlets and lights. I notice a very slight light dimming turning on either the table saw or dust collector both which run at 110. The radial arm saw is on a dedicated 30amp 220v circuit....and I think I'll put all three on the same circuit. The dust collector is likely to run when either saw is on, but I'll never work both saws at the same time.

The 110/220 amps on each are: table saw 15/7.5 radial 11.9/5.5 dust collector 18/9. The highest amp draw is the dust collector so it my thinking is it will benefit the most being off the 110 circuit. The end result I'll have a dedicated 220v circuit that will run two tools max at any given time.

I still have another 30amp 220v circuit that only has an air compressor on it, but because of it's location, it would add considerably to wiring to use. I also have a 50amp circuit that I have a welder on....and since moving here I have seldom used it all all. Point is I have power left to use.

[Jerry Cummins]

Well, I finally completed the wiring for the 220v circuits. I wired as I mentioned earlier, with the dust collector and both saws on a 30amp circuit. My first test rip with the Craftsman table saw, dust collector running.....it's got a lot more power with the 220v. So be it from a better wired circuit, or the 220 itself, 220v works for me.

[Howard Acheson]

Here's my two cents.

Understanding dual voltage 120/240 volt motors is prefaced by an understanding of how electricity is delivered to a house. Coming in from the pole are three wires consisting of two 120 wires and a common. Voltage measured across the two 120 volt wires will read 240 volts while the voltage read between either 120 volt wire and common will read 120 volts.

All convertable 120/240 motors run on 120 volts internally. There are two coils each running 120 volts and using 1/2 the 120 volt amperage (The coils act as a resistance and split the amperage). All you do when you re-wire the motor to run on 240 is change the wiring connecting of the coils from parallel to series. When wired for 240 volt operation, one 120 volt leg and its associated amperage is routed to each individual coil rather than a single 120 volt line providing 120 volts to both coils. The same voltage and amperage runs through the individual coils no matter how it it wired. It is amperage that creates heat, and because the amperage in each coil is the same for both wiring configuations, there is no difference in the heat produced by either wiring configuation. The motor is perfectly happy with either voltage and doesn't even know you made the change.

The only advantage to re-wiring for 240 is that it reduces the amperage in shop wiring running from the breaker to the wall outlet. This means that the voltage drop in the wiring is lessened. If your wiring is properly sized for the amperage and run length, voltage drop will be minimal and well within the operation range of any good motor. Voltage drop will be almost equal if the wire size is the required size for each different motor amperage. Only if your wiring is inadequate for the higher amperage of 120 volts will the motor run better when you convert it to 240. In this case, upgrading the 120 volt wiring one size and making it a dedicated curcuit, will accomplish the same as installing a 240 volt circuit and wiring the motor for 240.

If a motor is coming up to speed very slowly or is tripping a breaker during start up or when under normal load, you either have other loads on the circuit, or the circuit is undersized for the amperage or the run length. The fixes are: remove the other loads from the circuit or upgrade the circuit. To upgrade the circuit, either rewire with heavier wire and a larger 120 volt breaker, or convert the circuit to 240 volts which has the affect of lowering the wiring amperage draw. Either of these solutions will equally fix the problem. Again, the motor doesn't care and won't perform differently as long as it gets clean power.

[Carl Beckett]

(deleted due to redundancy, was on a mobile device and didn't read the thread carefully)

[Jacob Reverb]

If a motor is coming up to speed very slowly or is tripping a breaker during start up or when under normal load, you either have other loads on the circuit, or the circuit is undersized for the amperage or the run length.

When I had my 1.5 hp TS on a 110V circuit, it would trip frequently on startup in cold weather but never in warm or hot weather.

My theory was that in cold weather, any grease or oil in the motor bearings (as well as any oil/grease in the bearings in the sheaves) would "stiffen up" in cold weather (as would the belt itself) ... and that the resistance caused by this was what upped the current surge and tripped the breaker. But as soon as I ran the saw once, even for a second, that was it – it wouldn't trip the breaker again.

At any rate, after I rewired the motor to run on 220, it didn't happen anymore, since my current draw was halved.

I also like the way the motor spins up to running speed a lot faster on 220. Definitely more "snap" when you turn it on at 220V as opposed to 110V.

[Jerry Cummins]

I also like the way the motor spins up to running speed a lot faster on 220. Definitely more "snap" when you turn it on at 220V as opposed to 110V.

Exactly. Sounds different to.

[Mike Henderson]

One of the only negatives I see for putting tools on 240V is that if you decide to re-arrange your shop, you may have to re-run the 240V circuits. So if a tool doesn't have a big motor in it, I leave it on 120V for the flexibility.

Mike