pro-con 110V 220V

[cwearing]

After having selecting a particular lathe what should be the determining factors in selecting 110 or 220 volt versions?
😕

 

[MichaelMouse]

If you have 240 available, you may choose it. If you have to get it put in, forget it. You can get 1.5 HP out of 120, and that's more than enough to move shavings from the piece to the floor.

 

[n7bsn]

Line Sag..

When you compare a 1.5 HP 110V tool and a 1.5 HP 220V tool, there is something called Line Sag to consider

What that means is, when you apply a load, the 110V motor slows down more then the 220V motor.

Max Power....

You can get 3HP out of a 110V motor, it just takes something like 30amps to do it, not many 30amp 110V motors. So it's easier to get more power out of a 220V powered lathe

Odd bits...

Some (and not many) motors actually make more power on 220V then on 110V. To do this the motor has to be very special. Most 110/220V motors have the same (continuous) power. Of course wired for 220V it would have less "line sag". The only motor I am recalling (right now) that actually makes more power at 220 is the Teknatool Nova DVR-XP. But other, very special, motors would do the same

TTFN
Ralph

 

[Frank F]

Use 220

Given a choice between 110 V and 220 V, choose 220 V for any induction motors above 1 HP. Motors on 110 circuits draw twice the amps as the same motor on a 220 V circuit.

If you have 110V circuits, which I assume you do, and space to add two circuits in your breaker panel, it's easy to add a 220V line.

Ralph is absolutely correct regarding line sag. My table saw had the option to wire the 1.5 HP motor for 110 V which I did. When I turned it on, the lights dimmed and motor took a few seconds to get up to speed. I was told that's bad for the motor. I got a 220 line and everything worked fine.

Special motors like the Teknatool or machines with VFDs may be able to handle the line sag.

Frank

 

[Steve Worcester]

The other thing is most motors with a VFD are using 3 phase motors and the VFD (or some other electrical component in the system) converts the single phase in your shop to 3 phase for the motor. Most of those are 220V (or 240V) input. While you can put a 1.5HP motor on 120V, you would still have to go to a larger than normal 15Amp circuit, and there isn't as much overhead available for inrushes or stalling loads like a catch would have.

 

[David Wilkins]

For what it is worth. I have a dvr xp and originally had it plugged in to 110v no problems no complaints. I moved and had the new shop wired so the lathe could be on 220v while I do notice a small increase in power I thought it was adequate at 110v and better than a 1640 @ 2hp.
Hth

 

[Richard Baker]

By "line sag" assume is meant the voltage drop or voltage loss in the household or shop wiring. For a given wire size the voltage drop will of course double if the current is doubled, thus reducing the voltage available to the lathe, lights, or whatever.

 

[John Torchick]

Voltage

I have been told that the higher voltage is more efficient. However, the cost of installing 220V single phase would be a factor. It can be done as a DIY if you could get the wiring instructions. Not really difficult but be aware of what you are doing! Three phase wiring is a different ball game for an electrician.

 

[Tony Latham]

I just looked out the window of my shop and I see that MY power lines are sagging....😀 hmmmmmm......

(A weak attempt at humor)

I can tell you this: I bought a 120V Jet 1642VS and do not regret getting the 120V version. It's a machine.

TL

 

[John Torchick]

Sagging

Tony, when you get older, more than your power lines start sagging. Have you heard of furniture disease? That's where your chest falls down into your drawers.😉

 

[ray hampton]

Tony, when you get older, more than your power lines start sagging. Have you heard of furniture disease? That's where your chest falls down into your drawers.😉

this will never happen , the stomach is in the way

 

[Bill Boehme]

After having selecting a particular lathe what should be the determining factors in selecting 110 or 220 volt versions?
😕

After you have selected a lathe, the determining factor is the operating voltage requirement of the motor or controller. If you get a Powermatic 3520B, you will need 240 VAC. A Jet 1014 mini requires 120 VAC. Not many lathes are supplied with dual voltage motors. Dual voltage motors are mostly replacement motors.

Despite all of the Internet lore about efficiency and other such stuff, there is zero difference between operating the motor on 120 vs. 240 VAC. Anyone who has wiring in their home where operating a fractional horsepower motor causes any appreciable voltage drop, then there is a really serious wiring problem and a need to get an electrician post haste before the house burns down -- it may be time to upgrade the knob and tube wiring. By the way, the term "fractional horsepower motor" means a motor under about three horsepower that runs on ordinary single phase house wiring.

Generally, these fractional horsepower motors are designed to operate on a 20 Amp branch circuit so motors under 1.5 HP are wired for 120 VAC and those between 1.5 HP and 3 HP are wired for 240 VAC. I have never encountered an AC induction motor in the 2 o 3 HP range that operates on 120 VAC -- and the reason is obvious: a 3 HP motor operating on 120 VAC would need a 40 Amp breaker which also means it would need a dedicated branch circuit.

Finally, in the off chance that your lathe does have a dual voltage motor and it gives you a warm fuzzy to operate it on 240 VAC, then I say, "go for it". It will make your electrician happy and help to stimulate the economy.

By "line sag" assume is meant the voltage drop or voltage loss in the household or shop wiring. For a given wire size the voltage drop will of course double if the current is doubled, thus reducing the voltage available to the lathe, lights, or whatever.

I am just an electrical engineer, so "line sag" is a new term for me, too. However, I figured that there is probably some analogy to the practice of wearing one's britches below the waist in order to show the world one's polka dotted drawers.

 

[robo hippy]

Some things I don't understand here.

How does a 110 volt motor draw twice the amps that the same motor does on 220. I always thought that it still draws the same amperage, but is drawing from two lines instead of one.

Also, I have an old Performax 22/44 drum sander that had a 110 volt 1.5 hp motor, and it was on a dedicated 20 amp circuit. It would bog down continually and trip the overload switch on the motor. I had the motor rewired for 220, and it plows through anything I put under it. The feed belt motor was on the same switch on the machine, and it now has a separate 110 volt line. I wouldn't think the drive motor being separated would make that much difference.

robo hippy

 

[Dave Moore]

Robo, I think it's twice the amps in a single wire.
Running 220 it's the same total amps (for a given horsepower), but now it's divided between two wires.

Like Bill says, a 3HP motor on 110 would need a 40 amp breaker (and likely 10 gauge wire too, for any length of run)). Run it on 220 though and it needs only a 20 amp breaker, and it'll do fine on 12 gauge romex.

I think.
Bill will bust me if that's not right, as he should.

 

[Frank F]

Use 220 - Clarification

FWIW, Here are facts to clarify my earlier post.

1. I'm NOT an electrical engineer.

2. The table saw was a Delta Unisaw purchased in the 80's with a 1.5 HP motor. (Note: I wish I had ponyed up the extra cash and bought the 3 HP motor.) The motor came wired for 230 Volts and instructions to rewire it for 115 Volts, which I did. According to the nameplate on the motor, it draws 19.2 Amps at 115 Volts and 9.2 Amps at 230 Volts.

3. I can't say that I've heard the term "line sag" before, but I assumed it meant a voltage drop given the context of this discussion.

4. When starting the saw wired for 115 V, the lights did dim and motor did take time to get up to speed. The breaker NEVER tripped. Once the saw was up to speed, the lights were normal and the saw worked fine. Additionaly the saw was not on a dedicated 115 circuit. I can't say if a dedicated 115 circuit would have made a difference.
5. I didn't keep the saw wired for 115 long. When I rewired the motor back to 230 and ran it on a new dedicated circuit, the saw started properly and the lights stayed bright.

In almost 25 years in this house, I've not had these problems otherwise and the house hasn't burned down. I still recommend 220 over 110 if you have the option unless you get a Nova DVR. While I have no personal experience on that lathe, I've heard it runs fine on a standard circuit. But of coarse the DVR is not an induction motor. Given the cost a decent 1.5 HP lathe plus accessories, the one time cost for an electrican to add a new line should be minor.

This was my experience. I hope it was helpful.

Good luck,
Frank

 

[Bill Boehme]

FWIW, Here are facts to clarify my earlier post.

1. I'm NOT an electrical engineer.

2. The table saw was a Delta Unisaw purchased in the 80's with a 1.5 HP motor. (Note: I wish I had ponyed up the extra cash and bought the 3 HP motor.) The motor came wired for 230 Volts and instructions to rewire it for 115 Volts, which I did. According to the nameplate on the motor, it draws 19.2 Amps at 115 Volts and 9.2 Amps at 230 Volts.

3. I can't say that I've heard the term "line sag" before, but I assumed it meant a voltage drop given the context of this discussion.

4. When starting the saw wired for 115 V, the lights did dim and motor did take time to get up to speed. The breaker NEVER tripped. Once the saw was up to speed, the lights were normal and the saw worked fine. Additionaly the saw was not on a dedicated 115 circuit. I can't say if a dedicated 115 circuit would have made a difference.
5. I didn't keep the saw wired for 115 long. When I rewired the motor back to 230 and ran it on a new dedicated circuit, the saw started properly and the lights stayed bright.

In almost 25 years in this house, I've not had these problems otherwise and the house hasn't burned down. I still recommend 220 over 110 if you have the option unless you get a Nova DVR. While I have no personal experience on that lathe, I've heard it runs fine on a standard circuit. But of coarse the DVR is not an induction motor. Given the cost a decent 1.5 HP lathe plus accessories, the one time cost for an electrican to add a new line should be minor.

This was my experience. I hope it was helpful.

Good luck,
Frank

Frank, in your case, you were better off running the motor on 240 VAC. A 20 Amp breaker is not enough margin for a nameplate rating of 19.2 Amps. You really needed a 30 Amp breaker if you were going to use 120 VAC. It sounds like some of the lights were on the same circuit. When an AC induction motor starts up, the initial surge can be anywhere from three to six times the nameplate rating. The heavy current surge is the result of accelerating the inertial load of the rotor, drive train and blade to full speed in a fraction of a second. A VFD drive will usually do a slow ramp up in speed to eliminate the heavy start up current surge.

 

[Bill Boehme]

Some things I don't understand here.

How does a 110 volt motor draw twice the amps that the same motor does on 220. I always thought that it still draws the same amperage, but is drawing from two lines instead of one.

Also, I have an old Performax 22/44 drum sander that had a 110 volt 1.5 hp motor, and it was on a dedicated 20 amp circuit. It would bog down continually and trip the overload switch on the motor. I had the motor rewired for 220, and it plows through anything I put under it. The feed belt motor was on the same switch on the machine, and it now has a separate 110 volt line. I wouldn't think the drive motor being separated would make that much difference.

robo hippy

The field winding of a dual voltage motor is split into two halves. If you want to run it on 120 VAC, then you need to connect the jumper wires so that the two halves of the field windings are in parallel. If the motor is operated on 240 VAC, then the jumpers are connected so that the two halves are in series. In either case each set of windings will always have 120 VAC applied across its terminals and will have the same current flowing through it. The only difference is that when in series, you have a voltage divider and when in parallel, you have a current splitter.

A 20 Amp branch circuit was probably not adequate for your motor as evidenced by frequent tripping. Also, a breaker that trips all the time will eventually become weak and trip at a much lower current. That is probably what happened in your case. This is another situation where the Ampacity of the branch circuit was not adequate for the motor and using 240 VAC was the right way to go.

 

[MichaelMouse]

A 20 Amp branch circuit was probably not adequate for your motor as evidenced by frequent tripping. Also, a breaker that trips all the time will eventually become weak and trip at a much lower current. That is probably what happened in your case. This is another situation where the Ampacity of the branch circuit was not adequate for the motor and using 240 VAC was the right way to go.

When the motor bogs, the start capacitor tries to kick start it, and you get a continuous draw similar to the initial overdraw which gets the motor turning. Probably weren't getting the best finish nor the greatest belt life by overfeeding the sander either.

For those who complain about startups dimming the lights - you've violated one of the first principles of wiring by not putting your primary lighting on its own circuit. Makes it a lot easier on the shins to have the lights on as you head to the box after your saw blows a breaker.

 

[Richard Baker]

The basic equation for electric power is that power equals the product of voltage and current (P=E x I). Hence for the same 1.5 horsepower motor, if you double the voltage (E) you only need half the current (I). What Bill said.

 

[n7bsn]

The basic equation for electric power is that power equals the product of voltage and current (P=E x I). Hence for the same 1.5 horsepower motor, if you double the voltage (E) you only need half the current (I). What Bill said.

We have a winner 🙂

Not that the others were wrong, but that's certainly the easy way to explain it

 

[Frank F]

For those who complain about startups dimming the lights - you've violated one of the first principles of wiring by not putting your primary lighting on its own circuit. Makes it a lot easier on the shins to have the lights on as you head to the box after your saw blows a breaker.

I didn't violate any principles of wiring, because I didn't wire the house. A "professional" wired the house long before it became my house. 🙄

 

[Bill Boehme]

When the motor bogs, the start capacitor tries to kick start it, and you get a continuous draw similar to the initial overdraw which gets the motor turning. Probably weren't getting the best finish nor the greatest belt life by overfeeding the sander either.

For those who complain about startups dimming the lights - you've violated one of the first principles of wiring by not putting your primary lighting on its own circuit. Makes it a lot easier on the shins to have the lights on as you head to the box after your saw blows a breaker.

You are right about lighting should not be on a branch circuit with any appliance outlets).

Generally, the centrifugal mechanism will not engage until a motor is almost at complete stall. I guess that I would have to see it to get a better feel for how much "bogging" is going on, but even at 25% of full speed the centrifugal switch on most motors would not kick in. However, a motor that "bogs" that much is well on its way to a full stall and unlikely to recover on its own and probably go to a full stall and engage the start winding and capacitor.

I didn't violate any principles of wiring, because I didn't wire the house. A "professional" wired the house long before it became my house. 🙄

Who knows how "professional" the work was.

 

[Frank F]

Who knows how "professional" the work was.

I guess the sarcasim was missed. Let's just say "Grandfathering" could be used in describing the "professional" work. I am well aware about separating lighting and applicance circuits, but I played the hand I was dealt. So far so good.

Frank

 

[Robert Manning]

I have a question that relates to this discussion.

I know that one horsepower is equal to 746 watts and that volts times amps equals watts. I checked the voltage in my studio with two different digital volt meters and it ranges from 119 to 120 volts.

I am looking at a new single stage compressor that is rated:
3.5 hp
12.8 cfm @ 90 psi
14.5 cfm @ 40 psi
130 psi max
60 gal. vertical

The motor plate states 16 amps and 208-230 volts.

When I multiply my (120 volts x 2 x 16 amps) divided by 746 watts, I get 5.15 hp.

I know there is a percentage factor of inefficiency, but I wonder what my actual hp will be with two 120 volt hot wires. I can minimize voltage drop with, in this case, #10 wire, and the run is short from the sub-panel.

 

[Bill Boehme]

I have a question that relates to this discussion.

I know that one horsepower is equal to 746 watts and that volts times amps equals watts. I checked the voltage in my studio with two different digital volt meters and it ranges from 119 to 120 volts.

I am looking at a new single stage compressor that is rated:
3.5 hp
12.8 cfm @ 90 psi
14.5 cfm @ 40 psi
130 psi max
60 gal. vertical

The motor plate states 16 amps and 208-230 volts.

When I multiply my (120 volts x 2 x 16 amps) divided by 746 watts, I get 5.15 hp.

I know there is a percentage factor of inefficiency, but I wonder what my actual hp will be with two 120 volt hot wires. I can minimize voltage drop with, in this case, #10 wire, and the run is short from the sub-panel.

OK, you have the information to determine the efficiency of the motor: 3.5 HP output mechanical power divided by 5.15 HP input electrical power shows that the efficiency is about 68% which is fairly typical for a single phase induction motor. I am impressed that they are actually being truthful about horsepower.

I am a bit worried about what it sounds like you want to do to get your 240 volts. It sounds like you are saying that you plan on going across the hot leads of two different branch circuits. If that is the case, that would not be a good idea -- not to mention being against code. You might also find that it won't work if the two branch circuits happen to be from the same phase rather than opposite phase. The correct way to do this is to install a new single 240 volt breaker (or two mechanically ganged 120 volt breakers) in the feeder panel that services your studio. If the power is obtained through two separate breakers that are not ganged together mechaniclly, An over-current condition would cause only one of the breakers to trip which would leave you exposed to high voltage still present on the compressor. If the problem were ground fault related, then 120 volts would be present on the exterior metal parts of the compressor. Please tell me that I misinterpreted what you meant.

 

[Robert Manning]

Don't worry, Bill, I know that single phase 240 needs a dedicated circuit with the two 120 legs on the two separate phases which can back-feed to ground alternately at 180 degrees through a common neutral. And that the two poles of the breaker need to trip simultaneously in the event of an overload. And that the breaker needs to be installed in such a way that it accesses both phases.

I wasn't aware that 68% efficiency was in the normal range for an induction motor. Thanks for clearing that up. How are things out your way? Are you going to the symposium?

Best regards,

Robert

 

[Robert Manning]

I am a bit worried about what it sounds like you want to do to get your 240 volts. It sounds like you are saying that you plan on going across the hot leads of two different branch circuits.

Were you having some sort of a fantasy?

 

[Bill Boehme]

Were you having some sort of a fantasy?

I have a couple friends who cheaped out and did just that to get 240 volts. They knew that it could be done and are a bit scornful of regulations as being nothing more than an inconvenience. There are safety implications that may not always be obvious.

 

[John Torchick]

Electrical stuff

I'm not an electrical engineer either but I stayed at a Motel 6 once.😀

 

[Bill Turpin]

HP is usually FRAUD!

Robert:
Most manufacturers lie about horsepower. They list breakdown or "just before burn up horsepower" because our gov'ment lets them. A true 1 HP motor pulls ± 12 amps on 120 vac. So how can we have 3.25 HP routers and 7 HP vacuum cleaners on house current with 20 amp circuits? The NEC and UL should stop these deceptive practices! Does the UL do anything more than collect their licensing fees? When was the last time that you bought a super dupper appliance/tool with a number 12 cord, no, they are 14 or 16 or 18.

 

[Bill Boehme]

Robert:
Most manufacturers lie about horsepower. They list breakdown or "just before burn up horsepower" because our gov'ment lets them. A true 1 HP motor pulls �± 12 amps on 120 vac. So how can we have 3.25 HP routers and 7 HP vacuum cleaners on house current with 20 amp circuits? The NEC and UL should stop these deceptive practices! Does the UL do anything more than collect their licensing fees? When was the last time that you bought a super dupper appliance/tool with a number 12 cord, no, they are 14 or 16 or 18.

For motors that are an integral part of a hand tool (such as the motor in a drill, sander, or jig saw) horsepower ratings aren't really applicable. Generally, small hand power tools and lightweight appliances use universal motors which are basically low power DC motors where the speed and power are both variables that depend on the voltage and load torque. Stating horsepower for these motors is mostly an exercise in wasting time because the actual power is small and for the stated power to mean anything, all of the operating conditions would need to be given. You are correct in mildly hinting that perhaps some shenanigans are sometimes employed in creatively stating horsepower, but this mainly applies to tools where the universal motor is an integral part and should not be interpreted as something that is applicable to all motors.

Horsepower is not even mentioned for most small hand power tools except for routers. I seem to recall that the "router HP wars" got revved up in the late 70's when marketing one-upmanship hype replaced actual performance.

The nameplate ratings given on AC induction motors are accurate and don't "play" with the laws of physics. A few years ago, the notable exception was the HP ratings claimed on consumer air compressors, but hopefully, a class action settlement has helped to reduce that problem. Memories of that abuse may be the biggest reason that so many of us scoff at horsepower ratings. Other than the above exceptions, if you buy an off-the-shelf AC induction motor you can reasonably assume that the nameplate information is correct.

UL is a non-governmental organization that develops safety testing standards and performs safety testing in 68 laboratories. Products that are certified as safe by their laboratories will carry the applicable mark. They are very restrictive on the ways that a manufacturer may use the mark on a certified device that they tested and approved. You can go to the UL website if you want full details.

The NFPA (National Fire Protection Association) is a fire safety standards organization that maintains and updates numerous fire safety codes and standards. The National Electrical Code (NEC) is a document (not an organization) maintained and updated jointly by the NFPA and UL. Requested changes to the code is an open process that you can learn more about at the UL and NFPA websites. New releases to the NEC are published every three years by the NFPA. The purpose of the NEC and other documents published by the NFPA is fire and electrical safety in order to protect human life. They do not sell or give away "licenses" to endorse anything.

I have some antique radios and an electric drill from the 1920's and feel somewhat knowledgeable about antique electrical devices from that era. I don't recall ever seeing 12 ga. power cord on anything including electric heaters and clothes irons. That is because these devices must all operate on a 15 Amp branch circuit wired with 14 gauge wiring. Appliance cords, being in open air, are subject to less heating than enclosed wiring in a conduit or raceway and, therefore, do not have the same Ampacity ratings as permanent enclosed wiring. I do, however, have an air compressor that has a 12 gauge power cord and a bandsaw with a 10 gauge power cord.