More money to run 220 0r110

[Darin Higginbotham]

Does it cost more to run a dual voltage motor at 220 rather than110.

[Rick Pettit]

Pulls fewer amps at 240 volts.

[Mike Davis NC]

Does a gallon of water cost more if it comes in through one pipe or two?

No difference.

[Dan Friedrichs]

Pulls fewer amps at 240 volts.

But the power company bills you for power, not amps, and power is volts times amps. So, yes, it pulls half the amps, but at twice the voltage, for the exact same power.

So: no. Same cost, either way.

[Jason White]

Ditto what Dan said. What you pay is based on total watts (kilowatt hours) used.

That said, your motor will start faster and run cooler on 220 volts -- at least in my own personal experience.

Jason



But the power company bills you for power, not amps, and power is volts times amps. So, yes, it pulls half the amps, but at twice the voltage, for the exact same power.

So: no. Same cost, either way.

[Dan Friedrichs]

That said, your motor will start faster and run cooler on 220 volts -- at least in my own personal experience.



Well, for the same size wire running to the outlet, yes, the motor will start faster on 220V (because there will be less voltage drop across the length of the wire).

The motor will NOT run hotter at 110V. When you re-wire a multi-voltage motor, you just change some windings within the motor from being in parallel to being in series. The motor has no idea if the wire supplying it is 110 or 220V.

[Rod Sheridan]

As others have said, the motor uses the same power, so you're billed the same from the utility company.

As to performance on 120 VS 240 volts, if there's a difference you have a circuit design problem.

Regards, Rod.

[Kent Chasson]

Sorry to hijack but a kind-of related question for the electrician/physicists. Does the total heat output of a machine correlate directly to electricity input? My new dust collector really heats up the shop and I'm wondering if it's pulling massive amounts of electricity or if something else is going on.

[John Coloccia]

Sorry to hijack but a kind-of related question for the electrician/physicists. Does the total heat output of a machine correlate directly to electricity input? My new dust collector really heats up the shop and I'm wondering if it's pulling massive amounts of electricity or if something else is going on.

Do you have any idea what a deep and fundamental question you just asked? I'll bet you that you can go to 10 different physicists and get at least 2 completely different answers. I'm interested in seeing what the answers to this end up being!

[Mike Schuch]

Hopefully the vast majority of the work your dust collector is doing is sucking air not heating it. I think that you probably could correlate the heat output of a motor to its efficiency. A motor that is 80% efficient will use less electricity to do the same job as a motor that is 60% efficient. Where does that extra electricity go in the 60% efficient motor?..... HEAT!

[Dan Friedrichs]

You're not even going to take a stab at it, John? :)

The total energy (electrical) provided to the DC does eventually get turned into heat (all of it). Conservation of energy tells us that no energy can be "destroyed". If you have a 5HP dust collector that is running near the motor's full capacity, you are drawing roughly 4kW, and all of that energy will get turned into heat. Consider that even moving air around takes energy to do, and when that moving air runs into something (a wall, etc), the kinetic energy it contained has to go somewhere (in this case, it heats up the wall).

Interestingly, if you had a very well-sealed shop (ie - no light, sound, vibration, air, etc, could escape), you could turn on a 4kW dust collector or a 4kW electric heater, and have the shop heated the exact same amount*.

(*that said, you might find the electric heater makes the shop more comfortable because it heats the air, rather than, say, the walls, but the principle still holds - whatever electric energy you brought into the shop must be turned into some other form of energy, because it cannot be destroyed)


All that said, if you are concerned that your DC is drawing too much power, you could get a cheap clamp-on AC ammeter and check how much current it is drawing, and compare to the nameplate.

[Dennis Ford]

I am not a physicists and did not stay at Holiday Inn last night. As Mike wrote, most of the energy is used to move air around, and some is directly output as heat. But the moving air eventually converts its energy to heat also. In a closed shop the dust collector will convert virtually all of the input energy to heat.

[Rod Sheridan]

All the electricity your motor is using will be converted to heat.

If you don't exhaust the air outside from your dust collector, you will be heating your shop with the full electrical load of the motor.

This is also true for all lighting and power tools.

So if you're running a dust collector whose motor is doing 2 HP of work and the motor efficiency is 85% you'll have

2 HP X 746 w/Hp X 1.15 = 1,716 watts

Most people don't think about that, however all machine losses such as friction and windage are converted to heat, as is the work required to cut the wood. (That's why the sawdust is hot, the 1 HP of work the saw blade is doing is heating the wood and the saw dust produced).

Fortunately for hobby users, the only machine that does any real work is the dust collector, the saw sits there idling then you make 10 seconds of a cut at 3/4 HP then it sits there idling while you pick up the next piece etc.

If you've ever had experiences running molders or gang rip saws in industry you're familiar with how much heat is carried away by the chips and dust.

Regards, Rod.

[Chip Lindley]

What They Said! I am NO electrician/physicist, but I AM an expert/amateur! lol!

Dust collector motors run at near their maximum rated amperage all the time. They are heavily loaded, and create much heat from the hard work being done moving massive amounts of air. Dust collector motors are generally TEFC-type, which run hotter than open drip-proof motors.

Many other machines never come close to being loaded that heavily, except for short periods of time. For that very reason, most Industrial machines are overpowered with larger motors than needed. The motor works less, lasts much longer, and probably does not consume more watts working at 66% capacity, than a smaller motor would consume at 100% capacity. That power consumption could easily be measured by instruments.

To the OP's question: No difference, if both 110v and 220v circuits are sized adequately and within length guidelines. But, too often, 110v machines are run on undersized extension cords that get warm to the touch. That is energy wasted as resistance. All other things being equal, energy to run the same machine on 220v would cost LESS.

[Carroll Courtney]

Here in and around the Houston area the companys are changing out the old style meter to what is called "Smart Meter" which is digital and not the rotating disk type and now it will cost you more to use 220v vs 110v which is base on what the elec companys considers the best for them either KWhrs,voltages,amps,etc it makes no difference.Wish I would have paid closer attention and provided a better answer.Only thing that happens is on 220v your just using up another space for a breaker and your limiting yourself on outlets.This info is not from me but from an elec.class that I took afew days ago from Wayne Rogers who is an electrical consultant----Carroll

[Josiah Bartlett]

I doubt you run your machines enough to ever see the difference in energy cost between running them at 120V versus 240V. If you did, you would probably have switched over to 3 phase.

However, you have to think of the other costs involved- a 240V breaker costs twice as much as a 120V breaker because it has two poles, and takes twice as much panel space. 240V plugs and receptacles are expensive. You need two pole switches. There is the labor involved in rewiring the motor. I don't think it really ever pays off. I have several 240 volt tools, but they are only that way if they are more than 2hp. I don't bother to rewire sub-2 HP machines.

[Dan Friedrichs]

Here in and around the Houston area the companys are changing out the old style meter to what is called "Smart Meter" which is digital and not the rotating disk type and now it will cost you more to use 220v vs 110v

Sorry, but this is absolutely untrue.

Many locales are replacing analog meters with digital meters for several reasons, including the ability to charge higher rates during peak periods, provide for net metering for households which have PV installations, and read meters wirelessly.

It is simply nonsensical to think that 220V would cost more than 110V. One can easily be transformed into the other. You always pay for Watts, not volts or amps.

[John Coloccia]

You're not even going to take a stab at it, John?


I'm just curious what everyone comes up with. It really is a pretty fundamental question :)

[Kent Chasson]

Thanks for all the replies. John's answer about friction, etc. was mostly what I was asking about. That's what I've always assumed but I've never confirmed it. I'll check the amp rating on the motor and maybe test it with a meter while it's running. It puts out more heat than my heater. Kind of a problem....and it's still winter!

[Mike OMelia]

If a dust collector motor was 100% efficient, then it would contribute no heat to the environment. But the fan connected to such a motor does work (on the air) which will eventually dissipate in the form of heat. You know this is true if you own an air compressor with an intercooler. The amount of heat added in this case is the derived from the additional power draw required to turn the fan (and move the air). Now, add in the fact that motors are not 100% efficient and you get the TWO components that add heat to the environment.

Mike

[Kent Chasson]

If a dust collector motor was 100% efficient, then it would contribute no heat to the environment. But the fan connected to such a motor does work (on the air) which will eventually dissipate in the form of heat. You know this is true if you own an air compressor with an intercooler. The amount of heat added in this case is the derived from the additional power draw required to turn the fan (and move the air). Now, add in the fact that motors are not 100% efficient and you get the TWO components that add heat to the environment.

Mike

Not sure I get you there. Unless by "the environment", you mean "the universe" and then I think we get into into the discussion that John was trying to avoid.:D

Any time any electricity gets used to do work, it is converted into heat, no?

[glenn bradley]

As a wise man told me once upon a time; watts is watts and that's what you pay for.

[Tom Cornish]

Sorry to hijack but a kind-of related question for the electrician/physicists. Does the total heat output of a machine correlate directly to electricity input? My new dust collector really heats up the shop and I'm wondering if it's pulling massive amounts of electricity or if something else is going on.
As others have said, it all goes eventually to heat.

A lightbulb creates heat plus visible light, but put in a box, the light would hit the walls and be converted to heat. An electric motor produces heat plus mechanical energy, but put whatever that mechanical energy does in a box, and it will ultimately turn back into heat from friction or other excitation of stuff. Everything's a heater in the end - if you can get some other kind of work out of your heater before it turns into heat, so much the better.

[Chip Lindley]

I doubt you run your machines enough to ever see the difference in energy cost between running them at 120V versus 240V. If you did, you would probably have switched over to 3 phase.

However, you have to think of the other costs involved- a 240V breaker costs twice as much as a 120V breaker because it has two poles, and takes twice as much panel space. 240V plugs and receptacles are expensive. You need two pole switches. There is the labor involved in rewiring the motor. I don't think it really ever pays off. I have several 240 volt tools, but they are only that way if they are more than 2hp. I don't bother to rewire sub-2 HP machines.

3-phase from the power company is not a viable option. Call your local Utility Company and get a ballpark figure for running a line into your shop. Astronomical! Many smaller shops unhook from commercial 3-phase power because of the hefty "minimum" charged by the Utility, whether any power is consumed or not! Those shops opt for large RPCs to power their 3-ph machinery. THEN, they may actually save some money, because each 3-ph motor running, generates some current into the system. Example: my 7.5hp-rated RPC to run 22 hp. total, if motors are started one at a time.

Excessive 240V costs? In my isolated case, I have one paltry 120v circuit serving my shop space (as most garages do). Wall outlets share the 15A circuit with overhead lighting, plus some outdoor lighting and a garage door opener. Anything plugged into outlets and running, siphons off amps. Under these conditions, I constantly tripped the breaker during hard cuts on my 15A/120V contractor saw. It was a real PITA! On 240V it ran like a Champ!

240V "costs" are not necessisarily double those of 120V. Not if you shop around! When I ran a 100A branch box to my garage to gain 240V service, I counted all costs as gain! I bought most of my wiring stuff at equipment auctions. I got great bargains on L6-30 receptacles and plugs on eBay. I do not pay BORG prices except in an emergency. With only two exceptions, all my motors run on 240V mainly to free up my 120V circuit for those things that require 120V--lighting, a big shop fan, corded hand tools, battery chargers, portable compressor, boom box, etc. etc.

IF I were wiring a brand new shop building (I'm not that blessed yet) I would plan a little differently, but, not much.

[Mike OMelia]

Not sure I get you there. Unless by "the environment", you mean "the universe" and then I think we get into into the discussion that John was trying to avoid.:D

Any time any electricity gets used to do work, it is converted into heat, no?

Not if what it is using it is 100% efficient. But we are talking about motors and there is that nasty "back emf" problem, so you might be correct. The whole space-time continuem thing is beyond the scope of this thread (and my head).

Edit: I'm stepping out on the plank now... very little hope left for me. But if a motor was 100% efficient, then it would only take an initial draw of current to set it spinning. (remember those superconductor ceramic blocks spinning (levitated) in a magnetic field?) Apparently, if IRC, only one thing that slows it down... air. Not even eddy currents (induced by the magnetic field) since it is a superconductor. So, it could be considered a 100% efficient motor. Since it ony takes an initial impulse to get it going (the 100% efficient motor), no new power is being drawn to keep it going. It would be interesting to see one of these blocks spin in a vacuum and see if it slows down. Anyways, such a motor might still generate a "back emf" signal in the coils, but since there is no need for a power connection, that current does not flow. Thus, no work (to convert into heat) is done. But of course, hook a fan to it, then it does work on the air. And it will slow down to zero. The stored energy in the motor is then eventually converted into heat in the air.

The Apollo space program provides a good example. Once the transit vehicle reached escape velocity, it continued on towards the moon without additional energy. It was a "linear" motor. In the vacuum of space. It is about as near to 100% effcient as you can get. It is a perpetual motion device (almost). THis was what I was getting at. Make this motor do new work (change direction) and it will heat up the local environment (the thruster exhaust).

I bet someone jumps on this like a duck on a june bug... what have I done?

[Joe Angrisani]

Mike.... I like your Apollo Anology. But there was significant loss in that "system". They left orbit at around, what, 22,500 mph? By the gravitational midpoint, they had slowed to something like 3,500 mph. Earth sucks. Then the Moon sucked and they accelerated until they fired the motor to brake into lunar orbit.

The (near) vacuum of space is still subject to gravity, even mid-planets or mid-stars or mid-galaxies.

[Mike OMelia]

I knew someone was going to point that out (thus my joke about the space-time continuem and all the unexplained caveats). :)


Mike

[Tony Bilello]

Not sure I get you there. Unless by "the environment", you mean "the universe" and then I think we get into into the discussion that John was trying to avoid.:D

Any time any electricity gets used to do work, it is converted into heat, no?

I agree 100%.
Energy can neither be created nor destroyed BUT and thats a big BUT it can change form. Thats the part you all left out. There are many forms of energy. Light is a form of energy. When a bulb is 80% efficient that means 80% of the electrical energy is converted to light and 20% is converted to heat. With a dust collector, most of the electrical energy is converted to mechanical energy and the rest is converted to heat loss and friction losses in both the motor and the mechanical parts. A battery converts chemical energy into electricity. Solar Energy converts light energy into electrical energy if using a solar cell. Solar energy converts light energy into heat energy if aimed at a water tank or pipes. Water energy, like in moving off a waterfall or in a river can turn a water wheel into mechanical energy to run a mill or it can turn further this mechanical energy into electrical energy by turning a turbine and turn the electrical energy back into mechanical energy when turning your table saw blade. And when you screw up, your project ends up in the firewood pile and is turned into heat energy. Whew!!!!
I'm done for now

Back to the original question.....the total power requirements are the same and the electrical bill would not be affected for all intents and purposes.
Where you would benefit in a home shop would be that if you put in a 220V circuit for your tools, it would not be sharing the same lines with your normal household stuff like lights, fans, etc. The 'not sharing' eliminates the voltage drop across other wires and appliances and your motor will run more efficiently. When I had a home shop in Arkansas, I made a 2 headed extension cord for my 5HP planer and table saw and plugged it into my washer/dryer outlet.

[Dan Friedrichs]

I agree 100%.
Energy can neither be created nor destroyed BUT and thats a big BUT it can change form. Thats the part you all left out. There are many forms of energy. Light is a form of energy. When a bulb is 80% efficient that means 80% of the electrical energy is converted to light and 20% is converted to heat.

...and once that light hits a non-reflective surface, the light energy is also turned into heat. Everything goes to heat, eventually.

[George Bregar]

Man I love these threads. Simple Q: "Does it cost more to run a dual voltage motor at 220 rather than110." Simple A: "No, same cost." But then off to start up advantages, heat produced, panel use efficiencies, Conservation of Energy...all 220 v 110 threads should require the first response to be like a Bud Light commercial..."Here we go!" ;)

[Mike OMelia]

Nobody has mentioned Entropy yet! Thermodynamics can explain all of this. In fact, the entropy of this thread has increased as well.

The real way the OP should have posed the question was does the Earth slow down when he turns on his DC? Does that happen faster on a 220v circuit? If so, he must pay more for that.

[Chip Lindley]

Man I love these threads. Simple Q: "Does it cost more to run a dual voltage motor at 220 rather than110." Simple A: "No, same cost." But then off to start up advantages, heat produced, panel use efficiencies, Conservation of Energy...all 220 v 110 threads should require the first response to be like a Bud Light commercial..."Here we go!" ;)

George, nothing is that simple in Real Life! Too many extenuating circumstances on a case-by-case basis. Thus, the well-worn acronym "YMMV" (Your Mileage May Vary) is alive and well.


Nobody has mentioned Entropy yet!

I think I take a pill for that every day!

[Darius Ferlas]

The dust seems to be settling so let me ask those who know that there is no difference in the cost between 120 and 240Volt - are you sure?

Let's look at the numbers.

Scenario A:

14AWG copper wire
Circuit length: 50 feet
Load: 15amps at 120 Volt
Voltage drop: 4.6V (3.8%)
Voltage at circuit end: 115.4

Scenario b:

14AWG copper wire
Circuit length: 50 feet
Load: 15amps at 240 Volt
Voltage drop: 4.6V (1.9%)
Voltage at circuit end: 235.4

Relevant formula:
Power = Current × Voltage so P = I × V

Let's test the numbers against a machine that runs on either 120V/15Amps or 240/7.5Amps:

Scenario A:
P= 115.4 * 15
P= 1731W

Scenario B:
P= 235.4 * 7.5
P= 1765.5W

If we are to believe that there is no difference in cost of running the same piece of equipment then we'd also have to believe that 1731W=1765.5W. If we need to cut a piece of wood and if the job requires certain amount of energy then it would follow that the resulting energy will be the same for both scenarios. I find this kinda hard to accept. So let's look at the energy generated in each scenario for the same machine running for 5 minutes.

Relevant formula:
Energy = Power × Time so E = P x T or E = I × V x T

1.731 x (5/60) = 0.14425kWh
1.7655 x (5/60) = 0.147125kWh

The difference is ~2% but it will vary depending on circuit lengths, wire gauges etc.

For the scenarios given above, if energy cost is $0.10/kWhr then running a ~1.5HP (1500W) machine for 3.3 hours would save $0.01. If that machine is accompanied a by a dust collector then we're talking some big bucks - $0.02 savings for 3.3 hours of continuous work! In a commercial environment it could translate into a free cup of coffee (small size) each week!

So I would propose that YES - running a machine on a 240V circuit is less expensive than running it on 120Volt circuit :D

Now, since I already stirred the pot and wrath of some forum members is imminent, lemme go on and tell you about stirring another one, where we learn that all energy is ultimately converted to heat. Well, yes and no, the issue is a little trickier than it seems.

A little experiment, grade 6 physics, if I remember correctly.

Pour a quart of clean, tap water into a glass vessel. Pour a table spoon of red clay into the same vessel (color for ease of observation). The clay is insoluble so it will fall to the bottom. Now set the vessel on a kitchen stove, turn the heat on and bring the water to 100deg C (212F). We will see that the clay particles are no longer at the bottom, they move around.

We applied heat and we created kinetic (mechanical) energy. So now I'm lost. Is all energy ultimately converted into heat, or into kinetic energy? Both?

[Dan Friedrichs]

I'm going to reply this bit separately:



Pour a quart of clean, tap water into a glass vessel. Pour a table spoon of red clay into the same vessel (color for ease of observation). The clay is insoluble so it will fall to the bottom. Now set the vessel on a kitchen stove, turn the heat on and bring the water to 100deg C (212F). We will see that the clay particles are no longer at the bottom, they move around.

We applied heat and we created kinetic (mechanical) energy. So now I'm lost. Is all energy ultimately converted into heat, or into kinetic energy? Both?

No one doubts that heat energy can be converted into other forms of energy. But what happens when you remove the source of heat from your clay experiment? The moving clay, containing kinetic energy, experiences friction against the water (and other clay) in the vessel - we all know that friction causes heat. The clay does not continue spinning perpetually - it will come to a stop and settle at the bottom once all of its kinetic energy has been converted to heat energy.

[Dan Friedrichs]

Now for this bit:

The dust seems to be settling so let me ask those who know that there is no difference in the cost between 120 and 240Volt - are you sure?

Let's look at the numbers....


Throughout this thread, we've been talking about a properly sized circuit. In no instance would it be ideal to use 14AWG wire for a load that is either 15A or 7.5A (depending on the voltage used) - if you were installing a new circuit, you would properly size the wire taking into account the length of run and allowable voltage drop. This would result in using a lighter gauge wire for a 240V circuit, which would cause the voltage drop seen across the wire to be much closer to what you'd get with a larger wire and 120V.

Clearly there will be less voltage drop for less current. If you are not installing a new circuit, but are confined to using an existing wire, yes, you may see a very small advantage to using 240V, assuming there is no additional cost for 240V plugs and receptacles and time to convert machines. As your math shows, though, it's not a significant difference (certainly not "twice as expensive" or anything like that).


You also miscalculated the voltage drop at 240V - you used 15A, when the drop should be calculated using 7.5A.

[Chip Lindley]

I prophesy that when the snow melts, gardening begins, fish are biting, and ground is broken for a new shop, threads of this sort will not be nearly as proliferous! ;-)

[Darius Ferlas]

Now for this bit:

Throughout this thread, we've been talking about a properly sized circuit.
The values I used were to show that there is a difference in kW used. I also mentioned that the voltage drops and final usage of power would vary depending on individual parameters and circumstances.


In no instance would it be ideal to use 14AWG wire for a load that is either 15A or 7.5A (depending on the voltage used) - if you were installing a new circuit, you would properly size the wire taking into account the length of run and allowable voltage drop. This would result in using a lighter gauge wire for a 240V circuit, which would cause the voltage drop seen across the wire to be much closer to what you'd get with a larger wire and 120V. .

Circuits are certainly sized to accommodate individual requirements. But it's also true that some circuits end up being either a little under or oversized as new machines and technologies are available. All that doesn't change the final conclusion that given the same circuit size the 240V circuits are more energy efficient, even if only fractionally.

So having recalculated, the difference in Voltage drop is indeed much lower but the ratio of rated Voltage to actual is actually higher (2.5% vs 1%):

Scenario A:

12AWG copper wire
Circuit length: 50 feet
Load: 15amps at 120 Volt
Voltage drop: 2.9V (2.5%)
Voltage at circuit end: 117.1

Scenario B:

14AWG copper wire
Circuit length: 50 feet
Load: 7.5amps at 240 Volt
Voltage drop: 2.4V (1.0%)
Voltage at circuit end: 237.7


You also miscalculated the voltage drop at 240V - you used 15A, when the drop should be calculated using 7.5A.
Good point. Recalculated as above.

[Ole Anderson]

As others have said, it all goes eventually to heat.


I am going to disagree.

Has everyone forgotten the original definition of horsepower? It is the WORK necessary to raise 33,000 pounds one foot in one minute (33,000 ft.-lbs./minute). NOT all of the electricity is being converted to heat, some of it is being converted to WORK in the form of moving air and dust from one place (state of equilibrium) to another.

[Dan Friedrichs]

I am going to disagree.

Has everyone forgotten the original definition of horsepower? It is the WORK necessary to raise 33,000 pounds one foot in one minute (33,000 ft.-lbs./minute). NOT all of the electricity is being converted to heat, some of it is being converted to WORK in the form of moving air and dust from one place (state of equilibrium) to another.

Ole, it eventually ALL goes to heat. Say you use a motor to lift a 33,000 pound block into the air. It took energy to do that - where has the energy gone? It's now stored as POTENTIAL energy in that block. You could hook a rope to the block, tie the rope to a generator, and by dropping the block, pull the rope to spin the generator to make electricity. Or you could just drop the block on the ground, and the energy would be transfered to the ground as heat (while dropping the block once may not immediately seem like it would generate heat, consider what would happen if you took a hammer and pounded something for a long time - eventually it would get hot, confirming that potential energy can be converted to heat).

The energy used by a blower to move air also all eventually goes to heat. Consider what happens: you take 1kWhr of energy and use it to spin a blower which moves air. Does that moving air continue to move forever? Of course not - friction against other air (and objects) will slow it down, turning the kinetic energy of the air into heat. The only alternatives would be to suggest that the air moves forever (clearly, it does not), or the energy disappears (which we know is not physically possible due to the conservation of energy).

[Joe Angrisani]

Doesn't it eventually go to "cold"?

:D

[Mike Cruz]

You are ALL wrong. 220 is WAY cheaper to run. Sorry, I just had to be different... :)

[Ken Fitzgerald]

Mike you are different but your meter measures watts and you'll pay the same regardless......

[John Coloccia]

re: cheaper
Of course, you need to figure in the cost of the double breaker, as well as the costs of the 240V plug and receptacle :p
I don't do large industrial "stuff", but I suspect that plant engineers actually worry about these sorts of things on a large scale where it can be significant.

Joe:
It does all go to "heat" in the sense that all that energy eventually gets given back in the form of agitated molecules bumping into each other (minus some lesser losses due to magnetic flux lines flying off into spacing, supposedly shaking something far away and heating that up instead), but this isn't really fundamental and is more of a consequence. The fundamental part is that we're taking ordered energy (60Hz signal on the wire, for example), and systematically turning it into less and less ordered forms of energy (ultimately a bunch of particles in a more or less uniform state of agitation, bumping into each other) from which we can extract less and less useful work.

And THAT is what's so interesting about this question. Someday, the entire universe will have gotten to the point that no more useful work can be extracted and energy will be distributed more or less uniformly, leaving the Universe a very, very very very very cold place.

So the same fundamental principles that drive everything to heat in my workshop are the same fundamental principles that are driving Universe to a uniform deep freeze as well :)

[Mike Cruz]

Ken, again...no! MY meter reads ounces and pints. :D

[Mike Cruz]

John, I don't get it. Could you create a home video to walk me through it? Say, with a woman in it...full of spirits, I mean spirit. With a lot of giggling. Yeah, giggling helps. :D

[Ken Fitzgerald]

Ken, again...no! MY meter reads ounces and pints. :D

And some day I'd like to help you test your meter............:D

[Marty Paulus]

That's strange. My wife calculates the cost of me doing work the same way...As so several of my friends.

[Andrew Yang]

Wiring/Receptacle Costs
I wired my workshop for 240V for my DC, tablesaw and jointer/planer this past year. I will say that while the receptacle prices are like 8x a standard 120V receptacles it's not a budget breaker. I would hope people can manage $12 versus $1.50. The breaker itself is nominally more but depending on how far your outlets are from the breaker, the wiring itself will likely over ride all the other costs.

Smart Meters
The average home in North America is supplied its electricity using two 120V lines. Utilities implementing Smart Meters are concerned with 1. usage profiling, 2. net usage, 3. remote access to meter data, and 4. commodity theft. It is not possible to distinguish 120V vs 240V usage within the home at the meter. It would be limited to detecting drops in overall voltage levels due to excessive draw. This is different than commercial/industrial metering where the focus is on the complex power, not the apparent power, so it is more typically metered in VA not kWh. The simplest household example of this is the CFL which has an apparent (and rated) power of 11W but a complex power of up to 23W.

Power/Heat
With respect to the comments saying "all" the incoming electricity is turned into heat, it is technically correct, but practically incorrect. It would be like saying all of the energy in the gasoline is turned into heat. Technically it is correct as all energy, as another poster intimated, eventually decays to heat, but the relative efficiency of turning energy into useful work defines what amount is redirected prior the decay. i.e. moving the car or blowing air. In this case, a typical blower will operate at between 60-70% efficiency, meaning that of the electrical energy utilized, 30-40% will be lost through various mechanisms and end up as heat prior to contributing useful work. The balance is put toward useful work before decaying to heat.

edit: the forum is a little wonky in showing replies to replies vs. replies to the thread

[Charlie Velasquez]

I will not address cost of 120 vs. 240. However, my electrician suggested I wire my motors with 220 if possible. He said it better "balances" my leads and I would be less likely to see lights dim or other things on the puny 60A panel in my shop. Have no idea if this is true, but he is a very respected electrician.

[Todd Willhoit]

The values I used were to show that there is a difference in kW used. I also mentioned that the voltage drops and final usage of power would vary depending on individual parameters and circumstances.

In either scenario, as evidenced by the voltage drop, power (I^2*R) is lost in the cable. Using the data provided in your post, the total power consumed is the same, though less is wasted in the cable int the 240V system. Without knowing more about the motor, one cannot tell if the higher load power of the 240V system actually results in more work.

Scenario A:

V(line): 120
A: 15
V(loss): 2.9
R(cable): 0.192 Ohm
P(load): 1756.5
P(cable): 43.5
P(Total): 1800.0


Scenario B:


V(line): 240
A: 7.5
V(loss): 2.4
R(cable): 0.320 Ohm
P(load): 1782.0
P(cable): 18.0
P(Total): 1800.0

[Chris Jackson]

I've run 220 through my shop with 10awg 3 conductor, and 30 amp NEMA twist-lock recptacles...the reality is I will most likely NEVER recoupe the cost of that material in my energy savings. As and engineer who has spent many hours running payback calcs for energy savings projects I'll tell you that in my area where I'm paying in the neighborhood of $0.40 a KWH peak season/peak hours none of my machines is demonstrating a significant savings even over a 3 to 5 year window...just my $0.02

[Bryan Wellman]

I will not address cost of 120 vs. 240. However, my electrician suggested I wire my motors with 220 if possible. He said it better "balances" my leads and I would be less likely to see lights dim or other things on the puny 60A panel in my shop. Have no idea if this is true, but he is a very respected electrician.

A Watt is a Watt is a Watt. Doesn't matter how it's getting to the motor 220/120.... I will say I agree with him to the degree that say you have a motor drawing 15A at 120v. That same motor wired for 240V will draw roughly 7.5A per leg. Thus you are balancing out your panel with the load spread across both vs. one of the two phases.

[Kevin W Johnson]

edit: the forum is a little wonky in showing replies to replies vs. replies to the thread

It has to do with the default forum view that happened with the upgrade. Look just above the post at the top of the page, on the right hand side, you'll see "display" with a down arrow beside it. Click on display, and a selection menu will apear, select "threaded mode", and problem solved. It drove me crazy too, till I discovered that.

[Joseph D'Orazio]

Ken, again...no! MY meter reads ounces and pints. :DHa ha, mine too friend, mine too.

So, just to recap, cause I am greenhorn and all, wattage is wattage and you aint using no more or less on account of a motor being 110 or 220, ¿que no? Less amps being pulled for the larger 220 machines, ¿que no?