Page 2 of 3 FirstFirst 123 LastLast
Results 16 to 30 of 40

Thread: 220/240 volt advantages?

  1. #16
    Join Date
    Jan 2007
    Location
    New Hampshire
    Posts
    2,796
    Quote Originally Posted by Malcolm Schweizer View Post
    Another way of saying what others have said: to get the same HP as a 220V/20A circuit from 110V, you would need 110V/40A, which just isn’t a thing. Your limit for 110V (or 115V) is usually 15A but could be higher on a 20A dedicated circuit. Although vacuums advertise 6 “peak” horsepower, for example, that’s just a burst at startup. The real horsepower maximum you will get from 110V is around 3.5HP.
    Not sure why you think 120V 40A is not a thing. OK. 40A is almost not a thing. But 120V 50A is. (I'm not sure I would want to deal with it. But it is a thing.)

    Breaker:
    https://www.lowes.com/pd/Square-D-QO...ker/5001496497

    Outlet:
    https://www.lowes.com/pd/Utilitech-B...ial-Rv/3775479

    List of all outlets:
    https://www.generatorjoe.net/html/we...quailplug.html

  2. #17
    Join Date
    Mar 2014
    Location
    Los Angeles
    Posts
    1,356
    For those of you who claim a motor will run cooler / more efficiently at 240 because it uses less amperage can you explain a little deeper, please.

    Because my understanding is that power used is measured in watts.
    Watts is voltage x amperage.
    So 120 V x 10 amps = 1,200 Watts
    and 240 V x 5 amps = 1,200 Watts

    I don't see any difference.

  3. #18
    Join Date
    Jan 2007
    Location
    New Hampshire
    Posts
    2,796
    Quote Originally Posted by Mark Gibney View Post
    For those of you who claim a motor will run cooler / more efficiently at 240 because it uses less amperage can you explain a little deeper, please.

    Because my understanding is that power used is measured in watts.
    Watts is voltage x amperage.
    So 120 V x 10 amps = 1,200 Watts
    and 240 V x 5 amps = 1,200 Watts

    I don't see any difference.
    Efficiency is not power nor wattage.

    Driving force makes a difference. It is similar to driving a nail using a 16oz hammer versus a 8oz hammer. With the lighter hammer the nail has to be hit twice as hard to provide the same force, in doing so efficiency is lost.

    The efficiency difference, the temperature difference, and the startup time are nearly (if not actually) impreceptible to the human senses. The differences are really splitting hairs. Does 70.8% vs 70.2% (made up numbers) really make a difference? The few degrees cooler the motor will run may help the longevity of the motor in the long run, but doubtful it would effect the intermittent use that woodworkers use and run their motors.

    If you want the actual numbers and formulas, I can go dig out my power books from college and get back to you later.
    Last edited by Anthony Whitesell; 04-01-2023 at 10:47 AM.

  4. #19
    Join Date
    Nov 2006
    Location
    NE Ohio
    Posts
    6,983
    Back when I worked at Builder's Square (1986-ish), one of the vice presidents invested a ton of his money in Puma compressors. We (the stores) were forced to close out Campbell Hausfeld and replace them all with made in China Puma compressors.
    I'll never forget the fiasco.

    There was a "wheel barrow" model targeted at contractors and roofers, that was electric and retailed for about 1/3 less than anything else on the market.
    We got a shipment of them in - all wired for 120V - 25amp or 30amp, I can't remember - all I know is that it was so high it would trip the breaker as soon as the switch was thrown.

    Every single one of them we sold came back. None of them we able to run.

    The stores had to eat that loss and to make matters worse, once they were written off to no value, we got more shipped in to take their place.
    My granddad always said, :As one door closes, another opens".
    Wonderful man, terrible cabinet maker...

  5. #20
    Join Date
    Jan 2007
    Location
    New Hampshire
    Posts
    2,796
    Quote Originally Posted by Rich Engelhardt View Post
    Back when I worked at Builder's Square (1986-ish), one of the vice presidents invested a ton of his money in Puma compressors. We (the stores) were forced to close out Campbell Hausfeld and replace them all with made in China Puma compressors.
    I'll never forget the fiasco.

    There was a "wheel barrow" model targeted at contractors and roofers, that was electric and retailed for about 1/3 less than anything else on the market.
    We got a shipment of them in - all wired for 120V - 25amp or 30amp, I can't remember - all I know is that it was so high it would trip the breaker as soon as the switch was thrown.

    Every single one of them we sold came back. None of them we able to run.

    The stores had to eat that loss and to make matters worse, once they were written off to no value, we got more shipped in to take their place.
    What plug did they come with? 5-15 or a 5-30? It would not surprise me if (a) they came with no plug and a 5-15 was added [ie., the wrong plug] or (b) came with a 5-30 and someone made an 5-30 to 5-15 adapter. Either way a portable compressor (especially targetted at field work by contractors) that required a 30A service, was a pretty silly design/machine. IMO.

  6. #21
    Join Date
    Apr 2021
    Location
    Austin, TX
    Posts
    652
    The greatest benefit is that you can now buy used 220v machines and step up from the consumer level equipment. I’ve experienced far less competition for 220v machines than 110v on CL.

  7. #22
    Join Date
    Jul 2007
    Location
    NE OH
    Posts
    2,615
    Quote Originally Posted by Mark Gibney View Post
    For those of you who claim a motor will run cooler / more efficiently at 240 because it uses less amperage can you explain a little deeper, please.

    Because my understanding is that power used is measured in watts.
    Watts is voltage x amperage.
    So 120 V x 10 amps = 1,200 Watts
    and 240 V x 5 amps = 1,200 Watts

    I don't see any difference.
    I don't want to step on any toes, but there is no difference. Inside a standard motor capable of being wired for 120 or 240 are two sets of two coils. For 120 the two coils of each set get wired in parallel in the motor terminal block. For 240 they get wired in series. Each coil sees 120 volts no matter which way it is wired. The same current flows through each coil no matter which way it is wired. There is no difference in losses or efficiency *inside* the motor.

    All of the points made in the thread about being able to run larger motors, using smaller wire, etc, are true, but the motor itself doesn't care or see any difference.
    --I had my patience tested. I'm negative--

  8. #23
    Quote Originally Posted by Mark Gibney View Post
    For those of you who claim a motor will run cooler / more efficiently at 240 because it uses less amperage can you explain a little deeper, please.

    Because my understanding is that power used is measured in watts.
    Watts is voltage x amperage.
    So 120 V x 10 amps = 1,200 Watts
    and 240 V x 5 amps = 1,200 Watts

    I don't see any difference.


    Current capacity in wires varies with temperature. Running more current heats the wire- that heat is wasted efficiency. 5 amps in a wire runs cooler than 10 amps in a wire.

  9. #24
    Join Date
    Dec 2006
    Location
    Toronto Ontario
    Posts
    11,248
    Quote Originally Posted by Anthony Whitesell View Post
    Runs cooler because it uses less amperage.

    Electric cost won't change. (120V @ 15A = 1.8kW, 240V @ 7.5A = 1.8kW)

    Gauge wire required is smaller, thus less expensive for the same motor. Or for the same expense (installation of 12g wire) you can run high HP motor. On a 120V 20A breaker with 12g wire the highest HP motor is 2, whereas a 3HP motor can be run on the same wire using 240V.

    Spin up time will be less, but not by an amount that a human would care about.
    Motor temperature will not change whether it’s running on 120 or 240 volt

    In 120 volt mode you have 2 windings with 7.5 Amperes current, in 240 volt mode you have 2 windings with 7.5 amperes current, exactly the same in both cases.

    Regards, Rod

  10. #25
    Join Date
    Mar 2006
    Location
    SoCal
    Posts
    22,493
    Blog Entries
    1
    Quote Originally Posted by Anthony Whitesell View Post
    Runs cooler because it uses less amperage.

    Electric cost won't change. (120V @ 15A = 1.8kW, 240V @ 7.5A = 1.8kW)

    Gauge wire required is smaller, thus less expensive for the same motor. Or for the same expense (installation of 12g wire) you can run high HP motor. On a 120V 20A breaker with 12g wire the highest HP motor is 2, whereas a 3HP motor can be run on the same wire using 240V.

    Spin up time will be less, but not by an amount that a human would care about.
    Glad Anthony chimed in with this. There is a lot of misunderstanding about this. Watts are watts and that's what you pay for.
    "A hen is only an egg's way of making another egg".


    – Samuel Butler

  11. #26
    You have sufficiently large gauge wire for the length of the circuit and the load? 120V is fine.
    You want to save some money by using smaller-gauge? Use 240V.
    The motor doesn't care either way.

    Cost of the wire is the only concern. All this about efficiency/losses/"running hot"/cost/etc is either plainly wrong or so trivial as to be meaningless.
    Last edited by Dan Friedrichs; 04-01-2023 at 7:59 PM.

  12. #27
    Join Date
    Nov 2022
    Location
    Northern Colorado
    Posts
    1,066
    Quote Originally Posted by Dan Friedrichs View Post
    You have sufficiently large gauge wire for the length of the circuit and the load? No benefit to 120V.
    You want to save some money by using smaller-gauge? Use 240V.
    The motor doesn't care either way.

    Cost of the wire is the only concern. All this about efficiency/losses/"running hot"/cost/etc is either plainly wrong or so trivial as to be meaningless.
    This is pretty much correct. The efficiency is in the cost factor of the wiring to carry that power. I wouldn’t call that meaningless, but you’re pretty much on point otherwise.

  13. #28
    Quote Originally Posted by Michael Burnside View Post
    This is pretty much correct. The efficiency is in the cost factor of the wiring to carry that power. I wouldn’t call that meaningless, but you’re pretty much on point otherwise.
    Oh, for sure - a 240V 15A circuit could be run on 14AWG wire that is less than half the cost of a power-equivalent 120V 30A circuit on 10AWG wire.

    I meant that the concerns about losses are trivial. E.g. if you had a 16A 120V circuit 100' long, you'd lose about 3% more power versus 8A 240V on the same-sized wire, and even that is only when the tool is running at full-load.

  14. #29
    Join Date
    Feb 2003
    Location
    Lafayette, IN
    Posts
    4,563
    Something to consider when wiring: You can run 12/3 w/ground to receptacle boxes, then alternate 120V receptacles on the black and red hot legs. Then, if you need 240V, you have the wiring in place to make a 240V/20A receptacle. Or, you could even run 10/3 and have the possibility of future 240V/30A, but a little more difficulty in the wiring, 10 gauge wiring being a little stiffer to work. I always pigtail receptacles—I attach a 6” lead of solid 12-gauge wire to the receptacle screws, then wire nut those leads to the circuit wiring in the box. Those leads need to match the amp rating of the breaker, though.
    Jason

    "Don't get stuck on stupid." --Lt. Gen. Russel Honore


  15. #30
    Join Date
    Feb 2003
    Location
    Griswold Connecticut
    Posts
    6,927
    Quote Originally Posted by Keegan Shields View Post
    The greatest benefit is that you can now buy used 220v machines and step up from the consumer level equipment. I’ve experienced far less competition for 220v machines than 110v on CL.
    Yep, this is the one and only advantage.
    A person will evolve to a point where they need/want bigger, more powerful, machines. Especially the dust collectors.
    If you're going to run 240 circuits, do the wiring once and install 10awg. Yes, I know 12awg will work for most machines in a garage shop, but 10awg has you prepared when you do want to finally step up.
    "The first thing you need to know, will likely be the last thing you learn." (Unknown)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •