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  • 220 vs 110?

    Is there any advantage to running single phase motors on 220 instead of 110? Realizing the current is halved I've heard you can run smaller gage wire, but I dunno if that's such a big deal. I tend to overbuild every thing I do anyway!

    Unless there's some kind of disadvantage, I think I'll be switching two 3/4 motors over to 220 just to get them off the 30 amp circuit that my whole garage is currently on. 50 amp breaker on the 220.

    SP

  • #2
    Yes.
    You will waste less power in the feed lines and it will cost a tad less to run your motors

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    • #3
      If you have the option, and it sounds like you do, any machine/motor will be "better" at 220 v 110. A "real" electrician or electrical engineer will be able to give you the technical reasons why. I don't see any disadvantage doing the "change" (and you can always rewire back to 110v if you are not happy with the results).
      Today I will gladly share my experience and advice, for there no sweeter words than "I told you so."

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      • #4
        Mad Science pretty well nailed it as far as economics. If you notice some lights in the house dimming very briefly when a motor starts, you may find that the phenomonon goes away when you change over to 230V. Starts may also be a *little* quicker as voltage and current drops in the wiring will have less influence on the motor.
        Weston Bye - Author, The Mechatronist column, Digital Machinist magazine
        ~Practitioner of the Electromechanical Arts~

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        • #5
          Thanx guys.

          The feeble brain hasn't stopped spinning yet tho. Had another thought. I've already decided to VFD the benchtop lathe I'm building a home for, and now I'm thinking I oughta just run the whole bench off the VFD. Sensorless Vector even!

          A good internet buddy of mine is some kinda Industrial Controls Engineer and he explained the SV technology to me in words even I understood.

          Used to be if you wanted a motor to run at a steady rpm despite the load, you had to put a sensor on the actual shaft for the feedback to make a correction. What the SV does is monitor harmonics on the power line to tell when the motor's slowing down. No sensors. Hence the word "sensorless".

          He then went on to explain what the word "vector" meant, but that's already escaped thru the haze!

          Anyway, the 3/4 motors are on a bench grinder and a disc/sander combo and I'm always slowing them things down. It's all about instant gratification and I want it ground down now! I lean on 'em hard when necessary.


          A VFD with SV technology might make for some real strong grinders. Then again, it might fry 'em to a crisp.

          Any thoughts?

          SP

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          • #6
            If the motors of interest are single phase, I don't believe you can run them with a VFD to get variable speed. Charles

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            • #7
              Originally posted by Mad Scientist
              Yes.
              You will waste less power in the feed lines and it will cost a tad less to run your motors
              You almost certainly will not ever notice the difference in cost. It only matters significantly at far higher voltages and longer distances than you will ever need to worry about.

              You MAY notice a nippier startup on motors, possibly a little edge on power. But most likely extra power will never be noticed, since you rarely demand full power anyway.

              But your light will dim less, if only by removing the neutral current.

              No, single-phase are not usable with a VFD, except in the most theoretical and impractical way.

              220 is nice, but don't spend much to do it unless you convert to 3phase and VFD, in which case it becomes very nice.
              3751 6193 2700 3517

              Keep eye on ball.
              Hashim Khan

              If you look closely at a digital signal, you find out it is really analog......

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              • #8
                220V vs. 110V

                JTiers is right....with 220 VAC your motor current will be approx. halved vs 110 VAC so feeder conductor size and over current protection (circuit breaker(s) and motor starter) will be smaller/ cheaper, but not by half....
                Single phase isn't practical for use with a VFD....either spend the $ for a VFD & appropriate HP 3 phase motor or go to a DC set-up aka a treadmill motor, if you are into DIY.
                My thoughts, anyhow.

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                • #9
                  I concur with JTiers and '4200. No savings in running costs with 230 Volts compared to 115. 230 is nice to have in the shop though. It makes hooking up larger equipment that followed you home that much easier. Also the VFD thing is made simpler. No hooking single phase motors to a VFD. Strictly a three phase output.

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                  • #10
                    Railfan got me! Of course the grinder motors are single phase and the VFD's all about getting 3 phase for the lathe. It's apples and oranges. That ain't gonna work.

                    Sometimes I think too much .....

                    SP

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                    • #11
                      SP

                      As has been stated, the biggest advantage to 220 vs 110 power is the lower currents. My compressor has an instantaneous starting current of 15+amps and a running current on 110v of 13.8 amps. If any other loads are running, the weather was cold, or the line voltage was down (high useage on a rural service) the compressor tripped the 15 amp breaker. Converting to 220 the currents are roughly 8 and 6.9 amps. I can run both my compressor and plasma cutter on the same 15 amp 220 circuit.
                      FWIW
                      Cam

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                      • #12
                        I don't think the currents seen in the home shop would really be much savings going 220 vs 110.

                        Think of voltage as "electricity pressure". In a water pipe, more pressure means you can deliver more water with a smaller pipe. More pressure means the water moves faster down the pipe. Amps is the "speed" of the electricity moving down the wire. (actually the electron drift velocity. More voltage means the electron drift velocity in the wire is higher for a given resistance - that's more amps) Watts would be analogous to "gallons per minute" and kilowatt-hours analogous to "gallons delivered".

                        The reason power companies send power over high voltage lines is to save copper (or whatever metal the wire is made of). "Pressurize" the electricity and you need a smaller pipe to deliver the same amount.

                        Three phase is just a better way to run motors. It means you can have easy speed control, and you don't need a bunch of trickery with capacitors to get the motor started.

                        -Mark
                        The curse of having precise measuring tools is being able to actually see how imperfect everything is.

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                        • #13
                          The lower current means less hysteresis losses in both the supply lines and the motor windings. While that may not translate to much in terms of cost savings, it could mean longer motor life due to less heating. It does also mean faster motor startups and less aptitude to stall. As the motor approaches stall or "locked rotor" current, the losses in the wire feeding the motor go up meaning less power is delivered to the motor itself.

                          P=I^2*R Sooo...if current doubles, the losses in the wire go up by a factor of 4.

                          I run just about everything that is over 1HP on 220v. My saw starts quicker etc.

                          I disagree that circuit protection will be cheaper. My experience is that you will likely be using a 20amp breaker to protect wiring for a service for say a 2HP motor no matter which voltage you would run it at....and the 220v breaker will cost more than the 110v breaker. Perhaps ****s42000 was referring to motor protection and not circuit protection, however, where thermal overload protectors for one "phase" are cheaper than for 2 or three "phases".
                          Paul Carpenter
                          Mapleton, IL

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