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  • Horsepower question

    Hi all! I've been reading the forum for some time, but this is my first post.
    I bought a Delta 14 inch bandsaw rated at 1.5hp, but while I was assembling it I noticed it said on the motor it is 2hp. Not having much knowledge about electrical stuff, I was wondering if this is the actual hp of the motor or if the saw is still rated at 1.5hp?

  • #2

    Re: Horsepower question

    Re: Horsepower question

    Originally posted by heindj View Post
    Hi all! I've been reading the forum for some time, but this is my first post.
    I bought a Delta 14 inch bandsaw rated at 1.5hp, but while I was assembling it I noticed it said on the motor it is 2hp. Not having much knowledge about electrical stuff, I was wondering if this is the actual hp of the motor or if the saw is still rated at 1.5hp?

    Could mean just about anything...

    Power delivered to the blade?

    Maybe they are telling the truth about the motor as opposed to a manufacturers fantasy?

    http://www.howstuffworks.com/horsepower.htm

    http://en.wikipedia.org/wiki/Horsepower
    ---
    Will

    “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” —- Mark Twain

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    • #3

      Re: Horsepower question

      Re: Horsepower question

      Originally posted by heindj View Post
      Hi all! I've been reading the forum for some time, but this is my first post.
      I bought a Delta 14 inch bandsaw rated at 1.5hp, but while I was assembling it I noticed it said on the motor it is 2hp. Not having much knowledge about electrical stuff, I was wondering if this is the actual hp of the motor or if the saw is still rated at 1.5hp?
      Out of curiosity, which model is it?
      If the plate on the motor said 2 hp, then I presume that's what it is. What does it say for AMPS and voltage on the motor plate? For 2 hp I expect it is 220V only and @12 amps rather than 110/220 dual voltage often found on motors rated up to 1.75 hp.

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      • #4

        Re: Horsepower question

        Re: Horsepower question

        If you take the voltage and multiply by the current and then multiply by 0.7 you will get the approximate output power of a single phase motor in watts. Divide this by 746 to get HP.

        ie: 120*18*0.7/746=2.03HP
        Claude


        “Small minds discuss people, average minds discuss events, great minds discuss ideas.”
        Admiral Hyman Rickover

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        • #5

          Re: Horsepower question

          Re: Horsepower question

          horsepower ratings on tools generally is a totally bogus way to indicate the performance of the tool, a shop vac from ridgid for example says 6.5 peak horse power. thats a ridiculous rating and imposible with a normal 120 volt circuit

          automotive horsepower ratings are equally bogus, our minivan is supposed to be a little over 200 hp, sure at 6000rpm!! just before the motor turns into a molten lump of castiron and aluminum!!

          the best way to evaluate the power of a tool is to try it, if its adequete, thats all that matters
          my shop is a beaver lodge
          steve, sarnia, ont

          sigpic

          1940's Beaver Jointer

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          • #6

            Re: Horsepower question

            Re: Horsepower question

            Originally posted by stevem View Post
            horsepower ratings on tools generally is a totally bogus way to indicate the performance of the tool, a shop vac from ridgid for example says 6.5 peak horse power. thats a ridiculous rating and imposible with a normal 120 volt circuit
            This is true of universal motors but induction motors are mush more realistic in their HP ratings. The efficiency is the real unknown that is seldom revealed and that is why I picked a mid range value of 70% and said the result would be approximate.

            I suspect Delta had a supply problem so they just substituted an "equivalent or better" motor to get product out the door.
            Last edited by Claude in Kitchener; 06-23-2009, 10:31 AM.
            Claude


            “Small minds discuss people, average minds discuss events, great minds discuss ideas.”
            Admiral Hyman Rickover

            Comment


            • #7

              Re: Horsepower question

              Re: Horsepower question

              Just count yourself lucky to have received more than you paid. Its usually not the case.

              I just picked up a Jointer with a 3HP motor. Here is the spec. 230/115 volt Single Phase ... I will put it to 230, as it is currently configured at 115v ... don't ask. Its a beast of a motor ...

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              • #8

                Re: Horsepower question

                Re: Horsepower question

                I have the exact same motor on my Delta Contractor saw. The 2hp is for 220V only. The Delta motors have extra windings for the 220V aspect, providing the extra half horse. I have a friend who used to work in a motor shop and he said this setup (extra windings) is not all that unusual.

                Tim

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                • #9

                  Re: Horsepower question

                  Re: Horsepower question

                  It's the 475X that I bought. It's wired for 110/120V as far as I know. I'll have to check the amps on the motor casing. Is it possible that it is a 2hp motor wired in a way that it runs off 110V? As I said, I don't know much about electricity.

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                  • #10

                    Re: Horsepower question

                    Re: Horsepower question

                    Originally posted by heindj View Post
                    It's the 475X that I bought. It's wired for 110/120V as far as I know. I'll have to check the amps on the motor casing. Is it possible that it is a 2hp motor wired in a way that it runs off 110V? As I said, I don't know much about electricity.
                    My TS is 2HP and comes from the factory wired to run on 110v. Its rated 18A @ 110v and 9A @ 220v. I run it at 220v.
                    Claude


                    “Small minds discuss people, average minds discuss events, great minds discuss ideas.”
                    Admiral Hyman Rickover

                    Comment


                    • #11

                      Re: Horsepower question

                      Re: Horsepower question

                      Interesting. On the wheelcover it says 12.8 amps and on the motor it says 15 amps @ 115V. Quess I did get a 2hp motor wired for 110 in a 1.5hp saw afterall!

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                      • #12

                        Re: Horsepower question

                        Is it Possible - Yes

                        Originally posted by heindj View Post
                        Is it possible that it is a 2hp motor wired in a way that it runs off 110V?
                        In short - Yes

                        The basic, simplified version is that horsepower is a measure of work done per unit of time ( seconds normally). a specified amount of effort done over a period of time. In electrical terms this is normally measured in watts per second or kilowatts per hour ( KWH as seen on the electrical metre).

                        Watts are calculated by multiplying the voltage by the amperage ( I don't want to confuse things by explaining DC and AC ). Note that this is what is going into the motor. All motors loose a bit of energy while converting it from electrical to mechanical, that is where the .7 ( I.E. 70% efficiency) came from ( lets not get into power factors --- please )

                        So 110V @ 30A gives the same wattage as 220V @ 15A and hence gives the same horsepower, assuming all other things are equal.

                        220V is normally preferred since the size of the wire in a power circuit determines its maximum safe amperage while the insulation determines the safe voltage. Regular household wiring can carry 15A but is rated for over 600V. Therefore it is easier and cheaper to go 220@15A than to go 110V@30A. The windings inside the motor also come into the calculation as well.

                        One electrical horsepower is 746W so a 110V@15A circuit can supply about 2.2 HP. Assuming 70% efficiency you get 1.5HP on the output side of the motor. So 1.5 to 2 HP are reasonable claims for a motor on a regular home circuit, anything larger and they are selling snake oil.

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                        • #13

                          Re: Horsepower question

                          Re: Horsepower question

                          Thank you very much for the detailed reply. I do have 220V in my shop as well, but is it worth it to change over to 220 for the bandsaw just for an extra half a horse. I don't do much resawing.

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                          • #14

                            Re: Horsepower question

                            Re: Horsepower question

                            Originally posted by heindj View Post
                            Thank you very much for the detailed reply. I do have 220V in my shop as well, but is it worth it to change over to 220 for the bandsaw just for an extra half a horse. I don't do much resawing.
                            You get full power at either voltage. It is slightly more efficient to run it at 220v but it's not a big deal. What matters more is how much power you have in your shop and the number of circuits relative to the number of machines to be used at one time and the power they use. For a one man shop, if you can run any one machine and your dust collector without blowing a breaker that is usually sufficient.
                            Claude


                            “Small minds discuss people, average minds discuss events, great minds discuss ideas.”
                            Admiral Hyman Rickover

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                            • #15

                              Re: Horsepower question

                              Re: Horsepower question

                              After I read the post about getting an extra 0.5 HP, I wondered if it was a Delta saw. Checking the first post indicates that is indeed the case.

                              I have read elsewhere about Delta having a dual-voltage motor that is not the usual "coils in series for 240V and coils in parallel for 120V" configuration. IIRC, it actually has an extra coil that comes into the circuit in the 240V configuration which gives the motor extra power at 240V.

                              billh

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