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Are these Digital Phase Shifters any good.

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  • #16
    Originally posted by lakeside53 View Post
    In theory it will do better then a "normal" static converter, but hard to know how much across varying conditions.

    Nomenclature.. careful... "safely develop power" is better than "make power". They will "make" whatever you load them to until you collapse the field, stall or overhead and burn up. I don't know where the 2/3 comes from (they will develop 1.x if you load them)... but safely it's closer to 50% of that at three phase in most cases. If you follow the Nema derating recommendation for unbalanced currents, it can be as low as 30%. Fuse/limit to no more than the name plate FLA is reasonably safe.
    Is there any thing to gain by upsizing one of these?

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    • #17
      Originally posted by Tundra Twin Track View Post

      Is there any thing to gain by upsizing one of these?
      Not really, they just compensate by adjusting the capacitor, if they have the range.
      CNC machines only go through the motions

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      • #18
        Originally posted by lakeside53 View Post

        If you plug reverse ("instant" direction change) your spindle, RPC, PP or three phase will work; VFD will not. It's not hard to run multiple tools off a single VFD - many allow multiple motor profiles. If you want to run modbus or whatever supported from a laptop, you can remap your vfd completely in seconds when changing machines. I prefer 1 dedicated to each, but I did put an external 3 phase plug output (motor plug) on the back of a couple for test purposes.
        I don't understand, why would you reverse legs to change direction rather than use the VFD, which will slow and reverse safely? I know you can plug in multiple motors, but I recall if you don't power down the VFD, you can damage it.
        Location: Jersey City NJ USA

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        • #19
          For a 100 YEARS before VFDs. plug reversal has been used to immediately change direction. Designed right it's damn good. Use carelessly, you and break a lot of stuff. It was/is a std technique on mills for power tapping. I use it on my lathe now and then for those "oh crap moments".

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          • #20
            I would think for that price you could buy a small VFD.

            JL.............

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            • #21
              Saw something at my new job today. A single large VFD with contactors on the output to run one large spindle alone, one small spindle alone or 3 or 4 small spindles together. We’ve got another machine coming in with 2 VFDs and 16 spindles!

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