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  1. Replies
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    2,912

    The ball and roller are hardened, and rated for...

    The ball and roller are hardened, and rated for the usage. And the elastic deformation of the surfaces makes the ball and roller actually have larger contact patches than a "line".

    I don't like...
  2. Replies
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    935

    Check the manual. A quick look at specs showed...

    Check the manual. A quick look at specs showed that max torque seems to be at 2k rpm.

    That's not unusual, depending on how they have the motor and drives set up. Overspeeding the motor when...
  3. Replies
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    2,697

    This is a huge example of "overthinking". You...

    This is a huge example of "overthinking".

    You have 170watts or so of output, which the amplifier can deliver. Get some speakers which you like the sound of, and which can take your 170 watts....
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    2,912

    Actually they do not.... The journal is...

    Actually they do not....

    The journal is smaller than the bore, to allow oil room, so the contact is actually only over a theoretical line, but actually a larger area based on the hardness and...
  5. Replies
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    684

    The control contacts involved may or may not be...

    The control contacts involved may or may not be on the "hot" part of the VFD. They are set and forget jumpers, so they might be without a problem, but probably they are on the I/O controller...
  6. Replies
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    2,912

    One of the lathes here weighs maybe 500 lb, but...

    One of the lathes here weighs maybe 500 lb, but the nose ball bearing has max rating of 8000 lb, in the bearing data. Somehow I doubt there would be an issue there. I'd still not do it, just...
  7. There should be NO concern about the neutral...

    There should be NO concern about the neutral coming off the RPC..... because there is generally no NEED for a neutral, and that wire is simply not "pulled" (installed) to the connection points.
    ...
  8. Replies
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    2,697

    There is a lot to what EPAIII said. Powered...

    There is a lot to what EPAIII said.

    Powered speakers CAN BE very very good. but shop sound does not need that.

    I also would have that receiver at home..... totally wasted on a shop. ...
  9. What do new engineers need to KNOW? That's easy,...

    What do new engineers need to KNOW? That's easy, they need to know everything that they don't know now.

    What do they need to HAVE? An actual interest in whatever branch of engineering they went...
  10. You should not lose anything. All the windings...

    You should not lose anything. All the windings will be contributing.

    The only reason for the star point to neutral in the first place is to get the motor started as 2-phase without more...
  11. That motor is absolutely wired correctly for the...

    That motor is absolutely wired correctly for the use. The 220/380 combination is delta at 220, and star (wye) at 380. Double sets, so two winding sets, and double star for the 380/400.

    The...
  12. Delta isn't gonna help much, so if that is what...

    Delta isn't gonna help much, so if that is what you have available, then just pretending you have single phase (no neutral), and going the normal RPC route, (just at 415V) may be what you have to do.
  13. Wye motors in other places are often connectable...

    Wye motors in other places are often connectable wye or delta, they are 6 wire motors. The wye point is therefore available on such motors. Not all are like that, no more than all US motors are...
  14. My understanding of the zig-zag transformer is...

    My understanding of the zig-zag transformer is that it requires 3 transformers / 6 windings, not two as seems to be implied. And I am not sure about the "solidity" of the power passed through. The...
  15. Because you have 2 legs and neutral, you have a...

    Because you have 2 legs and neutral, you have a genuine "two phase" system, which should start and run a 3 phase motor just fine on it's own, but at somewhat reduced power.

    You really do not...
  16. Replies
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    8,915

    Motors with capacitors are used in many places as...

    Motors with capacitors are used in many places as a very robust generator. I've made them. If the (in)correct capacitor is used, the voltage can be very high. Motor needs to be "flashed" to...
  17. Yes, that should be fine, if you include the...

    Yes, that should be fine, if you include the neutral. You will have a rotating, if somewhat "lumpy", phase sequence. It should start the motor.

    But starting a large motor on the typically...
  18. If the OP has 2 lines which are 400V between...

    If the OP has 2 lines which are 400V between them, he is all set up. A 400V motor can run on that single "phase", and generate the third wire and the two added phases that go with it.

    It will...
  19. If there are several drives , and only one shows...

    If there are several drives , and only one shows a fault, there is always the chance that for some reason that one drive is over-sensitive. Possibly variation of component values inside, maybe an...
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    Don't forget that in US factories, the complete...

    Don't forget that in US factories, the complete time for an operation on a part was referred to as the "floor to floor time".

    Look at pics of old US factories to find out why.
  21. There are two ways a disease can succeed. One...

    There are two ways a disease can succeed. One is by becoming less likely to kill the host, obviously. The other is by becoming very contagious, so that even though it kills the host very...
  22. If it is indeed an overvoltage situation, it may...

    If it is indeed an overvoltage situation, it may have more to do with Sunday and less to do with the drive.

    Because businesses are closed Sunday, the mains voltage supplied may be higher due to...
  23. Replies
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    EE also, designer of VFDs at the last employer. ...

    EE also, designer of VFDs at the last employer.

    1) Most VFDs are N.O.T. designed for component level repair.

    2) dead IGBTs almost always means dead driver chips. Count on replacing them...
  24. Replies
    186
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    8,915

    The 3% is 7 volts at 240VAC.

    The 3% is 7 volts at 240VAC.
  25. Replies
    186
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    8,915

    If you get the balance to under 3%, that's as...

    If you get the balance to under 3%, that's as good as the powerco will guarantee.
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