Phase rotation test of 3 phase 460 VAC motor.

Discussion in 'General Electronics Chat' started by shteii01, Dec 11, 2016.

  1. shteii01

    Thread Starter AAC Fanatic!

    Feb 19, 2010
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    I am looking at one of the "volt sticks" on amazon and ebay. UNI-T UT15 and UT18 in particular. I started reading the manual and I see that this test is performed at range of 57 to 400 volts.

    My goal is to have all the 3 phase 460/480 VAC motors going in direction I need. Often time I have some motors going in apposite direction so I have to go back and rewire them. I am trying to avoid doing the rewiring. I want to do it one time, get it correct the first time and move on to the next assignment.

    So. Is the 400 volt appropriate for 3 phase 460/480 VAC motor?

    P.S. Please see Phase Rotation Test in Section 17 in attached excerpt from the manual.
    uni-t ut18.jpg
     
  2. Reloadron

    Distinguished Member

    Jan 15, 2015
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    When doing phase measurements you use it measuring for example phase to phase as in L1 to L2 and L2 to L3 and L3 to L1 and it will tell you if for example L1 leads L2 and L2 leads L3 and if L3 leads L1. While they are inexpensive I much prefered using one of these from McMaster Carr or any industrial supply house. I still have my ancient General Electric GE Phase-sequence Indicator Cat. No. 5467032g5 W Case 107 to 625 Volts which served me well for decades. Really, if you want a phase rotation indicator I would just buy a 3 wire phase rotation indicator rather than using a two wire method and going phase to phase to phase.

    If that is your goal I would get the tool made for what you want to do.

    Ron
     
  3. shteii01

    Thread Starter AAC Fanatic!

    Feb 19, 2010
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    Ok. I will drop the volt stick then. I did start this with looking at the 3 wire phase rotation indicators, but the Fluke one is just too bloody expansive, and I did not want to clutter the tool box with a bunch of different boxes. UNI-T has UT261 which is what you are talking about, that just one example, I will probably end up with something else since I am not stuck on any brand.
     
  4. Reloadron

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    Your call, when I was buying stuff like this my company had deep pockets so cost was never a real big deal. For phase rotation I just prefer the 3 wire devices. We had some pretty high end pumps and while they would run backwards they would not do it well for long leading to high cost if we screwed up the 480 VAC mains phase rotation. :)

    Ron
     
  5. shteii01

    Thread Starter AAC Fanatic!

    Feb 19, 2010
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    I very much appreciate the guidance you gave me. This is exactly the sort of thing I look for when I ask for advice on equipment. Unlike your situation, I deal with "regular" none specialized motors. All they have to do is run in whatever direction the print shows.

    I looked up the GE device you mentioned, ebay got 3 or 4 of them, 180 the cheapest one, and that is for used!

    The McMaster devices are over 100 each and they look like the 30-50 dollar devices on ebay, and we both know that McMaster, Klein, Snap-On, Greenlee, Matco, etc. ARE NOT test equipment or even electronic companies. So. WTF do they know about designing and making electrical test equipment? Nothing. All their test gear is rebranded stuff. I will not pay top dollar for rebrands, I don't care whose name is printed on the rebranded item.

    I see myself picking something in 30-40 dollar range. Thank you for steering me toward the 3 wire devices, I need that sort of professional advice.
     
  6. Reloadron

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    Jan 15, 2015
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    My pleasure and have a good one. :)

    Oh yeah, that old GE unit I have is more like a sentimental classic. Actually as to the internal guts? A few neon lamps, resistors and a capacitor is really all there is to one of them. Wow, can't believe tha asking prices on Ebay.

    Ron
     
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