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Thread: rtac/rtaa

  1. #1
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    rtac/rtaa

    can you test a screw with a megger? another tech in my company claimes he checked a compressor that was throwing the breaker with a megger against a compressor that was working ok and got the same readings.???????

  2. #2
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    You can check any motor windings with a megger.

    What makes you think he's lying?
    UA LU189

    10mm, because it's better than .45acp

  3. #3
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    dont meg in a vac., and dont over voltage the meg tool with the applied voltage .,

    example: 208 motor
    meg with 208 not 600 volt
    no signature blast'em man blast'em
    !!!KILL THE TERRORIST!!!

  4. #4
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    Quote Originally Posted by mlkwal1 View Post
    and dont over voltage the meg tool with the applied voltage .,

    example: 208 motor
    meg with 208 not 600 volt
    What??????

    Can you please enlighten us on this????

  5. #5
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    The same rules apply as to any other motor. But with an RTAC you will probably see lower readings than you would expect. I suspect that has more to do with the POE oil than it does with the motor.

  6. #6
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    Yes you can and what were the megger readings???? Was the one tripping the breaker grounded, or pulling LRA?


    Sent from my iPhone using Tapatalk

  7. #7
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    You can get a bad meg reading on a good rtaa screw compressor. If the compressor has the old style terminals and is rusty under the motor terminals insulators. I have had them go as low a .5 megaohms.

  8. #8
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    Quote Originally Posted by R123 View Post
    What??????

    Can you please enlighten us on this????
    Well I can try, haha
    I know for a fact that not supposed to meg n a vac
    As far as my example : we'll that may be wrong example.,
    Guess what I was trying to say was if you compressor motor volt rating is 600 volt, not supposed to meg at a higher voltage., am I correct in typing this??
    no signature blast'em man blast'em
    !!!KILL THE TERRORIST!!!

  9. #9
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    It`s not the voltage that kills a motor. It`s always the current. I haven`t seen an compressor motor killed by megging him. But most compressor manufacturers recommend not to megger with a system in deep vacuum.
    "Quality exists, when the price is long forgotten."

    Henry Royce

  10. #10
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    Quote Originally Posted by mlkwal1 View Post
    Well I can try, haha
    I know for a fact that not supposed to meg n a vac
    As far as my example : we'll that may be wrong example.,
    Guess what I was trying to say was if you compressor motor volt rating is 600 volt, not supposed to meg at a higher voltage., am I correct in typing this??
    You are correct that you are not supposed to meg in a DEEP vacuum but I've never heard about not to meg at a higher voltage. As a matter of fact, my megged doesn't go below 500 volts and I meg 230 volt motors all the time.

  11. #11
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    Mlk, after researching this, you are right about not to meg at a much higher voltage than the voltage rating of the motor.

  12. #12
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    you should set the voltage at twice the rated voltage,
    I almost exclusively work on 480 stuff
    i always meg at 1000 volts.




    Quote Originally Posted by R123 View Post
    Mlk, after researching this, you are right about not to meg at a much higher voltage than the voltage rating of the motor.
    I WILL SELL WORK,GENERATE BUSINESS, GO GET NEW CUSTOMERS!
    YOU SHUT THE HELL UP AND QUIT RUNNING YOUR MOUTH!

  13. #13
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    Quote Originally Posted by supertek65 View Post
    you should set the voltage at twice the rated voltage,
    I almost exclusively work on 480 stuff
    i always meg at 1000 volts.
    i meg everything at 1000 VDC...even 115 VAC motors...no problems. i have also megged motors in 500 micron vacuums without issue...my megger tops out at 0.002 ADC...not gonna hurt anything.

    applying line voltage to a motor in a deep vacuum...now that's a youtube video I want to see!
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