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Onan 60 kw 3 phase voltage fluctuates

mattyt1984 · 2022-09-08 16:12

I can't get A steady voltage it constantly bounces around from 200- 300 volts across all legs. I changed voltage regulator but does the same thing.

Replies20
  1. #1mattyt19842022-09-08 16:36

    I'm guessing year is around 1980ish attached is pics.

  2. #2Birken Vogt2022-09-08 21:19

    I would see what kind of excitation voltage the regulator is delivering. Then feed it the same voltage from a set of batteries and see what it does then. I am thinking loose diode connection or something of that nature, maybe.

  3. #3mattyt19842022-09-08 21:33

    Could it be the voltage regulator part number onan 305-524? The voltage regulator I changed was the one that actually adjust the voltage higher or lower.

  4. #4Birken Vogt2022-09-08 22:32

    I don't understand what you are saying. There is only one voltage regulator. What is the model and serial?

  5. #5mattyt19842022-09-08 22:39

    I can't find a model or serial. On the outside of panel there is an adjustment knob for voltage adjustment. Also there is a voltage regulator that has part number 305-524 that is inside control panel

  6. #6Birken Vogt2022-09-08 22:50

    Try posting this at Smokstak.com, they might know this old regulator better than I do. And also what model you have.

  7. #7MarshallPowerGen2022-09-09 11:27

    Is the HZ steady or is it fluctuating with the voltage (or at all)? Messed with any of the pots on the VR board? I agree with Birken on taking this to Smokstak, they are the spot for old Onan equipment. https://www.smokstak.com/forum/forums/onan-generators.1/

  8. #8mattyt19842022-09-10 16:17

    The hertz is a steady 60 hz. I adjusted the dampening on the cicrcuit board it worked but then went back to bouncing all over. I have video that I could email if needed Thank you I'm waiting to be registered in smokstak

  9. #9Birken Vogt2022-09-10 18:53

    While you wait at smokstak, upload the video to youtube, it's easy and then you can just post a link and everyone can see it easily. Emailing videos is much too huge of a file to be passing around.

  10. #10mattyt19842022-09-10 20:11
  11. #11Camshawn2022-09-10 21:22

    Are you confirming the voltage readings with a volt meter on the mains? Those meters always bounce but usually settle down after a few seconds. Cam

  12. #12mattyt19842022-09-10 21:27

    Yes confirmed with meter also it shuts down on fault after a few minutes

  13. #13Camshawn2022-09-10 21:59

    You said you changed the AVR. Did you change the voltage adjustment pot on the door? Also, what shutdown are you getting? I have seen pots go bad causing erratic readings due to vibration on generators and other equipment. If yes, have you gone through all the connections looking for a loose or partially broken wire including the field connections and the sensing wires?

  14. #14mattyt19842022-09-10 22:21

    How do I determine what is shutting it down? I've tested all the connections and appear to be tight

  15. #15mattyt19842022-09-10 22:42

    I've adjusted the pot with a screwdriver and the damper. It woreked for. A day they it's bouncing around again.

  16. #16Camshawn2022-09-10 22:46

    The AVR is the circuit board in your video with the little pots. I have replaced several AVR’s because the little pots develop dead spots in them. I would look for a schematic to help identify test points for the cause of the shut down. It has been a while since I looked at one of these generators and my memory is a little fuzzy. Cam

  17. #17mattyt19842024-04-04 21:48

    I finally got a new board and that was the issue. Next question how do you rewire for 480 see attached pic of plate

  18. #18MarshallPowerGen2024-04-05 22:45

    240/480 or 277/480? Diagram is there, you just need to connect your leads as shown. Pull the lid and see how they're currently set up and compare to the diagram, then change to the output you want.

  19. #19mattyt19842024-04-06 02:35

    How can you be wired 240/480 at same time?

  20. #20MarshallPowerGen2024-04-06 12:09

    Delta, line to neutral. Just look at the diagram you posted.