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DPGBG's avatar
DPGBG
Explorer
Aug 04, 2015

HF Predator mod to parallel

Hello all. First time posting and impressed with the help on this forum.

I'm trying to re-wire a HF generator to parallel. I have tried many things I found on this site as well as others and I just cant seem to get it to work. I have the wiring diagram but not sure how to get it on this forum. If anyone can help I can e-mail it to you.

What I have tried was to switch the wires as explained in the 3000W Chinese Gensets Info. topic on this site. I do that and I get 20 volts across the two outputs. I also read that if you get 0 to 50ish volts to switch a set of leads. I didn't try this and I'm not 100% clear on which two leads to switch??

To try and explain without the diagram, I have 4 wires coming out of gen head. Coil 1 has Red and White. Coil 2 has white and black. Red and black are power and whites are neutrals. Coil 2 is the only coil that the AVR monitors.

So at the terminal block, I take coil 1 red and coil 2 white and put them together, and coil 2 black and coil 1 white and put them together. When metering across the two I get 20 volts.

I have been testing at the terminal block figuring if I can get it to 120 volts there then I will worry about the rest of the plugs and things down stream.

Any help would be greatly appreciated.
Thanks all..
  • DPGBG's avatar
    DPGBG
    Explorer
    Aug 06, 2015
    DrewE the measurements are at the terminal block. I removed all the other wires to the plugs. All I did was swap around stator wires at the terminal block.

    The two whites are not connected when trying the parallel. The two whites are connected up towards the 240 plug and I have those wires disconnected from the terminal block when testing.

    There are two sets of wires coming out of internal windings. They are separately sheathed. One set is red and white and they check out with continuity the other is black and white and they check out with continuity.

    I think I am wiring it correctly for parallel. My thought is it might be the AVR keeping this from working. I don't know if the AVR needs to see the neutral. ???

    other thought is maybe I cant stack the wires at the terminal. Maybe I have to use separate lugs and run a short wire and connect them together farther down the line. If that makes sense.

    Not sure. I was hoping someone on here has had this issue before and could give some advice.
  • DrewE's avatar
    DrewE
    Explorer II
    Aug 05, 2015
    It sounds to me like you have the correct wiring in mind, if the diagram is to be believed. Something must be going wrong in the implementation.

    Are the measurements with the outlets etc. disconnected, or are they also connected to the wiring block?

    Are the two whites connected together still after the attempted paralleling? That would be problematic (and possibly rather spectacularly so).

    Also, are you sure you have the two whites associated with the coils correctly?
  • DPGBG's avatar
    DPGBG
    Explorer
    Aug 05, 2015
    as a little history, I replaced the 13 amp breakers fuses with 20 amp. I know the danger behind this but if this wont run my RV air then it does me no good. So with the 13 amp I could run RV air for about 10 minutes and it would trip the breaker. With the 20 amp it wont trip. I have about 5 hours on it now and as of now no problems. BUT... it's completely unbalanced. It's pulling max form one side of stator. I can only imagine this will shorten it's life probably more then the 20 amp breaker change. When air is running I can check the volts at the side the air is plugged into and its at about 108 volts and I can check the unused side and its at about 130 volts. So I'm guessing the AVR is trying to adjust for the draw on one side and over volting the other.

    If I can get parallel at 70% I would be happy as the draw will be from both limiting the major unbalance I have know.

    At least that was the plan.. lol
  • DPGBG's avatar
    DPGBG
    Explorer
    Aug 05, 2015
    What makes this generator different then the other parallel mods I've seen on the internet. Like the write up about the coleman powermate. Also 70% would be better then the 50% i'm getting now.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Aug 05, 2015
    You can do it but forget about getting 100% rated wattage out of the genset. A reconnected 4-wire 240 genset will render about 70% max wattage at 120vac. This is due to phase imbalance.

    Use a transformer and get 98% rated wattage TRACE ENGINEERING used to sell TOROID transformers 120/240 which can be configured either way. I use a Scott Connection transformer and tickler on the Kubota to render single phase from the 12-wire stator connection.
  • DPGBG's avatar
    DPGBG
    Explorer
    Aug 05, 2015
    Here is stock wiring.

    I have a 3200/4000 and it's in series so its really a 1600x2 . I run my RV with it and it's drawing all from one side. (unbalanced). I would like to wire it in parallel to get the full 3600 at 120 volts only.

    I have tried the usual coil 1 red to coil 2 white and coil 1 white to coil 2 black. I end up with 20 volts. I have been changing the wires at the terminal block, basically stacking them. I'm not sure if I need to change them after the terminal block though.

  • MrWizard's avatar
    MrWizard
    Moderator
    Aug 05, 2015
    You should be able to parallel the windings
    But you might need to disconnect the wiring, at the 220v socket
    And/or disconnect the wiring at the genset terminal block
    While you do your change over testing

    Take a picture off your wiring diagram from inside the manual
    And post it here
    Upload the picture to photobucket then post the "img" link in the post
  • j-d's avatar
    j-d
    Explorer II
    Aug 05, 2015
    DPG, I thought, like Matt, you wanted to parallel the Predator to another generator...

    So what is it that you DO want? I'm thinking you've got a genny that has 120VAC outlets at say 15-Amp each and you want one outlet 120VAC at 30-Amp. And you probably have a 240VAC outlet...

    If that's what I understand you want and what you have, I don't think you can do that, either.
  • DPGBG's avatar
    DPGBG
    Explorer
    Aug 05, 2015
    Matt, Not trying to parallel two generators. Trying to change the wiring on one generator from series to parallel. Thanks..

    There is more info on the topic 3000W Chinese gensets info.
    Go to newest threads cause this topic is huge and been going for years.
  • Matt_Colie's avatar
    Matt_Colie
    Explorer II
    Aug 05, 2015
    DPG,

    Paralleling AC generators is not all that tough if you have:
    A - an isochronous load sensing governor (you don't)
    B - an effective output voltage control (ditto)

    Give it a try, but one generator will want to take all the load.

    Matt

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