Crazy Voltages to AC Input from Generators

Hi, new here, glad to be here!

I posted this on another forum, but still needing help, input or insight on this.

I am new to the Solar Power System world but I have a remote Swamp Camp and I had some money saved so I thought I would buy a System because parts of the year no AC is needed. I got this system in the 4024 Version. I have 4, 6 volt Trojan L16 RE-B for my storage.

Now I have 2 Generators at my Camp. A Westerbeke 4.5 KW and an Onan DJE 6.0 KW. I like redundancy  Both of these Gensets run fine and produce at 60 HZ, and 122-124 volts 
I know Generators very well, and I am no novice when it comes to electrical connections.

Now the Crazy part. When I have the Westerbeke connected with out the AC Input Breakers on I read the voltage in the panel at AC In and it is 122-124 volts. I flip the breakers on the panel it bogs down the Genset, and the voltage rises up to 160 volts or so and the breaker trips.  I see the Charging light come on with this Genset connected.

Now when I have the Onan connected it does the exact opposite. A good 122-124 volts at the AC In, flip the breakers on the panel it does not bog down the Genset and it drops to 8-5-9.6 volts. I do not see the Charging light come on with this Genset.

I set the AC input Amps in the Inverter Controller to 15. The Westerbeke puts out 19 each leg and the Onan 25 so I thought that would be a good start for that setting.

Not sure if anyone has ever saw this type thing, or have any ideas, but they are all appreciated 

I have since been to my Camp and I isolated it from the System.  I get the exact readings mentioned here as I did the first time around, so it has to be in the System I bought. 

I want to add that both of these Gensets run my Camp with no issues, and it appears the Solar System itself works fine in running things in my Camp.


South of New Orleans


  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Are your measuring the gensets with no loading, or with a normal load ?
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Are the gensets FLOATING and the Solar grounded or visa versa?
    How does the solar system work?  what is the interface between the two AC systems, bypass switch? or lockout ?
    I woulds suspect a short / bad connection somewhere.  Did you use a torque-screwdriver?
     All connections made with a hydraulic crimper, fitting is attached have heat shrink?
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Viking66
    Viking66 Registered Users Posts: 3
    I am thankful and happy to receive some replies that have me thinking!!!  My Camp is not accessible by road so any ideas or suggestions may take some time for me to try since I can usually just get out there once a week on the weekends, so bear with me on that :)

    I am measuring the Gensets with no load, just seeing what they were out putting to the AC Input locations in the panel.

    I bought the System pre-assembled as far as the Panel, Inverter, the inverter remote controller, and the Solar Charge Controller.  They came mounted on a board as one.  It does show they used heat shrink, not sure on the torque screw driver, but possibly.  I myself do not own one, but always ensure I make good tight connections when I wire up things to a panel.

    The System has one ground for the Camp and the Solar System.  I un-bonded the neutrals on the Gensets and have just one neutral to ground bond for the entire system.  The Gensets are connected to the entire system grounding point through the wiring panel, as is everything else.

    Both the Solar System, and Generators work fine independently.  I can look through and see what pics I have of the box internals if that would help, but as it came, they were clearly labeled.

    Thanks again.  I am not a wuss so if you think I got something wrong, let me know.  My goal is to have this working correctly and get all of the features I paid for!!!!
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I'm a bit confused on how your generators and inverter are set up. For example you said the Onan puts out 25a on each leg. Is it wired for 120v or 120/240 split phase? A 6kw generator would be 6000/120=50a, or 25a per leg at 120v, but 6000/240=25a total at 240v. The voltage you mentioned being 122-124, which I assume is line to neutral? If so, what is line to line voltage?

    I'm sort of wondering if the inverter is set up for 120/240 split phase input, and the gennies are wired for 120v single phase output, or maybe vice-versa.
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • Viking66
    Viking66 Registered Users Posts: 3
    It is setup as a 120/240.  I was going with what was in my head on the 25 Amps per leg on the Onan.  I agree it would be 25 at in a hurry I guess.  The readings I mentioned were from line to neutral.  They were doubled line to line.  The Inverter is a 120/240 split as is the box for connecting it all together.

    Inside the box there are 2 AC Input a Neutral, Ground.  AC Out has 2 AC Out connections, the neutral and ground are used by both.  It looks like this inside (See Link to pdf) but with 2 #18 for AC IN, and 2 #@0s for AC Out.

    Thanks for all of the extra sets of eyes on this!!!