Sunny Island 6KW Generator not charging - Error fault code W351 and W319 - PLEASE HELP

DevonfarmsolarDevonfarmsolar Registered Users Posts: 2

I have installed a sunny island 3 years ago and generator still will not charge the batteries.  After a number of tests SMA (We are based in the UK and they have offered very little support) have offered to provide a new invertor but we want to ensure it is sunny island.

We have 2 x 3KW sunny boys feeding in solar power which works and a 6KW lister generator for power.  However the generator won't charge,

Below is an overview of the issues we have faced this far.  We would be very grateful if someone has any advice to get our farm supply working :)

I hired a 2,4 KW petrol generator and the invertor would charge the batteries.  However when I got GEM services (experienced generator / invertor technicians) to check the generator they found no issues.  They put in the new batteries but could find nothing wrong with it.  When they proceeded to try and make the SMA invertor work they were as mystified as the previous engineer

The engineer has 5 other customers who have the same generator with outback invertors and that works fine.  Also my Victron invertor charges batteries with the generator with no issue.  

When the generator is on, the invertor tries to synchronise with the generator and as soon as it tries to start charging, the generator voltage plummets to below 180V then fault code W351 and W319.  With all the following tests the same thing happens & the voltage drops so fast that the pitch of the generator engine does not change (about 2 seconds)

Tests carried out

  1. Disconnecting all inputs and outputs other than batteries (the generator live and neutral were the only connection)
  2. Disconnecting the earth / neutral connection to the generator
  3. Generator charging voltages and Hertz to make sure they were well within the invertor acceptable parameters
  4. Reducing the charging current for the batteries
  5. Testing the voltage dip on the generator when a 3 KW heater was put.  The impact was minimal

The only fault that could be found was that part of the date  on the data card was corrupted.  We then got a new data card (same size) and the data was also corrupted.  Would this cause any problems?

Below are Possible solutions for you to fix the problem:

  1. Get you to replace the invertor under the warrantee as you have offered.  However TBC if this would solve the problem as the existing one charged another generator
  2. Buy another generator – cheapest startomatic is about 2000 GBP, but how can I spent this money without knowing it could be the same problem.


  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Although unrelated to your situation, I have a single cylinder Kubota diesel  clone 5Kw generator which when used with an inverter welder, the voltage collapses when you try to strike an arc, this in turn quenches the arc making welding almost impossible. The solution was to use a voltage stablizer, this maintains a constant output voltage when there is a change, or introduced load. The inverter charger will have very similar rectification circuitry as an inverter welder including capacitor load, this is very different to a restive load such as a heater,  the generator has to play catch up to the initial voltage sag,, but being that the generator has no regulator to increase the fuel delivery,, the response time is too slow. If everything works with a generator with regulation, it is possible, I'm assuming the Lister is single cylinder with fixed throttle and large flywheel, that the reaction time is too slow and the inverter rejects the input as bieng too low a voltage. The welder works fine with a regulated generator so perhaps the problem is related. Just food for thought.

    BTW what do the error codes define?
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Dave AngeliniDave Angelini Solar Expert Posts: 6,294 ✭✭✭✭✭
    When you are offgrid you have to either have spares or competent service people. Over the years you may need both.
    I would think you could borrow a similar generator to test this. You are half way down the troubleshooting tree. Make sure your settings on the Sunny charger are correct and as wide as they can be set. 
    "we go where power lines don't" Sierra Nevada mountain area
    E-mail [email protected]

  • EstragonEstragon Registered Users Posts: 4,496 ✭✭✭✭✭
    I may not be looking at the right manual for your Sunny Island, but it shows W351 is an external short circuit on ac2 input code. W319 is overvoltage.
    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
  • EstragonEstragon Registered Users Posts: 4,496 ✭✭✭✭✭
    For test number 4, did you try the battery charging current set to a minimal value eg. 1A?
    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
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    With Lister's (or their clones) you have the Engine and the Alternator Head.
    You need 2hp for each KW of power, so my 6hp can drive 3Kw of electricity.  I have it connected to a ST-5 generator head, which helps handle any load/line imbalances.  And with the 650 RPM and a single cyl, there is a 5.5hz "wobble" in the Fq & voltage,  My XW6048 ramps it's loading up over the space of a couple seconds, which lets the generator "catch up"   From full load to no load, I have about 6 Hz sag,  Voltage on my ST-5 with self-excited harmonic winding ends up being quite stable, but the ST heads are reported to have a bit of a distorted waveform.
     So tell me more about the engine and alternator and I can help narrow it down,
     I have wide acceptance settings on the inverter to prevent nuisance drop-offs, and I ramp up charging load slowly as the engine warms up.
    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: ,

  • DevonfarmsolarDevonfarmsolar Registered Users Posts: 2
    Hi all,

    Thank you for your above advice.

    After much back and forth with SMA and technicians visiting, the problem was solved with 1 setting change! I am not at home but if interested I can share the exact detailed info,
  • BB.BB. Super Moderators, Administrators Posts: 32,921 admin
    If you can let us know the change--It would be nice for others whom may experience the same problem  in the future.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SaltsSalts Registered Users Posts: 1
    The setting change was probably that he had to tell the Sunny Island that the AC2 terminal was being powered by the generator and not the grid.   It can take either, but it has to be told which it is.    There's a setting for it.  19.2.3 External Settings in the Sunny Island 6048.  Value 05 (external source).    I think the Sunny Island opens up the frequency and voltage limits when in Gen mode because most generators run kind of sloppy.      That's my guess anyhow.     His generator was probably tripping the over-voltage setting whenever a large load was turned off and the governor took a second to stabilize it again.    

    I'm just guessing.
  • mustondownfarmmustondownfarm Registered Users Posts: 1
    Can you please tell me what setting was changed, is it in the parameters ac or grid monitoring. Or somewhere else. I have the same problem with a hyundia 5kw generator.
  • BB.BB. Super Moderators, Administrators Posts: 32,921 admin
    Devon has not been back in 4 years... You might try sending a PM (private message) and see if he replies.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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