Conext XW+ 6848 trouble with the generator

M CuzM Cuz Registered Users Posts: 4
Hi, I just installed a new Conext XW+ 6848 NA but I have trouble with the generator. I have a type 2 generator connected to the inverter and I’m using a SCP with a AGS. The problem starts when the generator kicks in, I can see the number going from 10 to 100 in just seconds and then the inverter goes to stand by(- - - ), after a few second it will start the charging again and the number keeps saying that the charge is 100% in just seconds and then the loop starts all over again.

Any help will be welcome

Comments

  • BB.BB. Super Moderators Posts: 26,872 admin
    Welcome to the forum!

    I am not any sort of expert in these off grid systems... But my first question would be the Battery Connections. Are the wires well attached (connector screws torqued properly)? What gauge/size of copper wiring are you using (battery connections, battery to DC panel, DC Panel to inverter, etc.)?

    It sounds like the DC Bus voltage is not stable (poor connection and/or too small of diameter wiring).

    Does the inverter work otherwise (i.e., can you turn on the inverter and run some subtancial AC loads--Like a 1,000 Watts or more of electric heater--as a simple load)? Can you measure the battery bank voltage and the DC Voltage at the Inverter's DC input?

    Anyway, my first guesses.

    Also, what size/type battery bank do you have? How many series/parallel batteries? With Lead Acid batteries, you need to get those charging so they do not excessively discharge and sulfate. Do you have some sort of good quality hydrometer to measure specific gravity?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    As B.B has requested more information on your battery bank capacity. Will determine what charging limits need to be set with the SCP. Wiring to/from batteries to inverter. Will need the capacity Watt output of your generator. Can effect Gen/Support settings if they need to be limited. Breaker sizes, need to be set thru SCP. State of Charge of battery bank, if charged or close may be throwing too much current at them, voltage rise to cutout, then voltage drop and then charge again. charging parameters need to be tailored to Bank Capacity, need a pretty large bank to handle the 140 amp DC charging of the 6848 charger.
    Lots of adjustability built into the Inv/Charger just need to be adjusted from Defaults set at factory.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • M CuzM Cuz Registered Users Posts: 4
    Hi, guys, first thanks for your help, now I have two battery banks each with 8 six VDC batteries in series and both of them connected in parallel for a 48 vdc battery bank. Wiring from and to the batteries is gage #2 with very short distances. My generator can go up to 8500 k peak and 6500 on a normal run. Everything works fine, on a sunny day my PV array produce enough energy to run one 7 amps 220 VAC water pump, which draw 20% of the 6848 capacity, and keep the batteries charge. Forgot to mention I’m a farmer, I have a 10,000 square foot hydroponic system.

    Thanks in advance..
  • BB.BB. Super Moderators Posts: 26,872 admin
    What is the Amp*Hour (20 hour rate) of the batteries/battery bank?

    Do you have a solar array/AC utility power?

    Most of these inverter/chargers can be adjusted. Maximum DC Charging current (sometimes entered as maximum AC current for charging--Confusing). Also, there may be an AC1 and AC2 input. AC1 is generally for utility power and AC2 is a wide range (frequency/line voltage) for Backup AC genset input.

    Sometimes what happens is the line frequency (generator RPM) varies so much that the inverter/chargers will have a difficult time "qualifying" the frequency (+/- 0.5 Hz vs +/- 3-5 Hz) or line voltage.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    XW charging can be controlled via setting the limit in percentage of the 140 amp capacity of the charger. Your 8500/6500W generator can drive it to that output. Take a large bank to require that. Was the bank size entered into XW during setup. AC2 breaker size entered. You can set the amp value that you want to be the MAX current drawn by the XW from the generator. As B.B. Ask'd need the bank capacity to help suggest a setting for charging.
    I would also, suggest that you change out the #2 ga wire with #4/0 ga wire and that is recommended not to be greater than 10 ft by Schneider for that inverter, with a 250 amp breaker.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • M CuzM Cuz Registered Users Posts: 4
    BB

    Hi, my amp hour rate is 140, I have a solar array to charge the batteries and AC! (power company, it will be disconnected as soon as my generator works) no AC2. On the test I did the AC! Was disconnected only PV arrary and generator were connected.

    Skidoo

    I do not recall enter the battery bank size on the XW or AC2 breaker size.

    Thanks
  • BB.BB. Super Moderators Posts: 26,872 admin
    A 140 AH battery bank (flooded cell type) is a awfully small battery bank for a 6.8 kWatt AC inverter.... In general, if you plan on running the inverter at full power (6.8 kWatts), the battery bank should be closer to 680 Amp*Hour @ 48 volt capacity.

    And the rate of charge should be something around 14 amps to ~28 amps @ 48 VDC or so for that size battery bank.

    I am not sure, but that size inverter-charger can probably do something near 100 amps of battery charging current... Way to much for such a small battery bank.

    Are you sure your battery bank is 140 Amp*Hours @ 48 volt capacity? Maybe there is some confusion about what I am asking about?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    He might have 280 amp/hr think he said he had 2 parallel strings? XW is capable of 140 amp charge output. His charger settings need to be set to 10 to 20 percent. Set in percent of charger capacity. Agree needs bigger batteries higher capacity batteries. I have 370 a/h @ 24 VDC on a XW 4024 and if I was using on Off grid then my battery bank is way to small. Mine is for occasional essential power when grid goes down. Not very often 3.5 hr total so far this year none last year. Also, need to set total bank size thru setting or SCP has effect on absorb times end current etc.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • M CuzM Cuz Registered Users Posts: 4
    Hi guys; That is right I have 2 string of 8 6vdc batteries and with that I run 1 water pump(8 to 6 hours a day) that draw 7 amps at 220 vac. I know that my battery bank is small, but the idea is to grow my hydroponic and at the end I’ll be needing the power to run 5 pumps so when the time and $$$$$ comes I’ll increasing the battery bank size. I’ll configure SkiDoo’s settings today and let you know the outcome.
    Thanks for your time
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Due you have generator support turned on? You can set the limit on what the inverter will pull as max, charging and pass thru to loads. It can deliver power to load and charge at the same time. I would target that setting to be @ 80% of the 6500W rating to keep the frequency and voltage regulation getting large surge loads to it. You can adjust your charger settings to what will provide stable operation. Best to start low and work up to what provides the best results. Charging current should be around the 10% of amp/hr capacity of the bank. Bulk charge with gen and let solar finish it. B.B and others can offer more experience with the daily care of charging and help with the setting to maintain battery health as they live on the battery daily. Due wish the XW manuals had more and clearer explanation of the settings and what hey do. Could solve a lot of mistery and frustration, complaints about them. I love how mine is working. You can send request to tech support, they normally get back within 24-48 hr via email.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • BB.BB. Super Moderators Posts: 26,872 admin
    Actually, I am on Utility/Grid Tied--I do not have any off grid solar... Just a small backup genset (if I ever need it).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    BB. wrote: »
    Actually, I am on Utility/Grid Tied--I do not have any off grid solar... Just a small backup genset (if I ever need it).

    -Bill
    I stand corrected for some reason thought you were off grid. My XW is set grid support/sell. Every couple of weeks I simulate a grid failure (shut off AC1 breaker) and let it feed the panel from inverter to exercise batteries. Guess I need to figure out who I was thinking of that is off grid.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • BB.BB. Super Moderators Posts: 26,872 admin
    No problem... I try to help everyone (within my limitations).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    M Cuz wrote: »
    Hi guys; That is right I have 2 string of 8 6vdc batteries and with that I run 1 water pump(8 to 6 hours a day) that draw 7 amps at 220 vac. I know that my battery bank is small, but the idea is to grow my hydroponic and at the end I’ll be needing the power to run 5 pumps so when the time and $$$$$ comes I’ll increasing the battery bank size. I’ll configure SkiDoo’s settings today and let you know the outcome.
    Thanks for your time
    Any update? Checking to see if adjusting the settings enabled the gen to stay on and supply power to loads and charger.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • mike95490mike95490 Solar Expert Posts: 7,307 ✭✭✭✭
    A new thought,
    Connect your generator to AC2 (which is where it is supposed to go, not AC1 which is Grid) Use the SCP to program your total battery AH size (2 parallel 48v strings, maybe about 300Ah your post was not real clear) You should have about a 600ah battery to support that size of inverter. Then use the SCP to program AC2=40A, GEN support to 25A, GEN Support Plus Enabled, and max charge rate 50%. (you can see some example in Col D below, I have to remind myself of the settings when I reboot). All these settings are in different menus on the SCP, and I think some are in the Advanced menu that needs a 2 button press & hold to enter.
    Deep in the manual, are the definitions of the setting meanings. Some are AC L1 & L2 some are AC L1, some are DC, Some have internal 20% derate, But what I gave is 2x what my 3Kw genset is happy with, so your 6Kw genset should be fine too. Get it working then start tweaking it. The Combox comes in handy to see the actual loading in real time, and I use the SCP to tune things.

    Oh, and 2ga wire seems too small for any battery connected to the inverter.

    Attachment not found.
    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

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Schneider does not recommend Gen Support Plus being "ON"with a generator over 5KW size. Recirculating currents.
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    SkiDoo55 wrote: »
    Schneider does not recommend Gen Support Plus being "ON"with a generator over 5KW size. Recirculating currents.


    True but the user should try it as this can be difficult to get going offgrid with a hybrid inverter like the XW. When it was new in 2007, it was the thing that made me give up on generators and go completly solar. I have many customers who live in places that need a generator or they just have not had the time to learn how to use less energy when solar weather is bad.

    In some cases I just tell the person set the incoming AC2 amps to below the gen spec, widen all AC specs to max, and set the charge percentage to keep any AC loads from causing problems. Also the first hour should be for battery charging if you have a 6KW or less generator. Watch the DC amps on the SCP start dropping, it is telling you that the batteries are charging and there will be more power available for AC loads.

    The old joke, there are two kinds of people, those who want solar and those who want more.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

  • AimsmallAimsmall Registered Users Posts: 9 ✭✭
    Hoping not to hijack this thread, but I'm having a similar, but inverse issue with a 6848. I've got 1000 ah @48 vdc on 4 strings of 8 6 volt batteries, charging well on PV, but since I need to bring the other array online, I'm trying to get generator charging operational in this off grid system. Connecting the Gen as prescribed in the wiring diagram, through the 60a breaker in the PDP, when AC power is applied, then qualified, the unit switches to charging, and amps (per the LCD) climb steadily to over 100, bringing the Gen to its knees, then and internal breaker or relay opens, and it stops trying to use the incoming AC. From what I've read in this thread, Gen support may resolve this issue. Am I on the right track?
  • mcgivormcgivor Registered Users Posts: 1,304 ✭✭✭✭
    Always best to start a new thread specific to your system including as much detail as possible, generator capacity is essential to make a suggestion, from limited information, 100A at 48V+ is 4.8 Kw, so the generator would have to be larger than this value, perhaps 30% larger , ~6.5 Kw.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • AimsmallAimsmall Registered Users Posts: 9 ✭✭
    > @mcgivor said:
    > Always best to start a new thread specific to your system including as much detail as possible, generator capacity is essential to make a suggestion, from limited information, 100A at 48V+ is 4.8 Kw, so the generator would have to be larger than this value, perhaps 30% larger , ~6.5 Kw.

    I realized that this was an old thread, and did add this question to a thread I already have going on the myriad issues I've encountered so far: http://forum.solar-electric.com/discussion/352481/fried-xw6848#latest
  • Dave AngeliniDave Angelini Solar Expert Posts: 3,329 ✭✭✭✭
    When in doubt read the manual? It is not the 60a breaker that are concerned with but the XW AC settings screen and its "breaker size setting.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail offgridsolar@sti.net

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