Conext SW 4048 inverter

Issue - inverter energizes for a few seconds then powers off. 

System is as follows
48v, 100ah lifepo4 battery
Schneider electric Mppt 60/150 charge controller
Conext SW 4048 inverter
Midnite solar e-panel
9, 320w solar panels - 3 strings with 3 panels each
Combiner box for PV
SCP for the inverter
Conext gateway combox

All wiring has been completed per the wiring diagram provided by schneider electric. Closing the breaker to energize the charge controller, the charge controller energizes appropriately.

 When I close the breaker to energize the inverter (with the charge controller energized) the inverter energizes for a few seconds then powers off. Multimeter reads 55.4v on the inverter breaker terminal before closing inverter breaker. Once closed, voltage rapidly drops to around 3v. Battery support said this behavior is by design when the battery protection mechanism engages. 

Battery monitor shows a spike at the point of the breaker closing. Then Sharp drop.

If I leave the charge controller off and close the breaker to the inverter, inverter powers up.

In addition, I have the SCP attached to the inverter via the xanbus connection. If I also connected the conext gateway combox via the xanbus, the same behavior is displayed. Inverter energizes for a few seconds then powers off.

So this looks to me like I don't have enough power supplied to energize all the equipment. I've been looking for troubleshooting/diagnostics information on the inverter but haven't been able to find anything other than the install guide.

Charge controller appears to be functioning properly as it shows bulk, float, and absorption charge appropriately. 

Thanks for any assistance

Comments

  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    When the battery is connected to the inverter initially it draws high current to charge the capacitors, this may be higher than the BMS will tolerate thus disconnects the load, most likely case.  
    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.
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Try getting/using a 250w incandescent Flood Lamp and use that too slowly precharge the inverter capacitors.  it  may wake up and complain about low voltage, but eventually power on, and  THEN flip the breaker

    Batt +  ----------- 120V 250W flood lamp  ----------------- + inverter input

    The idea is to bypass the breaker and allow the  flood lamp to limit current flow till the caps get charged up to 24v.

    But you have a bigger issue,  Your inverter is way larger than your small Li battery can safely support.  you may be triggering the battery BMS several times a day - won't that be fun.
    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 ,

  • PhazorPhazor Registered Users Posts: 2
    edited May 2021 #4
    Issue - inverter energizes for a few seconds then powers off. 

    System is as follows
    48v, 100ah lifepo4 battery
    Schneider electric Mppt 60/150 charge controller
    Conext SW 4048 inverter
    Midnite solar e-panel
    9, 320w solar panels - 3 strings with 3 panels each
    Combiner box for PV
    SCP for the inverter
    Conext gateway combox

    All wiring has been completed per the wiring diagram provided by schneider electric. Closing the breaker to energize the charge controller, the charge controller energizes appropriately.

     When I close the breaker to energize the inverter (with the charge controller energized) the inverter energizes for a few seconds then powers off. Multimeter reads 55.4v on the inverter breaker terminal before closing inverter breaker. Once closed, voltage rapidly drops to around 3v. Battery support said this behavior is by design when the battery protection mechanism engages. 

    Battery monitor shows a spike at the point of the breaker closing. Then Sharp drop.

    If I leave the charge controller off and close the breaker to the inverter, inverter powers up.

    In addition, I have the SCP attached to the inverter via the xanbus connection. If I also connected the conext gateway combox via the xanbus, the same behavior is displayed. Inverter energizes for a few seconds then powers off.

    So this looks to me like I don't have enough power supplied to energize all the equipment. I've been looking for troubleshooting/diagnostics information on the inverter but haven't been able to find anything other than the install guide.

    Charge controller appears to be functioning properly as it shows bulk, float, and absorption charge appropriately. 

    Thanks for any assistance

    Did you get this resolved? If so what did you do? I have a very similar setup that I have not completely installed yet. I have a 48v 165F Maxwell ultracapacitor that i was going to use in parallel with my Lifepo4 battery bank. But I haven't installed anything yet and I am still figuring out how to implement everything the best way possible. Would really like to hear what you did.
    I found this on another site as well:

    When the inverter starts up, there is a large start-up surge for a second or two so that the inverter can charge up its capacitors.

    When the inverter was originally designed around a lead acid battery, lead acid batteries have a higher internal resistance, so the lead acid batteries resistance will slow down the surge, however lithium batteries have a very small internal resistance compared to lead acids, so the inverter is wanting to pull in a massive amount of energy to charge up the capacitors, but the lithium battery won't deliver.

    There are some lithium battery manufacturers that have built-in a pre-charge resistor in their battery that will add a high level of resistance to slow down the start-up surge required to charge the capacitors. They might run the battery current through a resistor or relay for the first 3 – 4 seconds.

    Schneider recommends a 250A circuit breaker which will provide a means of disconnect (your overcurrent protection) that protects the wire between the inverter and the battery.

      
  • Dave AngeliniDave Angelini Solar Expert Posts: 6,304 ✭✭✭✭✭
    Too small of a battery to be useful offgrid, no matter of the chemistry. A name brand LFP battery system has already solved this issue and will support you. A DIY battery that is half baked is often the cause of these basic problems. I have seen them too often when called for support. I shake my head! I 

     It is basic that the battery and inverter work together and can start inverting offgrid.

    The Schneider breaker is also designed for protecting a bad battery.  A small battery may not be able to trip the 250A. It better have it's own means to protect you from a fire. Good Luck!
    "we go where power lines don't" Sierra Nevada mountain area
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

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