Stacking Two Schneider Electric SW-4048 Inverters Failure

neutronspin
neutronspin Registered Users Posts: 51 ✭✭
I recently installed two Schneider SW4048 inverters and their stacking kit.  Configured one as master and the other as slave.  The system ran perfectly except when I decided to power down the system for some maintenance.  I started the system per their instructions and I heard a loud clunk from one inverter and it threw an error code that the Master inverter failed.  I attempted to restart the inverter and it was dead.

I then contacted Schneider Solar tech support to get a replacement inverter since it was less than two months old and under warranty.  Surprisingly I was informed that Schneider pulled their inverter stacking kit off the market and they are now telling me that they can't be stacked.  Although they still say stacking is acceptable in their current literature.  Am I being hoodwinked by them or what?  They said run them separately or nothing and they can't even share a common battery bank even if the outputs were separate.

Is anyone running these inverters in parallel?  And is it successful?  I would caution anyone who purchases two of these inverters and want to stack them to ask questions.  I am now stuck with my purchase and my only option is to go with an XW+6848 inverter or abandon Schneider altogether.  I will be stuck with their switchgear and other support equipment if I decide to do this.....any info appreciated.   Thank you....

Comments

  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    I will ask Engineering and be back later today, if the fog lifts....
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Let's suppose you bought a four wheel drive truck which the manufacturer claimed would get you out of the mud, snow or whatever, but later claimed the four wheel drive in fact didn't  work and you would need to buy a second truck, that would have to be driven by a second driver to achieve four wheel drive, only it wouldn't work as advertised. A recall would be issued to address the shortcomings, and the truck would be either replaced or repaired to meet the claimed performance, not an up sale to a higher model. As a consumer there are specific rights which protect one aginst  fraudulent advertising, but in reality I think  tech support is only a frontline, the matter will be better dealt with those higher on the food chain. Don't give in prematurely, Schneider will support you, eventually. Usually the vendor is the go between with regards to warranty claims, they at very least, should peruse the matter.
    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.
  • Horsefly
    Horsefly Registered Users Posts: 470 ✭✭✭✭
    Maybe I'm misunderstanding, but if Schneider says they have pulled the stacking kits, why is it still available from the host of this board?

    https://www.solar-electric.com/schneider-electric-sw-conext-ac-stacking-kit.html

    Off-grid cabin: 6 x Canadian Solar CSK-280M PV panels, Schneider XW-MPPT60-150 Charge Controller, Schneider CSW4024 Inverter/Charger, Schneider SCP, 8S (25.6V), 230Ah Eve LiFePO4 battery in a custom insulated and heated case.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    Just to clarify, did you install both the stacking kit and the interlock/breaker box (sold separately)?  

    Without the interlock, it would be possible to put bypassed AC onto the inverter AC output, in which case the resulting release of magic smoke likely would void warranty

    Just a thought.
    Off-grid.  
    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
  • neutronspin
    neutronspin Registered Users Posts: 51 ✭✭
    Estragon said:
    Just to clarify, did you install both the stacking kit and the interlock/breaker box (sold separately)?  

    Without the interlock, it would be possible to put bypassed AC onto the inverter AC output, in which case the resulting release of magic smoke likely would void warranty

    Just a thought.

    No....I installed their stacking kit per their installation manual.  The kit provides a new interlock plate and breakers to use in the parallel mode. They worked in the stacking mode for a day fine but when I turned the system down for maintenance and restarted both inverters per their instruction sequence I got a code that stated the Master Inverter Lost.  From what I understand both inverters must communicate with each other in order to put them in parallel.  If they loose communication bad things can happen.  I assume this is done over the XANBUS.  The old original Xantrex design used a stacking cable to accomplish parallel operation which connected between the two inverters.  It is like bringing a gen set online and synchronizing it to the grid.  If they are out of sync bad stuff can happen.  I don't know what happened just the code# 75 Master Inverter Lost.  After that the Inverter was dead.  I lost all confidence in the inverters to do as they were designed.
  • neutronspin
    neutronspin Registered Users Posts: 51 ✭✭
    Horsefly said:
    Maybe I'm misunderstanding, but if Schneider says they have pulled the stacking kits, why is it still available from the host of this board?

    https://www.solar-electric.com/schneider-electric-sw-conext-ac-stacking-kit.html


    This is what their support said that they will not continue the stacking kit.  Don't know if they pulled them off their vendor network stock or even if this is true.  This is what I was told....Also I was told that stacking won't work although they have it in their current Installation manual....
  • neutronspin
    neutronspin Registered Users Posts: 51 ✭✭
    mcgivor said:
    Let's suppose you bought a four wheel drive truck which the manufacturer claimed would get you out of the mud, snow or whatever, but later claimed the four wheel drive in fact didn't  work and you would need to buy a second truck, that would have to be driven by a second driver to achieve four wheel drive, only it wouldn't work as advertised. A recall would be issued to address the shortcomings, and the truck would be either replaced or repaired to meet the claimed performance, not an up sale to a higher model. As a consumer there are specific rights which protect one aginst  fraudulent advertising, but in reality I think  tech support is only a frontline, the matter will be better dealt with those higher on the food chain. Don't give in prematurely, Schneider will support you, eventually. Usually the vendor is the go between with regards to warranty claims, they at very least, should peruse the matter.
    I hope you are correct.  I have spent a considerable amount of time and expense in setting up my off-grid system.  A recent brand new 7.2Kw rooftop professionally installed array and four of their inverters and other Schneider Electric support equipment over time.....
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    This is what I was told.

    "Really appreciate you bringing this is to our attention. It certainly does seem we've got some information gaps to fill on CSW. Yes we did have some firmware issues that lead to some hardware reliability problems on CSW and we did communicate that we were not supporting stacking while we were working on fixing it. However it is all fixed now and I don't think we've done a very good job getting the messaging out there that it's ok now."

    So, If I were you I would go back to my vendor and get them to do something with support. From what i can tell the firmware needs to be latest and often people add the second Inverter later and may not have updated the firmware.

     

    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • neutronspin
    neutronspin Registered Users Posts: 51 ✭✭
    I will ask Engineering and be back later today, if the fog lifts....
    Thank you....I have a
    This is what I was told.

    "Really appreciate you bringing this is to our attention. It certainly does seem we've got some information gaps to fill on CSW. Yes we did have some firmware issues that lead to some hardware reliability problems on CSW and we did communicate that we were not supporting stacking while we were working on fixing it. However it is all fixed now and I don't think we've done a very good job getting the messaging out there that it's ok now."

    So, If I were you I would go back to my vendor and get them to do something with support. From what i can tell the firmware needs to be latest and often people add the second Inverter later and may not have updated the firmware.

     

    Thank you for the reply.  I have opened a case with Schneider Support and hopefully they will send me a replacement inverter.  I must have misunderstood what was said from the support staff person but I was in the dark until you explained the issues and resolution.  They said they will replace the inverter and hopefully I can get my system up and running again.

    I do have a question as to the firmware updates.  Does this include the ComBox and my MPP60-150 controllers and the rest of the support equipment?  I assume the latest firmware is on their website for download.  I replaced my two original SW4024 inverters with these 48 volt units as I upgraded my battery bank to 48Vdc. As I stated in other posts these inverters performed flawlessly until the Master failed. 

  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,728 ✭✭✭✭✭✭
    You are welcome. You must always have a number with Schneider, Always. They are huge and will lose you in the noise without a case number.

    If you are full time offgrid in my opinion, you should be using the xw+ series. They are built for longer life and the warranty reflects that. They are also field tested more, mature, and are the one to use for critical power.

    You should hear the stories I am hearing lately about Outback so keep calm.

    The mppt-60 is mature and there really is not much firmware that would cause your issue. The CSW does not need a combox so that is not the source here. I think that you had 2 different firmware builds in your 2 CSW's. It worked until it did not. They will walk you thru it or replace the CSW. All the firmware is on their website and it has release notes with what they fixed, or attempted to ;)

    Good Luck
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • neutronspin
    neutronspin Registered Users Posts: 51 ✭✭
    You are welcome. You must always have a number with Schneider, Always. They are huge and will lose you in the noise without a case number.

    If you are full time offgrid in my opinion, you should be using the xw+ series. They are built for longer life and the warranty reflects that. They are also field tested more, mature, and are the one to use for critical power.

    You should hear the stories I am hearing lately about Outback so keep calm.

    The mppt-60 is mature and there really is not much firmware that would cause your issue. The CSW does not need a combox so that is not the source here. I think that you had 2 different firmware builds in your 2 CSW's. It worked until it did not. They will walk you thru it or replace the CSW. All the firmware is on their website and it has release notes with what they fixed, or attempted to ;)

    Good Luck

    Hello,
    Schneider Electric replaced the inverter and we are back up and running great....hats off to Schneider....thanks again....
  • jtdiesel65
    jtdiesel65 Solar Expert Posts: 242 ✭✭✭
    I've used the sw4024's and eventually (after like 5 replacement inverters) schneider sent me two xw and never had a problem since. IMO the sw's are buggy when stacked. Here's my thread on my issues  https://forum.solar-electric.com/discussion/20058/fried-conext-sw4024#latest

  • neutronspin
    neutronspin Registered Users Posts: 51 ✭✭
    I've used the sw4024's and eventually (after like 5 replacement inverters) schneider sent me two xw and never had a problem since. IMO the sw's are buggy when stacked. Here's my thread on my issues  https://forum.solar-electric.com/discussion/20058/fried-conext-sw4024#latest


    Hello....thank you for the reference thread.  The similar thing happened to me as well.  The instructions for the stacking kit had the output neutrals tied to the input neutrals I believe.  I also had some firmware issues as well.  Now both inverters have been running good for now but I have not tried to run the input with my genset.  I am using AC grid support now.  Am scared that it may destroy another inverter.  I am going to research further into this.  Also I am contemplating adding a relay on the AC inputs to remove the AC at a specified SOC from my MPPT controllers since the "consumption" mode doesn't work very well...I noticed today since there hasn't been much solar input my battery bank is at 67% SOC and the charger has not come on in either inverter.  They both have chargers enabled and the recharge voltage is set on both to 50 VDC.  Battery voltage is at 47.3 VDC and neither charger is on.  I am sorry I have these inverters now and would jump at the chance to replace them with the XW+ but it won't happen.

  • grmln01
    grmln01 Registered Users, Users Awaiting Email Confirmation Posts: 1

    I recently installed two Schneider SW4048 inverters and their stacking kit. Configured one as master and the other as slave. The system ran perfectly except when I decided to power down the system for some maintenance. I started the system per their instructions and I heard a loud clunk from one inverter and it threw an error code that the Master inverter failed. I attempted to restart the inverter and it was dead.

    has there been any resolution to this issue...….I tried to start two stacked sw4048 inverters last night and got fault codes referencing ac outputs are out of phase thought that I should up date all firmware but now after reading this thread I may need to quite before I burn something up...…….

  • MrM1
    MrM1 Registered Users Posts: 487 ✭✭✭✭
    edited April 2019 #16

    I think the firmware of the SWs has to be latest or it is likely not to work well.


    I've looked at the list of improvements in the latest firmware, but have been reluctant to update Bc it does not look like anything that will benefit a single SW in my configuration.

    REC TwinPeak 2 285W 3S-3P 2.6kW-STC / 1.9kW-NMOT Array / MN Solar Classic 150 / 2017 Conext SW 4024 Inverter latest firmware / OB PSX-240 Autotransfomer for load balancing / Trojan L16H-AC 435Ah bank 4S connected to Inverter with 7' of 4/0 cable / 24 volt system / Grid-Assist or Backup Solar Generator System Powering 3200Whs Daily / System went Online Oct 2017 / System, Pics and Discussion