Fried 2nd Xantrex GT in < 1 year

aj164aj164 Solar Expert Posts: 109 ✭✭✭
One of our customers now has a 2nd bad Xantrex GT inverter. We installed a replacement from Xantrex just last October. The symptoms are the same:

The inverter displays "AC Voltage Fault", but the voltage and frequency readings on the display (and DMM) are well within spec. Both line-to-neutral readings are also perfectly normal.

The model is a Xantrex GT3.3-NA. We have two strings of nine BP 175W panels (18 modules total @ 3.15kW). The DC voltages on each string look normal.

The inverter will connect on occasion throughout the day. Total runtime might be about two hours / day. The old GT3.3 did the same thing...

With the old inverter, I could force it to connect by turning it off and back on. This one immediately displays "AC Voltage Fault" when I turn it on.

If I turn off the AC disconnect, the message changes to "AC Voltage Fault 0.0V". When I turn the AC back on, the "0.0V" goes away.

I will try to get a 3rd replacement, but anyone have any ideas what this could possibly be (besides just another wacky inverter)?

Thanks -
AJB

Comments

  • SkiDoo55SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year

    I am not an expert but by the sounds of it and that this is the second inverter that is displaying the same problem, I would check all of the AC side connections from main panel to the inverter. Could have a corroded/loose connection on a breaker, disconnect switch externa (if Installed) or internal one in inverter. These inverters use the Phase to neutral for voltage sense. If that is all good appears that there may be a utility grid problem or something close proximity could be interferring. Haven't heard of too many problems with the GT inverters on forum, other than support is hard to get ahold of.

    I am installing GT3.8, ( Phase #1 first half) should be online by end of July, pending PG&E in CA.
    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!!
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year

    Sounds more like a grid power quality issue than a bad inverter, especially since two unit are doing the same thing

    I'd suggest you use either GT-View or SG-View with a PC to log the inverter parameters for a day or too and that should show exactly why the inverter is disconnecting.

    GT-View
    http://www.xantrex.com/web/id/2584/docserve.aspx

    SG-View
    http://www.solar-guppy.com/forum/sg-view-xantrex-gt-gridtie-pc-monintoring-software-t548.html
  • solarixsolarix Solar Expert Posts: 713 ✭✭
    Re: Fried 2nd Xantrex GT in < 1 year

    I concur on it being an actual problem with the grid AC. DMM's or voltmeters can miss a lot of noise or distortions on the waveform. Need to look at it with an oscilloscope or line analyzer. Inverters are fairly picky about AC quality due to the requirement to shut off when the AC goes down. Remember that utilities have pretty loose requirements on power quality. Fail safe = success difficult.
    If you can prove its a power quality problem, you might be able to get help from the utility. If not, adding inductance to the line will smooth it out. 4kW transformer sitting between the inverter and the line isn't too expensive, could even be an autotransformer, or might be enough to wind a few loops of your AC conductors through large ferrite rings. Let us know what works. This is potentially a common problem (many people might have it but not know it) and we haven't heard it happen much.
  • aj164aj164 Solar Expert Posts: 109 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year
    I'd suggest you use either GT-View or SG-View with a PC to log the inverter parameters for a day or too and that should show exactly why the inverter is disconnecting.

    I wrote my own program to do this. I use it on the GT inverter at my house. (I am just down the street from the customer, by the way.) I had the idea to get a log, but I couldn't get the inverter to connect at all (despite all measurements appearing to be within range.)

    It seems like the inverter is bad. Maybe something at the site caused the problem, but the inverter won't even try now with good power. It would be helpful if these inverters would tell you what the AC fault is instead of just saying "AC Voltage Fault". Is it too low, too high, frequency, line-neutral, what??? You can check the internal logs, and all you get is the same blunt message.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year

    The voltage and hertz are UL-1741 defined, basically below 217 or above 264 will cause a voltage fault or it can be line to neutral imbalance , same above values cut in half. On Frequency, its +- 0.5hz from 60hz

    GT/SG view will show all these parameters in real-time, ( including the reconnect timer ) so even if the GT won't come online, you will know exactly what the inverter is measuring for values

    The UL values by the way are measure in cycles, so if you have dirty power, a DVM might report a good value, but the GT is looking every 60 hz cycle, and by UL requires anything off for more than 2, 60hz cycle and the unit must fault for 5 minutes.

    There are much more involved direct reporting/configuring tool using the Xantrex supplied program ( GT-Config ) that can connect to the "B" processor, and show all the UL-1741 parameters .. there are something close to 30 values monitored by the inverter, Its not something your average home-owner would have access to but a dealer can get this from Xantrex
  • aj164aj164 Solar Expert Posts: 109 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year
    There are much more involved direct reporting/configuring tool using the Xantrex supplied program ( GT-Config ) that can connect to the "B" processor, and show all the UL-1741 parameters .. there are something close to 30 values monitored by the inverter, Its not something your average home-owner would have access to but a dealer can get this from Xantrex

    I have an XW-Config tool with USB<>XANBUS hardware. Is the GT Xanbus the same as the XW Xanbus? All I would need is the GT-Config software, then.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year

    The GT's have limited Xanbus features, Not sure if Xantrex ever released firmware for the GT's to be on the same network with XW's.

    GT-Config is a serial only program, it physically connects to the "B" processor when you push in the switch ( under the front panel ), which toggles the DB9 port , the "B" has access no to Xanbus
  • aj164aj164 Solar Expert Posts: 109 ✭✭✭
    Re: Fried 2nd Xantrex GT in < 1 year

    The inverter is bad. A replacement is on the way. There is most likely a cracked capacitor on the power board (or whatever the board is called). The previous inverter had this problem. I think I understood the tech to say that repeated grid disconnects under full power will exacerbate the problem. The circuit board traces lift slightly, which can stress the tiny capacitor and cause it to crack.

    The replacement will be a new design that fixes this issue, and it will have the new Xantrex/Schneider disconnect box.

    We have several Xantrex GTs out there. This is the only house where we've seen this problem. There is probably something going on at this location that causes the (normally functioning) inverter to disconnect. I think we still need to put a logger on the system when we get the replacement.
  • BB.BB. Super Moderators, Administrators Posts: 28,994 admin
    Re: Fried 2nd Xantrex GT in < 1 year

    Thermal cycling of the inverter and a less than great design on the PCB with surface mount components can be a real killer (or other related problem)...

    There was one brand of 5 1/4 in disk drives back in the mid-1980's or so--I could put it into a thermal cycling chamber and run it 2-3 cycles per day from 40F to 120F (or whatever the exact numbers were) and in one to two weeks I could cause SMD and other soldered components failures just like clockwork.

    Also with Surface Mounted Devices, proper soldering/thermal profiles are critical at the factory.

    About the only thing you can do to help reduce the problem is to limit thermal cycling (i.e., a fan and or shade if the inverter is in a location that traps heat).

    Other than that, you usually have to count on the factory to resolve their problem(s)--And it sounds like they are are (eventually).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Fried 2nd Xantrex GT in < 1 year

    I have a similar problem - my system has 3 GT3.0's in a 9KW system and one of them intermitantly drops off-line. It just started do this last week. I don't see how it is an AC line fault if the other two inverters continue to run OK. I just called my installer and am waiting for his return call.

    As a side note -These units are 3 years old now. The origninal 3 inverters all failed at about the 30 day mark due to some manufacturing issues. Xantrex claimed the subcontractor that assembled the inverters used some materials with incompatible thermal expansion coefficients. As the control board burned itself in it also sheared the pins off of an IC causing abrupt and complete failure. They apparently had a complete production run of these things to deal with. My installer and Xantrex jumped right on the problem and I got 3 brand new units installed within about 2 weeks of the original phone calls.

    I work in the power IC business and can tell you that differenctial thermal expansion is a huge problem if not addressed correctly. Micro cracks and electronics do not coexist very well.

    MG
  • rlkrlk Registered Users Posts: 1
    I have a Xantrex GT 3.3N,  it worked fine for 10 years, then one day a horrible electrical smell in the shop and the inverter is AC Voltage Fault 3.6 v.  Is the inverter fried?
  • BB.BB. Super Moderators, Administrators Posts: 28,994 admin
    Probably... And may not be worth (or possible) to repair 10 years after date of manufacture. Not many companies keep supply chain/inventory for that old of product.

    Back then, you could have a 5 or 10 year warranty on that product... If under 10 years, you might check and see if repairs are covered.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    GT's are long out of production.

    Also prices have fallen 75%, you can find top name string units for $600 ( 4kw ) and for double that with secure power, giving limited power when the grid is down
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,415 ✭✭✭✭✭
    Whoa,  Long time Solar Guppy! Glad to see you are still out there. I did a search once because an engineer at Schneider/ Xantrex was asking about you. are you still in Florida?
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • BB.BB. Super Moderators, Administrators Posts: 28,994 admin
    Hi Solar Guppy--Long time no hear.

    Hope all is well with you and your family... Last I read, you were moving out of solar and into a different line of work/industry.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    All is well and now in higher education, still in Florida.

    https://web.spcollege.edu/instructors/id/cutler.henry/BIO/

    Aside from price declines, I don't see much difference in RE from a decade ago?
  • Dave AngeliniDave Angelini Solar Expert Posts: 4,415 ✭✭✭✭✭
    Cool !  I agree that not much has changed. The prices are lower and there is cloud monitoring/configuration without needing port forwarding and finally the mppt-80-600v. Both Outback and Schneider have very nice cloud systems Insight2 and Optics.

    I am going to look at my e-mails back from a couple guys at Xantrex. One was asking about you. It was either Jeff Fieldhouse or Jeff Everett. Ring bells? They both have moved on to their own companies from Schneider/xantrex.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • Solar GuppySolar Guppy Solar Expert Posts: 1,962 ✭✭✭
    Both are connections on LinkedIn and I have keep in touch with them. Shame to see Schneider shut down Burnaby, and that there is little competition to match the XW system features, 14 year on ( not counting the China stuff on Alibaba ). Even as low cost as solar is, it is not an option where I live now due to shading :o


  • Dave AngeliniDave Angelini Solar Expert Posts: 4,415 ✭✭✭✭✭
    Hmm must have been somebody else. Did you know Dhaval Shaw? Maybe it was he who asked about you. The memory get fuzzy.

    Burnaby shut down their large commercial inverters but most of the guys I have worked with in the last 5 years are still there on XW+ and Xw pro are alive and doing well. Some very nice 75KW  xw microgrid  systems and clusters of 3 phase xw's are doing well.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • mike95490mike95490 Solar Expert Posts: 8,234 ✭✭✭✭✭
    All is well and now in higher education, still in Florida.
    Good to hear from you, your website closed, worried you'd cashed in your chips
    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 ,

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