Bulk Absorption Chg Finish Selltogrid

13

Comments

  • Solar GuppySolar Guppy Solar Expert Posts: 1,973 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Nope, you've killed the battery's you have by abusing them. You need 600ah of NEW battery's.

    You were warned not to run this system under capacity which you ignored, the cost is your battery bank.

    If you want to run a test, turn off both charge controllers , flip the AC1 breaker on the XW-6048, load it down and see how long it runs before you under voltage fault. You can use the SCP reported watts to give you an idea of the effective ah left in your battery bank. I'd hazard a guess less than 25% based on all that is going wrong
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    Nope, you've killed the battery's you have by abusing them. You need 600ah of NEW battery's.

    You were warned not to run this system under capacity which you ignored, the cost is your battery bank.

    If you want to run a test, turn off both charge controllers , flip the AC1 breaker on the XW-6048, load it down and see how long it runs before you under voltage fault. You can use the SCP reported watts to give you an idea of the effective ah left in your battery bank. I'd hazard a guess less than 25% based on all that is going wrong



    Well, I have previously run that test successfully and it did not prove a thing. Your simplistic assertions appear to ignore the complexities of the issue especially the ones of the time of day (usually before full daylight, but not always) and the one of the weather (sunny, foggy or rainy - no matter). Then there is the issue of what others in the neighborhood experience at the same times providing an indication that there is an influence from the utility. And then there is the issue of no fault warning from the inverter - what is it sensing that causes it to fail so miserably?

    More ironically, the system can perform flawlessly for weeks at a time - how does that fit into this equation?

    Are you sure you have read this entire thread - I mean that it could be a lot to assimilate if you just came on board?

    The reason I ask is that I came down on Xantrex on this issue on Friday, gave them the link to this thread to help them understand and now you show up here making the same blanket statements you have made previously in my other thread???

    I ask that because the TS staff knows you personally and it did cross my mind........

    I wouldn't wonder about this so much, but I never get any rational for the blanket statements you make, you just blatantly assert that I'm not following the plan, per se and that you have warned me before.

    Let me assure you that I have a very logical manner of approach and if this were a clear cut case with simple unknowns I would agree, but it simply is not clear nor is it open to a simplistic resolution.

    I'll let you know the results of the test, without a doubt.

    One last question, how would you like to reinvent your system based on the simplistic recommendations of someone and then come to find that it didn't fix the problem and that you spent thousands of dollars needlessly?

    Well that’s what I’m definitely going to avoid.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    so this morning at 5:30 with heavy fog, the inverter starts selling to the grid at 10-24 watts, obviously from the battery.......... Both charge controllers show “not charging” and it was very dark out. Is it possible that I have never noticed this before and the situation is normal?

    BTW, I did test the batteries and have all the empirical data and will post the results soon. The test was positive and the batteries tested near spec. Each of the batteries were within .03V of each other, throughout the test.
  • Joe_BJoe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    Nope, you've killed the battery's you have by abusing them. You need 600ah of NEW battery's.

    You were warned not to run this system under capacity which you ignored, the cost is your battery bank.

    If you want to run a test, turn off both charge controllers , flip the AC1 breaker on the XW-6048, load it down and see how long it runs before you under voltage fault. You can use the SCP reported watts to give you an idea of the effective ah left in your battery bank. I'd hazard a guess less than 25% based on all that is going wrong

    I think S.G. has pointed out a valid problem, here is a quote from the Schneider website:
    A battery bank is required for inverter operation. A minimum bank of 100 AH is required, but a 200 AH minimum (400 AH for the XW4024) is recommended if you need to power any loads over 1000W.

    Your bank is very marginal and in time, we all know that the bank capacity will drop.

    I cant say for sure that the failure you are describing in this thread is caused by a too small battery bank size but it is something to consider as being related. I can tell you that originally I had a 320 AH bank of FLA connected to mine and I quickly upped it to a 740 AH because the battery voltage was all over the place. By adding more battery, my system became much more stable.

    Joe
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Here are my battery load test results for a 3.5 hour test at a 26 amp load conducted on 7/26/11 – that load compares most closely to the 8 hour rate in the figures provided by the manufacturer below and therefore was used in the anticipated voltage drop calculations provided just below that. Please note that in the absence of a discharge curve from the manufacturer, a linear curve was assumed.

    Manufacturer specs on the PVX-2580L Solar Battery Bank:
    1 Hr. Rate=165 Ah or 165A per hour
    2 Hr. Rate= 209 Ah or 104.5A per hour
    4 Hr. Rate=214 Ah or 53.5A per hour
    8 Hr. Rate=236Ah or 29.5A per hour
    24 Hr. Rate=258Ah or 10.75A per hour=Battery rating

    I have been led believe that manufacturer’s battery ratings assume the function of the battery is suitable down to 10.5 volts. Since the test started at 12.65 volts (I purposely have the battery charge setting at this level which will skew this example a bit) and at the 8 Hour rate one can infer the loss per hour assumed by the manufacturer starting at a nominal level of 13.6 volts. 13.6-10.5=3.1 divided by 8=.3875V per hour drop. In the case of the load test the drop was .61V over a period of 3.5 hours.

    Assuming a somewhat higher 11.5V minimum function level the math is 13.6-11.5=2.1 divided by 8=.2625V per hour drop. Using this drop for 3.5 hours the drop may have been .919V compared to .61V actual. Based upon my 12.65V charge level choice for my bank, I am well aware that the math might be calculated somewhat differently by others.

    In any case, even though this kind of comparison is potentially fraught with differences of opinion, it seems reasonable to conclude the batteries in this system are functioning more or less normally. BTW, throughout the test, all the batteries’ individual voltage levels did not vary by more than .03V and all voltages dropped linearly and they all settled to 12.3V+- in a short time upon removing the load and before turning on the system on again. It doesn't seem like this is a “cooked” set of batteries.

    The inverter has been working flawlessly for the last two day, sans the earlier report this morning of selling with no harvest from the arrays.

    All is currently normal and has been since the completion of the battery load test two day ago. That obviously doesn’t mean much in view of how the system has mis-behaved off and on, but there could be something that occurred during the test that may now cause the Phantom Faults to become dormant issue.

    I have observed that the only time the phantom fault sequence normally appears on the SCP without some kind of a fault/warning is when the Grid has been disconnected or down, if you will. Under normal conditions, when the grid returns from an outage, the above is what happens and the inverter, at the very end, does a 6000W grid sell test and then continues to sell at the level above the sell voltage (watts harvested vs. overhead and charging requirements). But, in the case of the phantom fault, the inverter is immediately returning to Bulk, etc. in an infinite loop as though there was something wrong with the grid/connection, cycle after cycle (BTW, I have never trapped a fault with my meter when the phantom cycle was in progress). I have no documentation as what is being tested for, but it appears reasonable that continuity and the ability to push the grid is among those factors being tested. There are a significant number of points within the 6048 that could also be at fault in that regard, most being internally inaccessible and another being the grid disconnect breaker which was exercised during the process of the battery test and which now becomes a point of focus. There obviously were the other internal inverter contacts that were also exercised.

    This system rarely sees invert mode and of course, when the grid goes down by itself, that breaker is never exercised. I will keep that in mind and attempt to test for a failure when and if the next event occurs.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,973 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    pcguy2u wrote: »
    In any case, even though this kind of comparison is potentially fraught with differences of opinion, it seems reasonable to conclude the batteries in this system are functioning more or less normally..

    Refer to the attached graphs, the typical range is 12.6-11.5 for 100-0% SOC

    Also discharge is not linear ( in time , not voltage ). You need to run down to at a minimum 80% DOD or about 11.75V @25C.

    Best case, looks like your batteries are at about 60% of rated capacity, likely lower as the battery's voltage will tail off as the discharge continues.

    From what I can see, it supports your battery's are now likely half the rated capacity as a previously guessed using your own data
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    they may be a tad better than that sg as those are not the at rest voltages he probably measured. he needed to see what the voltage recovered to to get a better idea of the real voltage differential.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    As I suggested, everyone has an opinion about how this should be compared. For the record, the voltage readings in the above post were all taken during the test on the batteries individually along the series string and while they were under load and they were not open circuit readings.

    Also, the one reading of 12.3V that represents the at rest level of recovery after a few minutes, was taken without opening the large battery circuit breaker, but it was taken with the house load removed. This means that the nominal load from the inverter was factored into that reading. Of course, if I do it again, I'll do it differently.

    FWIW, I don't believe any of this is indicative of the underlying issue, whatever it turns out to be.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,973 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    pcguy2u wrote: »
    I don't believe any of this is indicative of the underlying issue, whatever it turns out to be.

    I see, well nothing else I can suggest.

    When you have discovered and corrected your issue please post back the proper solution.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    pcguy2u,
    sorry, but a start voltage of 13.6v will never be an under load start as that is open circuited. i was trying to locate more info on concorde's site for load testing and i didn't readily see it, but never make assumptions. even the 10.5v is an assumption and you should contact them to get the correct parameters the batteries get tested under. i do know they tried selling their own tester for big $ years back, but unless you come across many batteries it isn't worth the investment to the end user. they can tell you exactly what to look for and if it is an at rest voltage or not for the final determination as even in the charts by sg those are not under load, but are at rest open circuit readings. at rest may also need to be defined by them, but most of the time 3-4hrs of rest gets you pretty darn close.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    We need to give rise to the main question here - why is this problem so intermittent? If the batteries were the sole source of the problem, the problem wouldn't disappear for weeks/months at a time with the system working perfectly - batteries always get worse not better and when batteries are toast, they don't support anything.

    I'm not disagreeing that the manufacturer states one thing and I'm doing something else - I just don't find an absolute association and the system functions perfectly most of the time. As I write this the system has been functioning normally since 7/22/11 at 9:30AM - absolutely no repeat of the phantom fault cycle.

    At the moment I do find that this problem appears to have an association with attempts to sell to the grid that are failing time after time, and I need to understand what that is comprised of and why there is no message displayed. As I said previously, you may rest assured that the next time (given there is one) the phantom faults are occurring, I will test/exercise that breaker.

    At least that direction coincides with an intermittent problem, unlike a battery failure.

    Directing a technical question such as the what the phantom cycle consists of, to the TS staff at Xantrex, a question that they can't answer, causes you to then ask to be referred to someone who can answer that question, they then refuse - or they say they will have to get back to you and they never do.

    I can't help but wonder what motivates folks to exclude the obvious. In this case, the obvious is that the problem is not continually degrading, it is intermittent and last time I checked, intermittent usually means a bad connection somewhere. I've never seen a battery with an intermittent failure - they just slowly get less useful or they suddenly die totally.
  • BB.BB. Super Moderators, Administrators Posts: 32,005 admin
    Re: Bulk Absorption Chg Finish Selltogrid

    From my point of view (not speaking for anyone else)--The XW is taking power for the grid/local power and to run its own electronics from the battery bank.

    Many times, less than ideal power for computers ends up with glitches, corrupted memory, and other random acts.

    Is the the case with an XW and your battery? I really do not have a clue. But given that the XW appears to have large draws with little sun (self check?) and many MPPT controllers occasionally output maximum power from the array to the battery bank as a data point for MPPT computations--Running a battery bank over C/2.5 (exceeding 40% of battery surge capacity) runs the possibility of taking the battery out of its "regulation zone".

    Even though there are many "regulators" in a Hybrid power system (AC charge controller, GT shunt controller, Solar MPPT charge controllers, etc.)--The battery bank is really the only instantaneous capable voltage regulator in the system. The others will only respond over seconds, or longer, in time. And running more than 40% surge is capable of taking many "flooded cell" batteries out of "regulation" (~42 to 60 VDC for a 48 volt bank)--And during charging, >40% surges are capable of taking AGM batteries out of "regulation" too.

    Anyway--that is how I would explain the concerns.

    If you have a fast DVM set to capture battery bank voltage excursions outside of ~46-60 vdc during normal operation -- and don't see any -- then you are probably right and the batteries are not a factor in your system issues.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Hi Bill, thanks for meaningful response, I agree.

    Over time, this problem has occurred with all kinds of weather conditions and there really isn't any pattern re available solar power.

    Also, keep in mind that I have never exercised that grid disconnect breaker since January of 2009 and the first time was this week.

    Also, the F49 (inverter) and sometimes associated F70 (charge controllers) have not appeared for about a year now.

    BTW, I promise to be absolutely forthcoming about any resolution to this problem, no matter how incorrect my position may or may not be.
  • BB.BB. Super Moderators, Administrators Posts: 32,005 admin
    Re: Bulk Absorption Chg Finish Selltogrid

    pcguy,

    It is really because we care--It is sometimes very difficult and frustrating, for everyone, to debug by Internet...

    -Bill "but we still try" B. :-)
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Here's an update to this situation that attempts to explain my rationale for pushing on the breaker as the source of the problem. It is more or less a thank you to my electrical engineer friend who has worked with me in the background. He is not on this forum.

    If you have any comments that may shed light on this explaination or have a question about what I may not have been clear on, please post away.

    Many thanks,
    Nick


    Hi Bob, thanks for all your effort here. Just an update on this situation – here’s an entry in my spreadsheet/log on this problem that I made as a note to myself:

    During the last week with the tests I conducted, the grid disconnect breaker for the inverter has been exercised a number of times. Have not previously exercised the grid disconnect breaker, at least not for the last year or so. An intermittent break in this contact could answer all the problems experienced at 8:03AM, ie F25, F29, F30, F49, etc. It doesn't explain the issue of what is otherwise happening at 8:03AM - while that appears to be the catalyst, it would not appear to continue to cause any issue if the breaker is the underlying cause. When this problem occurs again, as a cyclic issue, I will exercise the breaker to see if that breaks the cycle – normally the cycle can go on for hours.

    The rationale for the assumption is as follows: On Monday morning while beginning the isolation tests you described previously, I went to the main disconnect panel 300’ from the house to turn off the grid. I did so with the 200AMP breaker and went back to the inverter and found a fault called “AC Over Voltage”. I had already realized that I could not conduct my test because I no longer had any place to test from without breaking the PG&E seal. So I had turned the breaker back on and the inverter had already began the series of reestablishing it’s grid connection, which happened successfully as it would normally. Almost all pretty normal, except the AC Over Voltage issue that was sensed by the inverter – clearly there wasn’t an over voltage problem with a disconnect. That got me to thinking that any kind of interruption in the line could cause the a similar incorrect sensing of a problem (whether it be any of the faults I listed above) and the inverter would be reacting to that interrupt by starting the grid connection process over again. If at the end of that cycle where the inverter normally uses the batteries to momentarily push 6000 watts onto the grid as a final test and at that point, the breaker continues to fail/not provide the proper continuity, the cycle would start over again, especially if the grid magically reappears, because it never really was absent.

    I have to think that if the problem was with the 200amp main breaker, I would have had many problems with power in the house over the years and that simply isn’t the case. So it leaves only the inverter breaker and the inverter internals, of which both have been exercised 4+ times this week. However, the internals have been exercised regularly over the years, every time the power goes out and the unit starts to invert. By a process of elimination this leaves only the breaker as the likely cause.

    I will give you the final analysis, however only time will tell. In the meantime, the PG&E issue deepens because we don’t know what is really happening at 8:03AM. All I know is that nothing I have on a timer is set for 8:03AM.


    Many thanks again,
    Nick
  • solar_davesolar_dave Solar Expert Posts: 2,382 ✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    hmmm some how that sounds familiar.

    My PVP inverters faulted a while back, I started trying to track it down. Checked the DC inputs voltage, the breaker in the main panel, the connections for tightness, cycled the breakers in the combiner box, nothing! Both inverters continued to fault but with different error codes and messages each time I cycled them. I was stumped.

    Then I took the AC combiner box cover off and tested the line voltage there, should have been 240v line to line and 120/120 line to neutral. Voila!!! one leg of the 240 was dead between the combiner and the main panel. Only thing in the line was an AC disconnect switch with a utility lock and a PV meter with a utility seal. Then I noticed the main smart meter had been changed/pulled and resealed!

    Here is the sequence of event I suspect, power company came out to do the meter change out or check, and threw the AC PV disconnect switch and the main breakers, screwed with the meter, flipped the mains back on and softly engaged AC disconnect, but the AC disconnect didn't get both legs hot. A power off on that disconnect and a rapid hard engagement of the switch cured the issue.

    Perhaps one leg of your breaker was at fault.
  • BB.BB. Super Moderators, Administrators Posts: 32,005 admin
    Re: Bulk Absorption Chg Finish Selltogrid

    A year ago, my electrician friend was telling me about Smart Meters (dozens?) that were cutting one of the hot legs into the homes. PG&E called for replacement--sometimes replaced twice (some/many/all smart meters can turn off power remotely to the home).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    solar dave,
    do you suppose that could be the problem at 8am as this so far would not explain the time factor on this no matter what theory is raised so far? hopefully when it is finally found out for sure it may shed a bit of light on why at that time.

    pcguy2u,
    i was not trying to blame your batteries in my last few posts, but i want you to be sure of what their status is is all and if you read my comment correctly i stated i felt your batteries are doing better than the 60% mentioned. even so, concorde considers them in need of replacement at 80% and you don't accurately know where you stand right now in relation to that. call or write them to be sure.
  • solar_davesolar_dave Solar Expert Posts: 2,382 ✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    niel wrote: »
    solar dave,
    do you suppose that could be the problem at 8am as this so far would not explain the time factor on this no matter what theory is raised so far? hopefully when it is finally found out for sure it may shed a bit of light on why at that time.

    Perhaps that is the time the solar gets kicking a bit and a poor connection in the breaker then fails. Perhaps not a 100% fault just high resistance. If it blips the grid line wouldn't the inverter detect it and fault? Could the breaker be arcing internally?
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    niel wrote: »
    solar dave,
    i was not trying to blame your batteries in my last few posts, but i want you to be sure of what their status is is all and if you read my comment correctly i stated i felt your batteries are doing better than the 60% mentioned. even so, concorde considers them in need of replacement at 80% and you don't accurately know where you stand right now in relation to that. call or write them to be sure.

    Hey Neil, thanks for that. That was how I interpreted them. Was out of town yesterday - new update and possible/real solution may be in hand. At least for the phantom fault.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    The issue does not appear to be the grid tie disconnect breaker. I ran a voltage cross check (Line 1 in to Load 2 out and vice versa) under load and it read perfectly.

    So I began to look at my other thread on this inverter and also reviewed that thread for the changes that were made as a result. Lo and behold, the AC Charger setting has somehow been reset to “ON” – I thought I had checked that along the way here, but....... The clue here is in my original post in this thread where I asked.

    “Could a setting in the system have changed inadvertently, or what is really going on here? Yesterday, when I noticed the problem at about 7:00AM, I reset (powered down) the system and initially there was no improvement, but it seemed that after the sun came up and while I wasn't looking, everything started working normally.”

    Another clue was in post #64 where I asked why the inverter was selling at night.

    Anyone ever see settings get lost?

    My guess is that the AC charger was adding voltage to the batteries at odd times to change the threshold above the sell level and at other times, caused a fatal embrace between two variables that caused attempts to sell but failed on some aspect of the associated test that no one has been able to fully explain. Clearly this is somehow related to the AC charger involvement. I do suspect that the “test” caused the battery voltage to fall below the “sell voltage” and the test then ended “Sell” and the AC charger then raised the voltage above the “sell voltage” again and the process started over again, every 5 minutes. All this is conjecture, but I will report when more info is available.

    Still don’t have any answer to the various Grid faults at 8:03AM occurring most frequently on weekday mornings – F25 yesterday at that time. At the moment, I can live with those.

    I did put my hands on a 100AMP load tester and I will take the system down and test the batteries individually. The test is suggested to be 10 seconds and with the load still on to read the meter for the battery condition. I believe the unit is rated for 1000 cold cranking AMPs which implies automotive, however the instruction imply that the test is benign, just can’t be sure if the results will be meaningful. Comments?
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    glad to hear you are making some progress here. maybe those other faults will disappear, hopefully.

    did you find where concorde is specifying the load test parameters as i couldn't find it? please post the link as i too have concordes. in any case keep us updated as to what you find.
  • Joe_BJoe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    If you are in sell mode and the battery voltage drops to 1 volt above the LBCO, the charger will automatically begin a cycle. See figure 3-7 in the manual.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    I did see the LBCO actions which could add to the explanation, but I have never observed 44V, especially for 10 seconds.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    pcguy2u wrote: »
    I did see the LBCO actions which could add to the explanation, but I have never observed 44V, especially for 10 seconds.

    I should have added that I have observed the voltage drop at the time all this is going on and it never really dropped much, like less than a volt from the nominal level. Of course all that is happening very quickly and it would be easy to miss something.
  • Joe_BJoe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Something just occured to me, you are getting a charge finish. Assuming that the AC charger is disabled, your SCC's should never charge finish. You should have them set to 3 stage mode so they go into float. Forgive me if I am mistaken but I did not go back and re read the thread so I cant remember if you had stated the SCC charge mode.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Originally way back in the beginning, the charge mode was set to 2-stage and not 3 - I don't recall why when I think about it - the contractor had his reasons is the best I can come up with.

    Yesterday, I bothered to check the settings again and found the mode was 3 (ie, with float) and I changed it back to 2-stage.

    Of course, when I was getting a ChgFinish, the setting were AC charger=enabled and with 3-Stage set.

    This is a bit confusing to me as I don't pretend to fully understand all the implications.

    The system has been totally normal since Friday morning.

    Late Friday, I finally received a call from Xantrex/Schneider TS and they are sending me the config tool/dongle and the the latest firmware. They also offered to replace the inverter at my option. In view of the lost options settings, and the fact that this unit arrived here, way back when, with Fault warnings (with dates from before I purchased it) in the log (they never answered my question as to whether the unit was new or not), I might take them up on that.

    Thanks for the help to date.

    Nick
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    Was reading on Page 4-7 of the XW6048 operations guide:

    Problem:
    In a grid-interactive mode, the unit is experiencing excessive anti-islanding faults. The utility grid is not dropping out, yet the unit is disconnecting from the grid.

    Possible causes:
    The unit has two sets of AC limits: adjustable AC qualification limits (as set on the AC Settings menu), and nonadjustable anti-islanding limits which are required to have a 5-minute reconnect delay before returning to grid-interactive mode (Sell Mode or Grid Support).

    While in Sell Mode and in Grid Support, these two sets of limits are both active. Whichever limits are set to more restrictive values (the narrower voltage and frequency windows) will trip first when the utility grid varies from normal values.

    If the AC qualification limits are set outside the fast anti-islanding limits (see F27, F30, F37 and F40), the unit will experience less frequent disconnects
    from the utility, but when it does disconnect there will be a 5-minute delay (minimum) before re-entering a grid-interactive mode. During this 5-minute delay, all other modes of operation will be available, assuming the grid re-enters the user-set frequency and voltage limits (see “AC Settings” on page 3–16).

    If the AC qualification limits are set inside the anti-islanding limits, then the unit will experience more frequent disconnects from the utility, but when it does disconnect there will not be a 5 minute delay before entering a grid-interactive mode, assuming the grid reenters the user-set frequency and voltage qualification limits.

    The impedance of the utility grid is too high for the power being sold to the grid. The utility grid impedance may be on the high end if the installation is too far from the utility sub station. If this is a possibility it says - Reduce the Max sell current (default of 27.0) until unit stops disconnecting.
    _____________________________________________________________________________________________________


    Our location is about 3 miles from the substation and at the end of two 12KV legs that come together at a remote switch and that can be switched to the other substation which is further away by many miles. We really have no way of telling which one is providing power.

    While it seems clear the has involvement in the F25 and other anti-islanding issues are related to the issue of proximity. I wonder if any of the above had some interaction on the F49 issue???? In any case, the fix for F49 was to lower the Sell Voltage not Current and to turn off the AC charger.
  • pcguy2upcguy2u Solar Expert Posts: 139 ✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid

    To be a bit more clear about the phantom faults, I have the feeling that the end of the sell sequence occurred because the 6000W surge test from the batteries caused the batteries to fall below the sell level.

    Hope that adds to the understanding and doesn't add confusion.

    System has been functioning normally.
  • Joe_BJoe_B Solar Expert Posts: 318 ✭✭✭✭✭✭
    Re: Bulk Absorption Chg Finish Selltogrid
    pcguy2u wrote: »
    To be a bit more clear about the phantom faults, I have the feeling that the end of the sell sequence occurred because the 6000W surge test from the batteries caused the batteries to fall below the sell level.

    Hope that adds to the understanding and doesn't add confusion.

    System has been functioning normally.

    Bingo, you have just determined that the battery bank is too small.
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