Inverter issue with video

cleanspeed
cleanspeed Registered Users Posts: 7 ✭✭
Hello all,

I’m a newb to the forum and to solar. About two years ago we purchased a place with a standalone solar installation, not connected to any grid. I don’t know any of the history, but it has been trouble free to date.

Now to the problem that brings me here looking for help – we had been gone for about two weeks and came back to no power. When I went to check on it I found the inverter making what sounded like relay cycling noises, all the lights randomly blinking and the cooling fan turning on and off. I’ve attached a link to a video below. The inverter is a Xantrex SW Plus 2548, manufactured 2005.

I opened up the inverter and don’t see any obvious problems (to the untrained eye). We have had lightning lately, but I don’t see any visible damage outside the shed or to any of the components.

Has anyone seen anything like this or have any idea where to start?

Thanks in advance for any help,

Jim

http://www.youtube.com/watch?v=yUmzCi-rzAM

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter issue with video

    Welcome to the forum Jim.

    I don't do videos due to bandwidth restrictions here, but ...

    Turn everything off. Disconnect the charge controller from the PV array and the batteries. Disconnect the inverter from the batteries. Check the batteries for Voltage and Specific Gravity (if they are flooded cells) to be sure there's enough power to run the inverter. You need to have good battery power or else everything else becomes meaningless.

    Next reconnect the charge controller and see how it functions. If it isn't doing the job of charging the batteries there may be a problem there.

    Finally, with known good DC for input and all AC loads off try and turn the inverter on again and see what happens.

    I'm not saying this will fix anything, it's just the standard procedure for eliminating the obvious problems.

    BTW, when you leave for an extended amount of time it's always best to shut down the inverter if possible. Batteries stand a better chance of being charged then, even if the charging system fails.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter issue with video

    Welcome to the forum Jim!

    Sorry it is when you are having problems. Wow--that almost sounds musical.

    Anyway, first things first. What is the voltage of your battery bank? If flooded cell, can you measure the temperature corrected specific gravity of each cell? Measure the voltage across each cell/battery block.

    My first guess is that your batteries are near dead or dead (below ~46 volts resting or possible 42 volts or less). This can kill batteries--So first thing to do is get the battery charging.

    Is the solar array+Charge Controller working?

    Do you have a generator + Backup battery charger (if the SW will not start)?

    What typically happens is the system (AC inverter and some loads like a refrigerator) are left turned on--And something happens. A streak of bad weather, a battery cell fails, cable connection fails, backup genset does not start or runs out of fuel, more loads left on than usual (well pump on and water leak), etc.... The loads exceed the ability of the solar array to keep up with the loads and the battery bank collapses.

    Next--Even a near by, but not direct strike can take out your inverters/electronics--And you will probably not see anything obviously wrong.

    So--Can you figure out the state of charge of your battery bank and get it back to >90% state of charge first (battery bank may be toast in any case from deep discharge). If failed cell (or battery), you may be able to replace the one cell/battery and get the bank running again.

    Good luck.
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • cleanspeed
    cleanspeed Registered Users Posts: 7 ✭✭
    Re: Inverter issue with video

    Thanks for the welcome and the suggestions. Funny Bill mentions it sounding like music. My wife said it sounds like techno, I will have to take her word for it.

    The battery bank is 8, 6V in series. At the battery bank with a VOM I'm getting 51.0V. The charge controller is reading 51.2V. I will do as has been suggested and isolate each component leading up to the inverter and see if I find any problems.

    We do not have an integrated generator backup.

    Jim
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter issue with video

    Do you know if that is 51.6 volts charging, discharging, or resting? What was the voltage at the DC input terminals to the SW Inverter when it was attempting to power up.

    Believe me--I do not have an artistic bone in my body--If I call it "music", it may be stretch.

    Batteries have a fairly wide voltage range--Depending on state of charge, temperature, and the direction/amount of current flow.

    Poster "leaf" has a really nice set of charts that compare battery voltage against different rates of discharging and charging (as well as resting voltage readings).
    leaf wrote: »
    Am trying to upload the charts I am using...

    Attachment not found.Attachment not found.

    attachment.php?attachmentid=3655

    attachment.php?attachmentid=3654

    I don't quite a agree with the resting voltage line (I think the voltage is a bit low)--But it shows how to estimate a battery's state of charge while operating.

    Note, where the charts "flatten out"--the room for error estimating state of charge is pretty high.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Re: Inverter issue with video
    BB. wrote: »
    Poster "leaf" has a really nice set of charts that compare battery voltage against different rates of discharging and charging (as well as resting voltage readings).

    It was very nice of "leaf" to upload those charts, but let's give credit where it is due: Those charts are from Home Power Magazine.
    There is a link to the whole Home Power article in the 'Working Thread for Solar Beginner":
    http://forum.solar-electric.com/showthread.php?p=132977#post132977

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: Inverter issue with video

    51 Volts on a 48 Volt system is about "ideal" resting Voltage, so the batteries should be able to start the inverter. So the next question is: with all AC loads off does the inverter start? And what Voltage do you read at the DC input of the inverter when it tries?
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter issue with video

    vtMaps,

    I have added your note on the original source so when I copy and paste the original post, they will be properly attributed.

    Thank you,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Inverter issue with video

    Since you did one, best do another one, same exact one. Nothing is safe from the Internet parrots.

    Copyright 1993

    http://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf