Announcement

Collapse
No announcement yet.

Solar charge controller shows 0 volts

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Solar charge controller shows 0 volts

    I am running a 96 volt off grid system. I have just finished wiring the battery bank in series for 96 volts with 2 parallel strings. I connected the solar charge controllers to the battery banks positive and negative ends on opposite side. I have two MPPT solar charge controllers rated for 80 amps each, but I am only going to connect around 3500 watts of solar to each charge controller. I connected my first 4 panel PV array which is in series for a voltage of 163 volts and each panel is 300 watts.

    The problem I am having is when I turn on the breaker in the solar pv combiner box which then goes to the MPPT charge controller. The charge controller reads 0 volts. However, when I test with my multimeter the positive and negative ends from PV combiner box to solar charge controller it reads 163 volts. When I turn off the breaker in the PV combiner box the voltage on the solar charge controller reads 8 volts. I have no idea why it shows 0 and why it won't charge. Maybe I don't have the settings correct in the charge controller. Maybe the charge/float voltage needs to be higher?

    Attached are photos to show you what I am talking about. Any help or advice is appreciated.
    Attached Files

  • #2
    What manufacture and model number is the Charge Controller?

    First thing I notice is it looks like your PV voltage is too high and thus why I ask what controller you have. With 163 volts is exceeding a 150 Voc maximum input voltage limit. There are some Controllers out there that can go as high as 600 volts which you should be using with 96 volt battery.

    Next thing I notice is I see your system set up for Sealed Lead Acid batteries for 12 volts.

    Best guess is from looking at the pictures you have your panels improperly wired and the controller is not set up correctly. 300 watt panels suggest you have 72 cell panels, and if the controller is in fact a 150 Voc input limit controller, you cannot run 4 panels in series. 3 in series would be the limit. A system this size demands a 600 volt controller. With a 600 volt controller you would wire all the panels in series and would not need a combiner or any breakers on the PV panels.

    With an 80 amp controller operating into a 96 volt battery only requires 1 controller with up to 8000 watt input. Why do you have two? Anyway to get you going you need to get one string of panels working using just 3 panels in series first, then add strings one at a time. You have both wiring and configuration issues.

    Make sure the batteries are connected and wired correctly. Makes not difference is the panels are connected or not, you should read 96 volts at the output of the controller if the batteries are wired correctly and connected. As soon as the batteries are connected, the Controller should come to life so you can configure it properly for a 96 volt battery. Once you have that set up, tackle the panels.

    Good Luck
    Last edited by Sunking; 12-27-2017, 11:40 AM.
    MSEE, PE

    Comment


    • #3
      Originally posted by Sunking View Post
      What manufacture and model number is the Charge Controller?

      First thing I notice is it looks like your PV voltage is too high and thus why I ask what controller you have. With 163 volts is exceeding a 150 Voc maximum input voltage limit. There are some Controllers out there that can go as high as 600 volts which you should be using with 96 volt battery.

      Next thing I notice is I see your system set up for Sealed Lead Acid batteries for 12 volts.

      Best guess is from looking at the pictures you have your panels improperly wired and the controller is not set up correctly. 300 watt panels suggest you have 72 cell panels, and if the controller is in fact a 150 Voc input limit controller, you cannot run 4 panels in series. 3 in series would be the limit. A system this size demands a 600 volt controller. With a 600 volt controller you would wire all the panels in series and would not need a combiner or any breakers on the PV panels.

      With an 80 amp controller operating into a 96 volt battery only requires 1 controller with up to 8000 watt input. Why do you have two? Anyway to get you going you need to get one string of panels working using just 3 panels in series first, then add strings one at a time. You have both wiring and configuration issues.

      Make sure the batteries are connected and wired correctly. Makes not difference is the panels are connected or not, you should read 96 volts at the output of the controller if the batteries are wired correctly and connected. As soon as the batteries are connected, the Controller should come to life so you can configure it properly for a 96 volt battery. Once you have that set up, tackle the panels.

      Good Luck
      Attached is the model number its a Galaxy-B96-80AMP for the solar charge controller it has a max pv voltage of 430V. I have two solar charge controllers because I wanted to have a backup in case one breaks . I did not want to wire all the panel in series so I could have seperation among the arrays and so the voltage was not so high coming from the panels.

      I believe the batteries are wired correct because the charge controllers is reading the voltage correctly from the batteries at 104 volts. I think the issue may be that the battery settings need to have the charge volatage at 14.2 * (quantity of batteries) which in my case I have 8 12 volt batteries wired in series. and the same for the float voltage. However, Im not sure.
      Attached Files

      Comment


      • #4
        Whoops.
        What is the max Voc spec for your controller ? I suspect that is the problem, and you have over-voltaged the controller with nearly 200Voc (160V of panels @ Voc) I see the controller is in FAULT mode, not night time SLEEP mode.

        Did you follow proper Power-On sequence for MPPT controllers, battery first till it boots up, then apply PV voltage ?

        The next serious worrysome question I have is, why 96V batteries ? Not much 96V gear around, and it's way over the "normal safety limit" of 48V. Tough to get proper fuses and breakers for that voltage (Midnight Solar carries them, DC rated 150V & 300V breakers with specific polarity, and switch usage ratings)
        Powerfab top of pole PV mount (2) | 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

        Comment


        • #5
          Voltage of batteries??? Are you paralleling two 48-volt battery banks? In that case it is still 48-volts. Wondering if you have a typo..
          Last edited by citabria; 12-27-2017, 12:23 PM.

          Comment


          • #6
            Originally posted by citabria View Post
            Voltage of batteries??? Are you paralleling two 48-volt battery banks? In that case it is still 48-volts. Wondering if you have a typo..
            No I have a total of 16 12 volt batteries. 8 are connected in series for 96 volts and then then parallel. Yes, it is an unusual setup the voltage of the solar charge controller can handle up to 430V

            Comment


            • #7
              If anybody else has a similar issue I figured out what was mine. I had the polarity reversed on the output from the PV combiner box circuit breaker to the solar charge controller.

              Comment


              • #8
                Originally posted by crustbottle View Post

                Attached is the model number its a Galaxy-B96-80AMP for the solar charge controller it has a max pv voltage of 430V. I have two solar charge controllers because I wanted to have a backup in case one breaks . I did not want to wire all the panel in series so I could have seperation among the arrays and so the voltage was not so high coming from the panels. .
                The whole point of using MPPT controllers is so you can run much higher voltages on the panels using grid tied panels. High Voltage = High Efficiency. Not only that but it saves a ton of money like using much smaller wire and eliminating fuses, combiners, and breakers. You can use two controllers if you want, but configure the panels to run as many in series as the controller allows.

                Why do you think utilities run high voltage up to 1,000,000 volts?
                Why do you think Grid Tied systems run high voltages up to 1000 volts?
                Why do you think your controller was made to operate up 430 Voc input?

                So why are you running such low voltage on the panels? You are throwing your money away and not taking advantage of what your equipment was made to do. I told you what was wrong and you found it. Listen to me now.
                Last edited by Sunking; 12-28-2017, 11:10 AM.
                MSEE, PE

                Comment

                Working...
                X