Announcement

Collapse
No announcement yet.

Trouble Shooting new RV Solar Installation - Possible ground issue

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

  • Trouble Shooting new RV Solar Installation - Possible ground issue

    New Member here - thanks for taking the time to review my issue. RV with new 100W panel, Wanderer 30a Controller - 15 amp in-line fuse on hot from PV to controller and 30 amp breaker on hot from controller to battery. After several days of trouble shooting and controller replacement by Renogy (customer service and tech support have been great), I still have this issue. When I isolate my 2 - 12 v batteries on RV, meaning I disconnect the positive and negative leads from the house battery leading to my RV electrical system, everything works great - so the Renogy system is fine. As soon as I connect my RV battery leads to the batteries with the solar system connected, the PV charge light on my controller goes out and the current and voltage across the controller connector goes to near zero - there is very small voltage and current in the milli-amp range. Disconnect the RV house battery leads leaving the PV/Controller connected to the house battery and boom - the system comes back to life. I have not begun to trouble shoot the RV house system yet but everything works just fine in the RV, all lights, etc. and when I plug in the RV to shore power the RV charges the batteries. SO - when RV house electrical leads are attached to the house battery with the new controller and PV also connected, it shuts down the flow of energy from the PV. Seems like the ground is lost when RV house system is also connected to the house battery system. Any ideas would be greatly appreciated. Regards, Mark B.
    Last edited by mablamb; 10-27-2017, 01:31 PM.

  • #2
    OK just a wild arse guess, but I got a hunch. Did you run both Positive and Negative, or are you using Chassis Frame Ground as the negative conductor?

    If you did that, then that is your problem. Bottom line is you might have a Ground Issue, and that issue is you cannot use Ground as a circuit conductor. You need to run both polarities.

    Next time use larger damn Font, or I will sue you for age discrimination.
    Last edited by Sunking; 10-26-2017, 11:23 PM.
    MSEE, PE

    Comment


    • #3
      Originally posted by mablamb View Post
      New Member here - thanks for taking the time to review my issue. RV Trailer with new 100W panel, Wanderer 30a Controller - 15 a in-line fuse on hot from PV and 30 A breaker on hot to battery. After several days of trouble shooting and controller replacement by Renogy (customer service and tech support have been great), I still have this issue. When I isolate my 2 - 12 v batteries on RV, meaning I disconnect the positive and negative leads leading to my RV electrical system, everything works great - so the Renogy system is fine. As soon as I connect my RV battery leads to the batteries with the solar system connected, the PV charge light on my controller goes out and the current and voltage across the controller connector goes to near zero - there is very small voltage and current in the milli-amp range. Disconnect the trailer battery leads and boom - the system comes back to life. I have not begun to trouble shoot the RV system yet but everything works just fine in the RV, all lights, etc. and when I plug in the RV to shore power RV charges the batteries. SO - when trailer electrical leads are attached to the battery with the new controller and PV, it shuts down the flow of energy from the PV. Seems like the ground is lost when trailer is hooked onto the battery system. Any ideas would be greatly appreciated. Regards, Mark B.
      I doubt that the "ground is lost" when you connect the two batteries together, but it may be grounding issue.

      Sometimes you say "RV", sometimes "RV Trailer", sometimes"Trailer" - very inconsistent and very confusing.
      I am going to assume that all three words refer to just one vehicle an RV Trailer.

      So, initially you had an RV Trailer with a RV House Battery, and everything worked OK.

      Then you added a 100 Watt PV Panel, a Renogy Charge Controller and a separate PV Battery.
      Both systems work perfectly, only when the two battery systems are isolated.

      When you parallel connect the RV House Battery and the PV Battery
      the voltage that is output by the PV Panel goes to 0 Volts,
      measured at the input terminals of the Renogy Charge Controller.

      It sounds like the PV Panel is Positive Grounded and the RV House Battery is Negative Grounded.
      So when you parallel the two system the Solar Panel is shorted to zero volts.

      Verify that the PV Panel is NOT connected to ground, either on purpose or by accident (cut insulation in a through hole, clamp, screw, etc).

      Did you do any grounding on the PV Panel, Charge Controller or PV Battery?

      What is the voltage of the RV House Battery?
      What is the voltage of the PV Battery?

      Comment


      • #4
        OK - Sorry, I too am old guy - new to this and did not know I could change font size - I do now. Sorry for inconsistent use of RV/Trailer but your assumption is nearly correct. I only have 2-12 volt RV House Batteries and no PV battery. The RV House battery system all works fine. When I connect the positive and negative leads that run directly from the PV Controller to the house batteries, the PV and controller does not work. If I remove the leads that power the RV from the house batteries but leave the PV pos and neg leads attached, then the system is a stand alone PV/Controller/Battery and it works fine. The voltage on the house battery system is good at full charge, they run 12.8-13 dcv, The dcv and dca into and out of the controller run at spec from the PV - 19.5 dcv and 1.5-4.5 amps, current is dependent on sun of course and 100W PV is flat mounted on RV roof. From Charge Controller Manual - "The Wanderer is a negative ground controller. This ensures compatibility with any negative ground system, which is the standard and most conventional way of grounding. Any negative connection on the solar module, battery and load can be safely earth grounded as required." I do not know what that means but assume the grounding is provided through the RV House Battery System? I did not do any independent grounding of the system that I am aware of.

        Thank for your help, will begin trouble shooting RV house system this weekend and trace neg lead from battery through system and ID ground to chassis connection. Sincerely, Mark

        Comment


        • #5
          Originally posted by mablamb View Post
          [SIZE=14px]OK - Sorry, I too am old guy - new to this and did not know I could change font size - I do now. Sorry for inconsistent use of RV/Trailer but your assumption is nearly correct. I only have 2-12 volt RV House Batteries and no PV battery. The RV House battery system all works fine. When I connect the positive and negative leads that run directly from the PV Controller to the house batteries, the PV and controller does not work.
          House battery or PV battery, is just semantics and the same thing.

          Let me ask you this. You are connecting the battery to the controller first, before you connect the panels. You are doing that right? You cannot connect the panels to the controller followed by the batteries or else you get exactly what you have described. Batteries first, then panels.
          MSEE, PE

          Comment


          • #6
            Yes I have connected batteries first then controller.

            Comment


            • #7
              Sunking - thanks for response - perhaps I answered your question in my post above but if I understand your question, I did connect the negative wire from the PV to the Controller and the negative wire from the Controller to the House Battery bank.

              Comment


              • #8
                It sounds like the PV Panel is Positive Grounded and the RV House Battery is Negative Grounded.
                So when you parallel the two system the Solar Panel is shorted to zero volts.

                NEOH - How would I determine if my PV Panel is or is not Positive Grounded? Another bit of information that may or may not be helpful. With the PV/Controller/Battery connected and isolated from the House leads (which are disconnected), and I test current across the two wire terminals on the front of the Controller, I get a small spark and it turns off the PV charge light - (like short circuit) and my meter reads the amperage. Remove the multi-meter and the PV light comes back on and all is normal. Does that mean anything?

                Comment


                • #9
                  Originally posted by mablamb View Post
                  [SIZE=16px]

                  NEOH - How would I determine if my PV Panel is or is not Positive Grounded?
                  Easy Peasy with either a Volt Meter or Ohm Meter.


                  Use your DMM and measure voltage between ground and positive of the panel Terminal in day light. 0 Volts = Grounded, Voc to Vmp = Not Grounded.
                  Use Your DMM on a Dark Panel and measure resistance between ground and panel positive. 0 or less than 1 Ohm = Grounded. Open Circuit = Not Grounded.

                  If it is grounded, as soon as you connect the panels, they are shorted out and will not work.You will need different panels. Ground is a nasty thing and can get you hurt or burnt. So far just dark.
                  Last edited by Sunking; 10-27-2017, 06:12 PM.
                  MSEE, PE

                  Comment


                  • #10
                    This is sure a head scratcher - checked ground (white wire) from battery to chassis and it is a good connection. Used jumper cables to check ground to chassis, with RV DC system disconnected, as soon as I hooked the jumper cable from battery negative to the chassis with just the solar panel positive and negative connected to the batteries, the PV system goes dead. Connecting the batteries to chassis ground is what shuts down the PV system. Checked positive and negative directly from the PV in direct sun and it shows 4.5 amps dc and 20.5 volts dc. Checked the resistance on a dark panel and it showed about 4 ohms but not sure I am checking that correctly. On multi-meter, Rx1= 4ohms. Just do not know where to go from here.

                    Comment


                    • #11
                      It basically means you have the DC+ from the PV panel shorted to chassis somewhere. I would uninstall the panel, get it to where the wiring is all visible and intact, and see if you get a better result.
                      CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

                      Comment


                      • #12
                        Or perhaps unplug the panel, pull the PV+ wire from the controller, and measure ohms from that wire to chassis ground.

                        Comment


                        • #13
                          If I may have a hot wire shorted to chassis on the RV. Would that produce same result. I saw 12.5 volts on chassis when testing from neg battery terminal to chassis with PV disconnected and and RV pos and neg connected to house batteries. All dc fuses good and all circuits working on RV. Could it be shorted to chassis but still have all systems working on RV?

                          Comment


                          • #14
                            If there are no DC- connections to chassis, then yes, you could have DC+ shorted to chassis and all systems would be working. That is how a "positive ground" system would be wired.
                            CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

                            Comment


                            • #15
                              Originally posted by mablamb View Post
                              This is sure a head scratcher - checked ground (white wire) from battery to chassis and it is a good connection. Used jumper cables to check ground to chassis, with RV DC system disconnected, as soon as I hooked the jumper cable from battery negative to the chassis with just the solar panel positive and negative connected to the batteries, the PV system goes dead. Connecting the batteries to chassis ground is what shuts down the PV system. Checked positive and negative directly from the PV in direct sun and it shows 4.5 amps dc and 20.5 volts dc. Checked the resistance on a dark panel and it showed about 4 ohms but not sure I am checking that correctly. On multi-meter, Rx1= 4ohms. Just do not know where to go from here.
                              To the store and buy new panels. You have positive ground panels, and they cannot be used. No mystery at all, you bought the wrong panels. Replace them.

                              MSEE, PE

                              Comment

                              Working...
                              X