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Bobbo's avatar
Bobbo
Explorer II
Aug 22, 2021

Wondering if dealer did any damage.

In 2017 when we bought our brand new Airstream TT, we had the dealer add the airstream 90 watt solar package. He did so, and we have been using it for the last 4 years. I am considering adding more solar panels to the roof, and the OEM PWM controller needs to be upgraded. I bought a Victron SmartSolar 100/30 controller to use. When I opened up the compartment, I found what I am sure is a mistake. I think the dealer mis-wired the OEM controller.

It is a Sun Explorer (not the Sun Explorer II or III). It has 3 wires (plus the ethernet cable to the display panel). The red (hot) wire is connected to the battery positive, as it should be. The black (ground) wire is connected to the battery negative, as it should be. The yellow (PV hot) wire is connected to the PV hot wire, as it should be. However, the PV green (ground) wire that should be connected to the battery negative is, instead, also hooked to the battery positive.

Of course, I am going to wire the new controller properly, but I am wondering if the solar panel has been damaged.

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  • CA_Traveler's avatar
    CA_Traveler
    Explorer III
    Aug 22, 2021
    The PV + wire connects to the controller PV + terminal. The PV - wire connects to the - battery terminal, The small controller black wire is for the electronics only and not used for the - charging circuit.

    The PV green wire could be a PV frame ground or something else. Veryify that it's actually charging with a ammeter and there is a - negative PV to battery post wire.
  • Lwiddis's avatar
    Lwiddis
    Explorer II
    Aug 22, 2021
    If your 90 watt solar panel has been regularly filling your batteries, additional solar watts won’t do much. This would also indicate correct wiring. If you are adding battery amp hours then one solar watt for every battery amp hour is a good place to start.
  • BFL13's avatar
    BFL13
    Explorer II
    Aug 22, 2021
    There should be a pos and neg terminal for the two array wires as the controller's input. Should be a pos and neg (not "ground|) terminal for the output wires from controller to battery (pos wire with a fuse near battery)

    There might be a chassis ground wire normally not used with an Rv (stick house idea where they also ground the panels) Some controllers are "positive ground" instead of negative ground, which might be what you are looking at, don't know. In an RV where the chassis ground is not used, it doesn't matter which way the controller is--it only affects which path in the controller is switched (Mr Wiz has explained that)

    If nothing bad happened in the last four years, no worries at this stage.

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