RV system disconnect

I have 2 85w PV panels controlled by a low end thunderbolt magnum 35a controller mounted on a 5th wheel trailer. I have been told I need to disconnect the panels when I am hooked to city power. When I do this, my controller issues an audible alarm until the sun goes down. Is it necessary to disconnect the panels from the batteries.

Comments

  • BB.BB. Super Moderators, Administrators Posts: 30,640 admin
    Re: RV system disconnect

    Nope---You should leave the solar charge controller connected the batteries all the time (unless you have charging/voltage setpoint problems with the controller(s) and are over charging the batteries).

    Usually, the disconnect is on the AC side--Not on the DC side.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: RV system disconnect

    Welcome to the forum.

    No, it is not ordinarily necessary to disconnect the panels from the batteries when another charging source such as 'shore power' is connected.

    Let's be sure about this alarm thing: it sounds if you disconnect the batteries from the controller or it sounds if both are connected at the same time?

    In the case of the former it is probably alerting you to their being 'no battery' while at the same time the PV is still active. As a rule you disconnect PV first, then battery and reconnect in the reverse order.

    In the case of the latter the alarm may be indicating that the other charge source is pushing the battery above what it deems the maximum limit - over Voltage alarm.
  • Mustang65Mustang65 Solar Expert Posts: 42 ✭✭
    Re: RV system disconnect

    The question I have is "Why do you have to disconnect your panels when connected to shore power"? Who informed you that you need to disconnect them?
    I have an RV with solar and it is always connected. There is no link to shore power, only through the RV's battery controller, and that has no impact on shore power 120VAC. In my case I rewired that so that I can ALWAYS leave the RV's battery controller off.
    Don

    2013 Jayco Eagle 284BHS
    250Watt Grape Solar Panel, MorningStar MPPT 60 Charge Controller
    2 Trojan T145 Batteries (AH @ 20 HR Rate 260)
    1500 Watt Ramsond PSI,
    2 - AirSight Wireless IP Cameras (used as rear view cameras)
    EnGenius WI-FI extender, D-Link wireless modem (n)
    MagicJack Internet Phone
    2012 Ford F150XLT, EcoBoost w/3.73
    157" Wheel base, HD Towing Package
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: RV system disconnect
    Mustang65 wrote: »
    The question I have is "Why do you have to disconnect your panels when connected to shore power"? Who informed you that you need to disconnect them?

    You don't need to. Whoever told him to was misinformed.
  • Chuck46Chuck46 Solar Expert Posts: 95
    Re: RV system disconnect

    It may be because his converter is still hooked up and someone mistakely thought two charge sources were bad. actually those converters dont do a real good job at charging so haveing the solar charge all the time isnt bad. At least in my opinion:D
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