Xantrex MPPT 60 charger controllers not working

Butcher
Butcher Registered Users Posts: 1
in Advanced Solar Electric Technical Forum #1
Hello all,
I'm new to the site forums, been a reader for a while now, but never posted before. I am hoping you guys can shed some light on my problem.

I have a new system that I just installed with my father-in-law. We are new to this and this is our first system we've ever done.
I have a XW system with a 4548 inverter and two MPPT charger controllers. Each charge controller is hooked up to Helios 3-250watt panels in a string with nine panels hooked to each controller. There is also 12 AGM batteries in the system.

We have 36 volts DC at the distribution panel from the panels and the charger controllers recognize that, as well as 48 volts DC from the batteries also recognized by the controllers.

The problem is the chargers aren't charging. They both say "Low light". When scrolling, the menus they also say "charger: off" Aux:off" I have done the commissioning steps through the CPS that's hooked through the network to the system.
The troubleshooting in the manual for "low light" under all conditions says we're on reverse polarity, but we've rechecked that several times and I don't think that's our problem, unless we're missing something.

Any help would greatly be appreciated, thanks.
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Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,638 admin
    #2
    Re: Xantrex MPPT 60 charger controllers not working

    Welcome to the forum Butcher!

    What is the Vmp-array???? If I understand you correctly, you have Vmp-array reported at 36 VDC and Vbatt at 48 volts.

    If that is true, then what sounds like is happening is your panels are all in parallel (what is their Vmp/Imp, and how do you have the array wired in series/parallel)?

    Basically, if you have the XW 150 VDC / 60 amp MPPT charge controller, you need Vmp-array (using panel specifications) in the range of 72 to ~100 VDC Vmp-array).

    There are almost no charge controllers that are designed to "boost" array voltage to the battery bank. The are all designed to drop voltage (MPPT actually "down converts" from high voltage/low current from the array to low voltage/high current for the battery bank).

    So, if my guess is correct, then the controller would see the too low Vmp-array as "insufficient sun".

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • NorthGuy
    NorthGuy Solar Expert Posts: 1,913 ✭✭
    #3
    Re: Xantrex MPPT 60 charger controllers not working

    Charge controller needs voltage at least few volts above battery voltage, so it won't charge 48V batteries from 36V.

    Why do you get 36V? Can you post the specs for the panels? You either wired them incorrectly or thare's someting wrong with them.
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  • ChrisOlson
    ChrisOlson Banned Posts: 1,807 ✭✭
    #4
    Re: Xantrex MPPT 60 charger controllers not working

    I talked to Butcher on the phone - he called me because he lives not too far from us near Duluth. He had the panels wired wrong. He'll get that straightened out, get them up to 92.4 Vmp, and it'll fire those MPPT60's right up.
    --
    Chris
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  • SkiDoo55
    SkiDoo55 Solar Expert Posts: 414 ✭✭✭
    #5
    Re: Xantrex MPPT 60 charger controllers not working

    Looked up string sizer for controller and panels should have Voc of 90+ to 126 VDC + coming from that configuration depending on temp
    GT3.8 w/4600W Trina 230W, TX5000 w/5000W ET-250W, XW4024 w/1500W ET-250W, 4 L16, 5500W Gen. (never had to use) Yet!!
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