Diagnosis of Failed Charge Controller, or ???

tr0y
tr0y Solar Expert Posts: 99 ✭✭✭
in Off Grid Solar & Battery Systems #1
I am trying to figure out if my new out of the box Xantrex C35 Charge Controller has failed out of the box.

RV Mounted System overview:

500 watts of 12v 4 panels, 2 banks ( 17.4 voc I think ) showing 19.63v on digital volt meter
Small Combiner Box showing same voltage as panels
14 foot run of #4 wire to charge controller showing 19.62v at end of run
Xantrex C35 Charge Controller
2 405 AH AGM batteries wired for 12v standing voltage 12.96 after 12 hours of rest
Trace 1512 inverter charger

My problem is when I wire everything up, check it twice to make sure everything is correct, I get an error message from the C35 that says “load disconnected” or one slow orange blink, problem is load is clearly not disconnected. When this happens voltage at the load inputs in the C35 matches the battery voltage exactly, no fuses or breakers trip, no arc’s, just no PV power moving towards the battery bank. It looks like the power is moving backwards from the batteries towards the combiner box and array. Any thoughts?

The other strange thing I get is if I start the charger on the 1512 the C35 blinks rapidly stating that an “over current” situation is or has occurred, checking the voltage I get 13.56v that stays solid and doesn’t move over the 30 or so seconds I watched to make sure it was not doing strange things. At 12v 13.56 should not be an over current issue, am I wrong?

I have tried the reset, disconnected all power and wires from the C35 and reinstalled it with the same results, I think what I am doing is correct but can anyone see what I may be doing wrong, or would this be the sign of a failed charge controller?

Thanks
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Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #2
    Re: Diagnosis of Failed Charge Controller, or ???

    make sure you are using it in charge controller mode and not load control mode aka lvd as it sounds like that's what it's in. there's a jumper for this and should be on charge control. be sure all jumpers are placed properly for your requirements.
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #3
    Re: Diagnosis of Failed Charge Controller, or ???

    Hi Niel,

    I did go through all of the jumpers just to make sure, (I have had C40's in the past, before I went to the OB MX's in the house) so I checked and checked again to make sure it was in CC mode.

    The answer is yes per the printed board and the manual the jumpers are in the correct positions.

    Thank you though, I have been known to make that mistake.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: Diagnosis of Failed Charge Controller, or ???

    the manual lists only 2 other possibilities if it's already in charge control mode and that is the pv wires are reversed or the controller is overheating and could be caused by more current than the controller is rated for. these are fast blinks though and it states the slow is for lvd mode. maybe there is a fault in the pcb or maybe even a stray blob of solder.
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #5
    Re: Diagnosis of Failed Charge Controller, or ???

    That is what I was beginning to think, is I just got a bad one out of the box because it seems like it should work.

    Thanks
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #6
    Re: Diagnosis of Failed Charge Controller, or ???

    You don't having anything connected the "LOAD" port? (the low voltage disconnect DC Load Controller)...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #7
    Re: Diagnosis of Failed Charge Controller, or ???

    I am using the C35 in CC mode so yes the + input from the PV array is connected to the "PV + - Load +" DC terminal.

    From left to right the connections I have are : + battery cable, + PV input from combiner box, - battery cable, - PV input from combiner box.

    The LCD is now blinking orange in a string of five fast orange blinks, maybe that is a clue ?
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #8
    Re: Diagnosis of Failed Charge Controller, or ???

    This may be a wacky question but does anyone know if there is a possibility that the LED could be reversed and is showing orange when it should be showing green ?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #9
    Re: Diagnosis of Failed Charge Controller, or ???

    Beyond anything I can help with--Just checking the manual for the switch/pot settings like Niel asked about.

    Probably time to call Schneider/Xantrex on Monday.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #10
    Re: Diagnosis of Failed Charge Controller, or ???

    So I do think the 5 rapid blinks was / is the clue. After rereading the manual 5 rapid blinks equal the bulk stage of charging. So I went out to the trailer and reversed the LED and now I get 5 rapid green blinks to indicate bulk charging that would make sense.

    When I received the C35 the LED was loose in the box so I put it back in the ports on the main board, but there were no markings on either as to a proper install direction or polarity.

    So maybe it is working after all ?

    T
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #11
    Re: Diagnosis of Failed Charge Controller, or ???

    Sounds like you nailed it!

    There is no "Flat" on one side of the LED case and an associated flat on the silkscreen on the board?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #12
    Re: Diagnosis of Failed Charge Controller, or ???

    No just 2 tiny wires and 2 ports on the main board with no indication that there is a specific way to install the LED. The only markings state to remove the LED when installing the optional digital display. Go figure a note in the book would have been nice and saved some headache. Well this thread exists now and maybe someone down the road will find it useful.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #13
    Re: Diagnosis of Failed Charge Controller, or ???

    it would've been nice to know that up front that you had put the led back in there. in any case can you verify the current flowing to the batteries and what that amount of current is?
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  • tr0y
    tr0y Solar Expert Posts: 99 ✭✭✭
    #14
    Re: Diagnosis of Failed Charge Controller, or ???

    Ok that was it, backwards LCD status light, charge controller working fine, freezer is making ice and beer is getting cold. Listening to the stereo while I was working.

    Charge Controller status is "float" at 13.39v

    So no broken charge controller just a mis-installed monitor LED and what looked like low voltage from the panels was actually the charge controller working and charging the batteries.
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