mystery wires

bill
bill Registered Users Posts: 4
in Solar Beginners Corner #1
I purchased a used Outback 3524 inverter from someone I have lost contact with. With the top cover removed, exposing the battery terminals, I found two black leads; one labeled DC+ and the other labeled DC-. The ends of these leads fit the battery terminals, and they are about 20 something AWG. This size wire isn't made to handle much current so they must be used for potential rather than power. My main concern is the path these two wires take from the A.C. side up thru the top of the unit (to connect to the battery posts) without accessory holes. If I tighten the screws on the plastic cover the cover bends where the leads go (center of cover) from bottom to top.
I need to know the purpose of these two wires and what route they should take. I suspect they provide the exact voltage of the batteries, i.e., not subject to I square R drops.
Thanks,
Bill
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Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: mystery wires

    What are they for? Who knows. Remove them.
    The only thing that connects to the battery terminals is the battery wires. Probably the previous owner had some monitoring equipment on it such as battery sense wires for an MS controller. This would be the wrong place for that, by the way: battery sense wires go on the battery.
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  • bill
    bill Registered Users Posts: 4
    #3
    Re: mystery wires

    These wires terminate on the battery posts!
    I won't be satisfied until I find out what and why.
    It is important to remember that these two wires originate inside the inverter.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: mystery wires
    bill wrote: »
    These wires terminate on the battery posts!
    I won't be satisfied until I find out what and why.
    It is important to remember that these two wires originate inside the inverter.

    There are no wires that come from 'inside' the inverter and go to the battery posts on a 3524. See pic. Sounds like someone has been messing with it.
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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #5
    Re: mystery wires

    With some charge controllers, not inverters, there are separate battery voltage test leads that let the CC set the battery terminal voltage to the desired value rather than just putting out the set voltage on the CC output terminals. What the equivalent function would do on an inverter escapes me. :)
    SMA SB 3000, old BP panels.
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #6
    Re: mystery wires

    Perhaps this unit has/had the tubro vent fan on it? Usually that is connected to he AUX terminal (under the plastic cover) but he may have hooked it directly to the battery for some reason?

    Reaching here.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #7
    Re: mystery wires

    I assume that this is an Inverter/Charger--So conceivably, it is possible that they have remote sense wires to accurately measure batter voltage--But I don't find any such connections in the (what I could find) installation manual:

    http://www.outbackpower.com/downloads/documents/fx_vfx_series/fxseries_installmanual.pdf

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #8
    Re: mystery wires
    BB. wrote: »
    I assume that this is an Inverter/Charger--So conceivably, it is possible that they have remote sense wires to accurately measure batter voltage--But I don't find any such connections in the (what I could find) installation manual:

    http://www.outbackpower.com/downloads/documents/fx_vfx_series/fxseries_installmanual.pdf

    -Bill

    No, they don't: I have the same inverter myself.
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  • Tulumtam
    Tulumtam Solar Expert Posts: 37 ✭✭
    #9
    Re: mystery wires

    I am guessing they are from the Flexware surge protector. I have installed a couple of these and they have ring terminals labeled DC+ and DC- which connect to the DC terminals of the inverter.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #10
    Re: mystery wires

    Here is the replacement surge suppressor board (based on Tulumtam's post above):

    http://www.outbackpower.com/downloads/documents/flexware_surge_protector/fw_sp_specsheet_english.pdf

    Attachment not found.

    https://www.myenergywarehouse.com/fw-sp-r.html

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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