Trimetric Question

ironbridgeironbridge Registered Users Posts: 9 ✭✭
in Solar Beginners Corner #1
RV system.  I installed a Trimetric 2030 with the sc 2030 charge controller and the 500 amp shunt.  I have two 135 watt Kyocera panels wired in parallel....but my question is when there is no dc load and charge the controller is off my Trimetric always shows a negative .1 or .2 reading.  I disconnected the dc fuses one at a time to see if a circuit was drawing current but it made no difference.  Thanks for any help.
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  • ironbridgeironbridge Registered Users Posts: 9 ✭✭
    #2
    I wanted to add...other than that the system seems to work fine.  Trimetric shows negative loads when I turn on dc devices and the panels charge the battery fine.
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  • PhotowhitPhotowhit Solar Expert Posts: 5,989 ✭✭✭✭✭
    #3
    It likely is the monitor it's self...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
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  • BB.BB. Super Moderators, Administrators Posts: 33,081 admin
    edited March 2017 #4
    The Trimetric is reading 1/10,000th of a volt or so (0.0001 volts or even 0.00001 volts). So, that small amount is within the accuracy of the meter.

    You may find a setting for the Trimetric to adjust the meter that reads the voltage drop across the shunt--Or they may have a "dead zone" adjustment (i.e., +0.2 amps to -0.2 amps reads zero on the meter).

    Hmmm... Looking at the meter manual, you can adjust the Volts reading, but not the shunt current (microVolts) reading.

    http://www.bogartengineering.com/wp-content/uploads/docs/TM-2030 Users Instructions11-01-16.pdf

    Since it is not adjustable (that I can find)... Verify the meter is working correctly. You want good electrical connections on both ends of the shunt voltage meter wiring--If one end is loose/corroded/dirty, you may get some "stray voltages".

    Take the two wires off the shunt and short them together--What does the Amp Meter read now?

    Make sure that G1 (meter ground goes to the battery). And that Sense Ground goes to the system ground side Kelvin contact on the battery shunt.

    http://www.bogartengineering.com/wp-content/uploads/docs/TM-2030Install Instructions.pdf

    Lastly, G2 (sense ground) and Sense should be twisted pair wires ideally (keep magnetic interference from other devices/AC wiring/etc. from coupling into the microvolt meter of the shunt interface).

    That is about all I can think of without calling the mfg. for support.

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