amp discrepancy ?

arby
arby Solar Expert Posts: 108 ✭✭
in Off Grid Solar & Battery Systems #1
Battery bank in float mode, inverter and all loads turned off,
 trimetric shows .4 amps going in, midnite classic 200 showing 1.6 amps going in.
 Out of curiosity I wonder why the difference?
 
3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #2
    Is the breaker off to the inverter?
    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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  • arby
    arby Solar Expert Posts: 108 ✭✭
    #3
    The inverter is turned off and the main breaker into the cottage is turned off as an extra measure.
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,102 ✭✭✭✭✭
    #4
    What size and length wire from the controller to the shunt? Are all connections sound, low resistance? Do you have a breaker between the CC and Battery?

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #5
    have you re-torqued all the connections since assembly?  It needs to be done annually...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #6
    arby said:
    The inverter is turned off and the main breaker into the cottage is turned off as an extra measure.

    If it is not disconnected from the battery (breaker off) it might still be using some energy. You are trying to track down a pretty small amount of energy @50 watts, it may still be in some sort of idle mode even off while connected, likely only 8-10 watts, but you aren't hunting for a huge amount.

    If you don't have the Whiz Bang Jr attached, some of it might be energy consumed by the charge controller since the shunt the Midnite sees would be internal. I think they use @5 watts... but recall they are higher than other charge controllers.
    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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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #7
    @arby
    My trimetrics seem to show some sort of phantom load as well, even with all breakers off. It's on my to-do list to figure out this summer so would be interested if you figure it out first.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • arby
    arby Solar Expert Posts: 108 ✭✭
    #8
    "If you don't have the Whiz Bang Jr attached, some of it might be energy consumed by the charge controller since the shunt the Midnite sees would be internal. I think they use @5 watts... but recall they are higher than other charge controllers."

     Yes I was reading the Whiz Bang. I guessed that maybe the CC was using the extra amps.
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #9
    Mine are out by ~1a as well, and controller at <5w wouldn't account for all of it. My guess is it's a setting or calibration thing with the trimetric, but only a guess. A bit of a mystery to solve at some point.

    I do have a problem with CC self consumption as my panels have been had snow cover problems over the last two winters, and logged data is consistent with self consumption of 3-4w on controllers. I'm going to address that by adding winter oriented panels on PWM cotrollers and likely turning off Classics.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • arby
    arby Solar Expert Posts: 108 ✭✭
    edited March 2017 #10
    Well, I was impressed that it was only taking .4 amps to keep the 400 amp hour bank floating at about a temperature adjusted 58 volts. It was very cold and sunny that day and I hadn't turned the system on for two weeks. Stayed at my friend's cottage across the lake. Even at the  whiz bang's 1.6 amps I was impressed. :)
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
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  • boB
    boB Solar Expert Posts: 1,032 ✭✭✭✭
    #11
    When you see this happen at low amps like this, try turning the Classic off and back on again or better, go into the MODE menu and turn the mode off and back on.  See if that makes it come back in line with the Trimetric and/or WB Jr. in case drift was a problem

    The current sense in the Classic is very good but it's not perfect and has to be adjusted carefully at the factory...  Also, battery current should be a wee more accurate than input PV current.

    The  internal shunts look at the positive lines where the Trimetric and WB Jr. measures at the negative line into the battery - terminal.

    FYI, the common negative line from the Classic terminal, if only one single wire is used to tie to battery negative/common, will show difference between input and output current of the Classic, so just be aware of that.  That isn't a problem with the common shunt to battery minus though because the everything else is tied at the battery minus bus.

    There IS an adjustment pot accessible but I wouldn't touch that one just yet.

    boB
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  • arby
    arby Solar Expert Posts: 108 ✭✭
    #12
    Nice, Thanks. Will do that next time I'm up at the cottage.
    3310 watts panels, Classic 200 controller, 8 Surette S530's, Xantrex 5548 inverter, Honda EX5500 backup Genny.
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