Polarity of mnepv breaker between batteries and charge controller

blueskies
blueskies Registered Users Posts: 54 ✭✭
in Off Grid Solar & Battery Systems #1
Hi!  I have installed a breaker for each solar panel going to my charge controller.  These are all MNEPV breakers and boxes from Northern AZ.  The breakers indicate polarity sides with a (+) and a minus and so the positive solar panel wires go to the positive side and the neg. side will go to the charge controller.

Now I am getting ready to install a breaker from the batteries that will go to the controller.  Since all the afforementioned breakers are in place, the purpose of this breaker is to avoid frying the controller.  It seems to me that the purpose of this breaker is to prevent damage to the controller as a result of some type of fault in wiring or batteries between the controller.  So wouldn't it make sense to connect the battery side to the pos. side of the breaker and the controller to the neg side as this is the direction of the current I am concerned about?  And really, would these breakers not trip in any direction?

To avoid confusion - regardless of the pos/neg references of the breakers, all of this is actually on the positive wiring only and the negative wiring is not involved at all.

Thanks for any insight!!!
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Comments

  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    #2
    Yes the positive of the breaker goes to positive of battery, reason, on fault in controller battery is more positive than controller, even though in normal operation the c.c. Would be more positive than battery, got that from boB at MidNite 
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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  • blueskies
    blueskies Registered Users Posts: 54 ✭✭
    #3
    Thanks Tec!!! and boB too!
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #4
    Tecnodave said:
    Yes the positive of the breaker goes to positive of battery, reason, on fault in controller battery is more positive than controller, even though in normal operation the c.c. Would be more positive than battery, got that from boB at MidNite 
    Or in other words the positive goes to the point of highest potential energy, the battery in this case. 
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
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  • Tecnodave
    Tecnodave Registered Users Posts: 437 ✭✭✭✭
    #5
    McGivor,

    yes that hat is correct, both boB and Halfcrazy has said that on MidNite forum.
    2 Classic 150, 2 Kid, 5 arrays 7.5 kw total  2ea.  2S6P Sharp NE-170/NE-165, 1ea. 12P Sanyo HIT 200,  2ea. 4/6P Sanyo HIT 200, MagnaSine MS4024AE, Exeltech XP-1100,  2 Banks L-16 battery, Rolls-Surette S-530 and Interstate Traction, Shunts with whizbangJr and Bogart Tri-Metric, iCharger i208B  dc-dc buck/boost converter with BMS for small form lithium 8S 16650 or LiFePO4,
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