converter hook up

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jchamp
jchamp Registered Users Posts: 22 ✭
in Solar Beginners Corner #1
Hey guys. I am trying to set up two 45 watt kits. I have ran my panel wires to the controler, the cables from the controler to the batterys. now do I connect my inverter to the batterys or to the back of the controler? Thanks, James
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #2
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    Re: converter hook up

    What are you calling "your converter"?

    Icarus
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  • jchamp
    jchamp Registered Users Posts: 22 ✭
    #3
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    Re: inverter hook up

    sorry I meant inverter I have a 1200 watt inverter.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #4
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    Re: converter hook up

    Generally, make all your common connection points to the battery with separate wires/fuses to each of the loads/sources to prevent short circuits from catching the wiring on fire.

    The systems usually work best when the battery is made the "heart" of the system (all wiring home-run back to the common +/- connection points/bus bars).

    Certainly things can be done differently--but it can get a bit more complex trying to figure out the fusing and wire gauges. Also, sometimes you may get interactions between a charge controller and various loads (such as oscillations as inverters and charge controllers adjust their inputs/outputs based on how they interact together).

    Also, separate runs make for easier fault isolation (blow fuse for inverter, but charge controller and DC lights still work) and one failure does not cause other issues.

    -Bill

    PS: Example here--45 watt panel and controller is ~4 amps each.

    1,200 watt inverter can take over:

    1,200 watts * 1/0.85 eff * 1/10.5 volts min batt = 134 amps

    So the wiring for the inverter has to be about 30+x heavier vs the charge controller....

    In general--the cable for the inverter to battery connections should be heavy and short. The cables to the charge controller, short. To the solar panels can be farther away.

    There is probably no advantage to share the inverter cables with the charge controller function.

    Tie all common connections back at the battery / battery bus.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #5
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    Re: converter hook up

    You do realize that 90 watts of panel will give you ~ 180 watt/hours net/net/net out of the battery on a good day. Enough to power your 1200 watt inverter to 1000 watts for about 10 minutes per day? Or combination there of, such as a 15 watt bulb for ~12 hours.

    Tony
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  • jchamp
    jchamp Registered Users Posts: 22 ✭
    #6
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    Re: converter hook up

    so far I have no idea what 90 watts of power will do for me. I am new and learning. where can I find info and pictures on the way I can install fuses to protect my tv, lites and so. maybe the three fuses on the back of the inverter for each outlet are for that?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #7
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    Re: converter hook up

    James,

    I will take a shot at answering this question--but please ask if I missed your point.

    Fusing/breakers protect the wiring, not the attached devices.

    So, using 120 VAC Branch Wiring as an example... Your 120 VAC TV, Radio, Lights, extension cords, etc., are all designed and rated to connection to a wall plug with a rating of 15-20 amps maximum (maximum fuse/breaker rating for a branch circuit).

    So any source (such as an inverter) that has a maximum of 15-20 amp output (at 120 VAC) will not need any further fuses/protection for attached equipment.

    If the equipment itself needs further protection (such as inside a TV, or a string of Christmas tree lights), they must include there own internal fuse for their protection (such as the small fuse in the plug of a string of modern Christmas tree lights).

    So--in the example with 1,200 watt inverter--its output current is ~10 amps maximum, so there is no requirement for extra fuses/breakers to connect your TV, Radio, etc. assuming you are using UL rated extension cords, power strips, etc.

    If, as an example, you run a very light load (say a 4 watt 120 VAC CFL fixture) for a 100' on a 20 awg set of wiring--then you would need a fuse/breaker rated around 2-5 amps to protect that run of small wire from your inverter connection to the lamp base--and the fuse should be located right at the inverter/power strip so that the entire run of wire is protected (vs placing the 1-5 amp fuse at the base of the lamp).

    Sort of confusing?

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