Step Down Transformer

System
System Posts: 2,511 admin
in PV Installers Forum - NEC, Wiring, Installation #1
My question relates to the minimization of line losses. I am installing a 10 kW ground mounted solar system in Ontario in a grid-tied application. I know that my inverter is available in both 240 V and 600 V output configurations. Would there be economic benefit in utilizing the higher voltage and providing a step down transformer to nominal 240 V at the point of connection to the meter, in order to reduce line losses for cable distances of 400 ft, assuming a 4 AWG aluminum conductor? Or could the cost more reasonably be spent in going to a 2 AWG aluminum conductor or copper? I have not been able to find reliable pricing on the step down transformer, so don’t have enough data to answer this question myself.
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
    Re: Step Down Transformer

    For long distance, I would perfer the high voltage and transformers, gives a little bit of isolation. Look for transformers on ebay, or maybe your utility has some.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #3
    Re: Step Down Transformer

    That may or may not be a good solution... Transformers can have upwards of ~5% losses... So you well end up with more losses with the transformer than without.

    I would probably go with the larger gauge cable--but, as we say, run the numbers for both setups (plus research transformer losses both under power and idling) and see what works out best.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • stephendv
    stephendv Solar Expert Posts: 1,571 ✭✭
    #4
    Re: Step Down Transformer

    Couldn't you move the inverter itself close to the meter, so that you run high voltage DC to the inverter, then only a short run for 240AC?
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