Acceptable voltage drop for short distances close to zero percent

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Q:

Good explanations of all the details per wire sizing. The altE store and many others have their calculators to sell us wire, combiner boxes, and OCPD’s.  I see most of them default with 2-3% voltage drops max for wire sizing per distance, and inverter wattage.

A:

If your distance is short, you should be very close to 0% voltage drop. It is all relative to the price of the wire and the price of the rest of the PV system. The increased price on 5 feet of wire is much less than the increased price of 500 feet of wire. 500 feet of wire might be a consideration for 3% voltage drop, but 5 feet... Up-sizing that wire would be relatively cheap to consider losing 3% of your energy for 30 years just to save $5.

Sean

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