AC conductor voltage rise limiting

This action means sizing the AC conductors and laying out the branch circuits so the voltage rise between the inverter and the grid connection stays small. It prevents nuisance overvoltage trips caused by an undersized AC conductor. Grid-tied inverters must stop exporting when the voltage at their terminals goes above the allowed limit. Resistance in the system wiring adds to the grid voltage, so it can push an inverter over that limit. The main factors are conductor size and the distance to the point of common coupling. Too much wire resistance between the inverter and the grid can cause a repeated cycle: the inverter disconnects, reconnects after the set delay, and trips again as the voltage climbs back up. For microinverter systems, Enphase recommends keeping the total rise below 2% across all wire sections. Keeping the rise in the trunk cable below 1% is good practice. Conductor length tables give the maximum run for each wire size at a 1% rise. Center-feeding splits a branch into two sub-branches behind a single overcurrent device. In one example, the rise to the last microinverter fell from 1.32% with an end-fed circuit to 0.52% with center-feeding. Keeping the resistance of the leads to the AC terminals low also helps grid monitoring work properly. Lower conductor resistance cuts power loss and heat at the terminals and improves production. Limits: standard feeder voltage-rise guidelines may not be enough for fully populated microinverter branches. Wiring changes do not fix overvoltage that comes from high resistance in the distribution grid itself.

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• sentence 7: support check: partial - Standard guidelines possibly being insufficient for fully populated branches is stated, but the passages do not say wiring changes can't fix grid-resistance overvoltage; they only name grid resistance as a separate cause.
• sentence 7: review: partial - The passages say standard guidelines may not be enough for fully populated branches, but none says wiring changes cannot fix overvoltage caused by distribution-grid resistance. -->