Voltage rise in microinverter systems is measured from which start to end point?

• A. Across the house
• B. From Point of Common Coupling to the last microinverter
• C. From Point of Common Coupling to the solar AC Isolator
• D. From Point of Common Coupling to the main service panel

Answer: (C)

Voltage rise is the extra voltage that can appear on the utility feeder when PV generation backfeeds into the grid. In a microinverter setup, the PV output flows into the building through the solar AC disconnect, which marks the boundary between the PV system and the house wiring. To quantify how much the PV backfeed raises the voltage, you measure from the Point of Common Coupling (where the building connects to the grid) to the solar AC isolator (the PV boundary switch). This path captures the portion of the circuit that the PV system actually influences, before any losses or loads inside the service panel and building are considered. Measuring to the solar AC isolator focuses precisely on the PV-induced voltage rise, whereas the other options either include loads or lack a defined boundary for the PV system.