Flat capped output means the plant or inverter power trace runs as a flat line during good sun and does not follow rising irradiance. When the flat top sits at the inverter AC rating on sunny days, it points to inverter clipping, where the array can supply more DC power than the inverter can deliver as AC. Clipping is often a planned design choice that buys extra morning and evening yield, so it is not always a fault. When the flat level sits below the inverter rating, or below the power the irradiance should support, it points to grid curtailment from operator dispatch, an interconnection limit, a plant controller command, a reaction to negative prices or a site export cap. During curtailment, inverter and tracker availability can look normal, so it is easy to log as underperformance by mistake. Check plant setpoints, inverter active power limits, dispatch records, meter output, battery charging behavior and curtailment flags before looking for equipment faults. Do not confuse this with an inverter voltage floor: clipping caps power, while voltage flooring is an MPPT limit caused by the DC voltage window.
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- sentence 1: support check: partial - Flat or non-rising output at high irradiance is supported, but the passages don't say 'good sun' explicitly. They do say saturation occurs at high irradiance and that output doesn't follow rising irradiance.
- sentence 4: support check: partial - The listed curtailment causes and the flat output below available power are stated, but the passage doesn't contrast this with the inverter rating or say a flat level below the rating points to curtailment.
- sentence 6: support check: partial - The detection method lists the items to compare, but the passages don't say to check them before looking for equipment faults. The workflow sorts constrained intervals by cause, and u9 only warns against chasing false equipment problems.
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