This read-only INTEGER reports the status of the line input power feeding the supply, with defined values including noError, lineOverVoltage, lineUnderVoltage, lineHit, brownOut, and linePowerLoss. It helps an admin distinguish a facility power-quality problem from an internal supply failure when a power alert fires. For example, several supplies across a rack simultaneously reporting brownOut(5) points to a facility power event rather than a coincidental hardware failure across multiple units.