Setting this to a value other than -1 schedules a specific receptacle to turn off after that many seconds (0 meaning immediately), while setting it to -1 aborts a pending shutdown for that outlet; if set while the UPS is on battery, the outlet will automatically come back on once power returns without needing upsRecepOnDelaySecs. It gives an admin per-outlet remote power-off scheduling, for example to shed a non-critical load first during an outage. For example, setting upsRecepOffDelaySecs to 0 on the outlet feeding a test server immediately cuts power to just that outlet.