Narrative of the Case 1 Shutdown

Timeline of Shutdown Steps shows a typical shutdown and restart due to utility power failure. Following is an analysis of the timeline of events.

  1. At 0 seconds, power fails and the UPS starts providing battery power. PowerChute plus generates the UPS On Battery event and begins the 120 seconds of pre-shutdown delay configured for that event.

  2. At 5 seconds, PowerChute plus broadcasts the first shutdown message to users. At 30 second intervals, PowerChute plus broadcasts the message again until the System Shutdown Starting event occurs.

  3. At 2 minutes, PowerChute plus generates the System Shutdown Starting event and starts the 60 second delay configured for that event.

  4. At 2 minutes 5 seconds, a user-specified command file executes.

  5. At 3 minutes (after the command file has run), the following events occur.

    a.
    PowerChute instructs the operating system to shut down.

    b.
    PowerChute generates the System Shutdown Complete event.

    c.
    PowerChute plus issues the UPS Turn Off Delay instruction from within the UNIX shutdown script. During the UPS Turn Off Delay period, the operating system completes the remaining portion of the shutdown procedure. Because the UPS Turn Off Delay is issued from within the shutdown script, a brief additional delay may occur before the UPS Turn Off Delay begins, which briefly delays the turnoff of the UPS

  6. The UPS, unless it is a Back-UPS, turns off its outlets and goes into sleep mode.

To complete all the events in the timeline in this example, the UPS must run on battery power for at least 200 seconds (3 minutes and 20 seconds). Therefore, for the UPS to complete the shutdown procedure properly, the UPS runtime shown on the Run Time bar graph must be greater than or equal to 200 seconds.

UPS on Battery delay
+
System Shutdown Starting delay
+
UPS Turn Off Delay
must be less than or equal to
Run Time bar graph time
120 seconds + 60 seconds + 20 seconds <= 200 seconds.

Timeline of Shutdown Steps