Issue:
How does the operating system restart when AC has been restored?

Product:
PowerChute Network Shutdown


Environment:
All supported operating systems

Cause:
Computer/Server restart automatically required

Solution:
PowerChute is software running on a computer or server. When the system is powered off, PowerChute is no longer available and, therefore, cannot restart the system. This is the same as if the user wants to create a text document. If the system is powered off, the text editor cannot run.

The system BIOS is responsible for automatically starting the system. Many systems available today use the ATX motherboard, which supports a soft switch to turn the system On and Off. The implementation of this soft switch includes a BIOS parameter, which defines the state the computer will enter when the power supply senses input power when plugged into the wall. This BIOS parameter can have any one of three values :

ALWAYS ON: When power is cycled, the system automatically turns on and boots up.

ALWAYS OFF: When the power is cycled on, the system stays off until the user manually hits the On/Off soft switch.

LAST STATE: When power is cycled on, the system will either come on or stay off, depending on whether it was on or off when the power was lost.

Most computer/server manufacturers set this parameter to Last State, and some set it to Always Off. It is improbable to find the Always On parameter setting. In many cases, the computer/server manufacturer permits the user to change the value of this parameter by using the system setup menu, which can be accessed before the operating system loads when the computer/server is turned on.

Our recommendation is to set the BIOS to Always On.

Once the BIOS has been configured to allow the OS to restart, the UPS or outlet group must be told to power off. To power off the UPS or outlet group, configure the UPS shutdown within PowerChute.

If the UPS or outlet group is not commanded off and AC is restored during the shutdown process, the UPS will not cut output, so the BIOS will not restart the system.

NOTE: Some Smart-UPS only allow turning off the UPS, others allow for turning off the UPS or the outlet group, and PowerChute cannot command down some 3-phase UPS.

Released for: Schneider Electric Malaysia