When the system powers up, the fans come on at high speed. The fan speed slows as the system boots up. The powerstatus LED blinks until the boot-up sequence is complete. When the boot up is complete, the power status LED is steadilylit.AC PowerCAUTION: Ensure that the PSU is installed correctly. The AC power connector must be on the left side of the PSUand the status LED at the top of the PSU.Connect the plug to each AC power connector. Make sure that the power cord is secure.As soon as the cable is connected between the S5000 and the power source, the chassis is powered-up; there is noon/off switch.DC PowerConnect the plug to each DC receptacle. Make sure that the power cord is secure and the polarity is correct.As soon as the cable is connected between the S5000 and the power source, the chassis is powered-up; there is noon/off switch.Hot-Swapping Units in a StackYou can add, remove, or swap S5000 units in an existing stack. The units in the stack and the new units can be alreadypowered up or powered down. All units in a stack must run the same version of the operating system.The order in whichthe units come online or are added to or removed from the stack affects how the stack identifies them and how the unitsidentify themselves. This order influences unit numbers, management addresses, and other elements of theconfiguration file.Unit identification within the stack is determined by the identification algorithm you select. The default algorithm has theunits self-identify as Unit 0 through Unit last based on the order in which they come online. So, when setting up a newset of switches in a stack, you should have no trouble forcing the identification of the management unit and unit IDs bymethodically supplying power to the units in your preferred sequence.Similarly, when you add a unit to the stack, the unit is gracefully added as Unit last (the lowest unused number) with thecurrent configuration. Attaching a new unit may cause each unit in the stack to reload. The subsequent configurationfile in each unit includes the awareness of the new unit.If you have a preconfigured unit that you want to add to the stack, but you want to make sure that the configuration doesnot override the configuration of the stack, add the unit while it is powered down to avoid stack management conflicts.For more information about removing a unit from a stack and other stacking commands, refer to the Stacking chapter intheFTOS Configuration Guide for the S5000 Switch and the Stacking Commands chapter in theFTOS Command LineReference Guide for the S5000 Switch.42