Table18-1 Typesof ma intenance for the power supply unit
Configuration Active/hot Active/cold Inactive/hot Inactive/cold Systemstopped
Building block configuration
Supported(*1) Unsupported
(*2)
Supported Unsupported
(*2)
Supported(*3)
*1: Active/hotreplacement can be perform ed only with a redundant configuration.
*2: Ifany physical partition is currently operating ,the cr ossbar box cannot be powered off.
*3: Allthe physical partitions must be powered off, an dthe s ystem must be completely shut down.
Table18-2 Maintenanceflow
Detailsof update process Replacement
1 Preparation 18.3
2 Removinga power supply unit 18.4
3 Installinga power supply unit 18.5
4 Restoringthe system 18.6

18.2.2 Maintenance flow

Table18-2 lists the sequence of the maintenance procedure for the power supply
units.

18.2.3 P recautions for replacement

Notethe foll owing points when replacing a power supply unit:
■There are two power supply units. Thus, the system can continue operating even
ifo ne of the units fails. Do not, however, operate the system for an extended
periodw hile one unit has failed.
■When replacing multiple power supply units, replace one unit at a time. If
redundancyof the power supply unit cannot be assured, then system-stopped
maintenance must be performed.
■Don ot force push the power supply unit into its slot. If excessive force is applied,
otherc omponents or the chassis may be damaged.
18.3 Enabling the Removal of a PowerSupply Unit
Thissectio n describes the preparations that must be completed prior to the removal
Chapter18 MaintainingthePower Supply Units of the Crossbar Box 319