HP Array Controller HSG V8.7 Software - Manual (Page 128)

Power Distribution
6–2 UltraSCSI RAID Enclosure
Note
Proper operation of the controller cache modules requires
ECBs. Refer to the array controller documentation for
discussion on how to use the ECBs.
Power System Overview
In any RAID subsystem, the elimination of single points of failure is
taken into consideration. Designing systems with redundant power
capabilities is one way to eliminate single points of failure.
The following major components compose the power system:
• AC power sources
• AC input boxes
• Power cords
• Shelf power supplies
Note
The ac input box power cords are integral to the data center
cabinets. For the departmental server cabinets, the
user-supplied power cords are country-specific.
The drive SBB shelf ac power cords are integral parts of the
UltraSCSI enclosures.
Power Configurations
For all StorageWorks products with the capability of using redundant
power, the power configurations definitions follow a n+x format. In
this format, n is the minimum number of power supplies required for
operation and x is the number of redundant power supplies. Each
UltraSCSI RAID enclosure requires a minimum of four (n) power
supplies to operate and a specified number of power supplies for
redundancy purposes.