IBM DS4800 - Redundant AC Power Connections to Controllers and Storage Expansion Enclosures

For details about power requirements, see “Electrical requirements” on
page 23.
10. Go to “Turning on the storage subsystem” on page 97.
Attention: Before you power on the DS4800 Storage Subsystem, the
DS4800 must be cabled to at least one storage expansion enclosure populated
with at least two drives. If at least two drives are not installed in each attached
storage expansion enclosure when you power on the DS4800, your standard
storage partition key will be lost and will need to be regenerated using
instructions on the IBM DS4000 Solutions and Premium Features Web site:
https://www-912.ibm.com/PremiumFeatures/
Additionally, if at least two drives are not installed in each attached storage
expansion enclosure, the resulting insufficient load to the storage expansion
enclosure power supply CRUs might cause the drive expansion enclosure
power supply CRUs to intermittently appear as failed and then reappear in an
optimal state, falsely indicating that the power supply CRUs are bad.
AC distribution unit
power cord
Controller power supplies
Storage expansion
enclosure
power supplies
Rack power cable connector
Rack power cable
AC distribution units
f10ug060
Figure 68. Redundant AC power connections to controllers and storage expansion enclosures
Chapter 3. Cabling the storage subsystem 91