Interconnect-Battery Unit; Power Supply-Fan - IBM DS4800 Installation, User And Maintenance Manual

Levers in
released
position
Figure 6. Power supply-fan
Information about the condition of the power supplies, fans, and battery charger is
conveyed by indicator lights (LEDs) on the front of each of the power supply and
fan units and on the interconnect-battery unit. You must remove the front bezel to
see the LEDs. ("Power supply-fan LEDs" on page 125 identifies the indicator LEDs
on a power supply and fan unit and explains the conditions that each LED
indicates.)
Note: The order of the LEDs on the power supply and fan unit is different
In the DS4800 Storage Subsystem, the right power supply and fan unit is linked to
controller A, and the left power supply and fan unit is linked to controller B. To
increase protection against power loss, always make sure that both power supply
and fan units are operational.

Interconnect-battery unit

The interconnect-battery unit is a removable midplane that provides cross-coupled
signal connection between the controllers. The control output from each controller is
connected to the control input in the alternate controller. An audible alarm is
mounted on the interconnect-battery unit display board. A mute switch for the
audible alarm is also mounted on the same board. The interconnect-battery unit
also provides the electrical communication path between the power supply and fan
units and allows their power supplies to load-share and to charge the cache-backup
battery packs. There are two cache-backup battery packs mounted inside the
interconnect-battery unit.
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IBM System Storage DS4800 Storage Subsystem: Installation, User's, and Maintenance Guide
Latch
Latch
depending on whether the power supply and fan unit is installed in the left or
right bay.
Power supply-
fans
Levers in
latched
position