Power cords and receptacles: The storage subsystem ships with two jumper
cords used to connect to the rack PDU. Youmust purchase the power cords that
are appropriate for use in a typical outlet in the destination country. See
Appendix D, “Power cords,” on page 179 for more information.
Heat output, airflow, and cooling
See “Airflow and heat dissipation” on page 21 for heat output, airflow, and cooling
specifications.
Note: In general, disk subsystem reliability tends to decrease as the ambient
temperature of the environment in which it is being used increases. The
ambient temperature in the immediate area of the disk enclosure unit must
be kept near 22° C (72° F), or lower, to provide better reliability.
When racks that contain many storage subsystems are to be installed together, the
following requirements must be met to for the storage subsystems to be cooled
adequately:
vAir enters at the front of the rack and leaves at the back. Toprevent the air that
is leaving the rack from entering the intake of another piece of equipment, you
must position the racks in alternate rows, back-to-back and front-to-front. This
arrangement is known as “cold aisle/hot aisle” and is shown in Figure 11on page
25.
vWhere racks are in rows, each rack must touch the rack that is next to it to
reduce the amount of hot air that can flow around from the back of the rack into
the intakes of the storage expansion enclosures that are in that rack. Use Suite
Attach Kits to completely seal any gaps that remain between the racks. For
details about Suite Attach Kits, contact your marketing representative.
vWhere racks are in rows front-to-front or back-to-back, a gap of at least 1220 mm
(48 in.) must separate the rows across the cold aisle.
vFor proper airflow in each rack, the rack filler plates must be installed in unused
positions. Also, all the gaps in the front of the racks must be sealed, including the
gaps between the storage subsystems.
24 IBM System Storage DS5020 Storage Subsystem: Installation, User’s, and Maintenance Guide