Power And Site Wiring Requirements For Models With Power Supply And Fan Units; Heat Output, Airflow, And Cooling - IBM System Storage DCS3700 Installation, User's, And Maintenance Manual

Power and site wiring requirements for models with power supply and fan units

The storage expansion enclosure uses wide-ranging redundant power supplies that automatically
accommodate voltages to the power source. The power supplies operate within the ranges specified in
Table 12 on page 20. The power supplies meet standard voltage requirements for both domestic (inside
USA) and international (outside USA) operation. They use standard industrial wiring with line-to-neutral
or line-to-line power connections.
The agency voltage and current ratings for the DCS3700 storage expansion enclosure are 200 VAC - 240
VAC and 7.56 A - 6.30 A.
Power recovery after a power failure: After a total power failure, after normal power is restored, the
storage expansion enclosure performs power-up recovery procedures automatically without operator
intervention.
Power cords and receptacles: The DCS3700 ships with two jumper cords with IEC C19 plug on one end
and IEC C14 plug on the other end that are used to connect to the rack PDU outlets. It is not shipped
with the power cords that can be used to connect it directly to an electrical outlet in the destination
country. You must purchase the power cords that are appropriate for use in a typical outlet in the
destination country. See Appendix D, "Power cords," on page 153 for more information.

Heat output, airflow, and cooling

See "Airflow and heat dissipation" on page 19 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.
When racks that contain many storage expansion enclosures are to be installed together, the following
requirements must be met to ensure that the storage expansion enclosures are adequately cooled:
v Air enters at the front of the rack and leaves at the back. To prevent 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 and hot aisle and is shown in
Figure 14 on page 22.
v Where 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. You should use Suite Attach Kits to completely seal any gaps that remain between
the racks. For details about Suite Attach Kits, contact your marketing representative.
v Where 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.
v To ensure correct 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 expansion
enclosures.
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Chapter 1. Introduction