IBM DS3500, Installation, User & Maintenance Manual

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Site wiring and power
The storage subsystem uses wide-ranging redundant power supplies that
automatically accommodate voltages to the ac power source. The power supplies
operate within the range of 90 V ac to 264 V ac, at a minimum frequency of 50 Hz
and a maximum frequency of 60 Hz. The power supplies meet standard voltage
requirements for operation both inside the U.S.A. and outside the U.S.A. They use
standard industrial wiring with line-to-neutral or line-to-line power connections.
The agency ratings for the DS3500 storage subsystem and EXP3500 expansion
enclosure are 6 amps at 100 V ac and 2.5 amps at 240 V ac. These are the overall
maximum operating currents for this system.
AC power recovery
After normal power is restored after a total ac power failure, the storage subsystem
performs power-on recovery procedures automatically without operator intervention.
Power cords and receptacles
The storage subsystem comes with two jumper cords that are used to connect to
the rack PDU. You must purchase the power cords that are applicable for use in a
typical receptacle in your country. See “Power cords” on page 138 for more
information.
Heat output, airflow, and cooling
Air enters at the front of the DS3500 storage subsystem and EXP3500 expansion
enclosure and leaves at the back. Allow at least 30 inches in front of the DS3500
storage subsystem and EXP3500 expansion enclosure and at least 24 inches at the
rear for service clearance, proper ventilation, and heat dissipation.
When racks that contain many DS3500 storage subsystems and EXP3500
expansion enclosures are to be installed together, the following requirements must
be met to ensure that the devices 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/hot aisle” and is shown in Figure 13 on page
16.
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 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 IBM marketing representative or authorized
reseller.
v
Where racks are in rows front-to-front or back-to-back, gaps of at least 122 cm
(48 in.) must separate the rows across the cold aisle (see Figure 13 on page 16).
v
To 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 subsystems.
Chapter 1. Introduction
15