Power And Site Wiring Requirements; Heat Output, Airflow, And Cooling - IBM System Storage DS5020 Installation, User's, And Maintenance Manual

v Power failures – If a total power failure occurs, the unit automatically performs a
Table 13. DS5020 ac power requirements
Nominal Voltage
Frequency (Hertz)
Idle Current
Maximum Operating Current
Maximum Surge Current
a.
factor
b.
factor

Power and site wiring requirements

The storage subsystem uses wide-ranging redundant power supplies that
automatically accommodate voltages to the ac power source. The ac power
supplies operate within the ranges specified in Table 13. The ac 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 ratings for the DS5020 storage subsystem are 6 amps at 100 VAC and
2.5 amps at 240 VAC. These are the overall maximum operating currents for the
DS5020 storage subsystem with ac power supply and fan unit CRUs.
AC power recovery: After a total ac power failure, after normal power is restored,
the storage subsystem performs power-up recovery procedures automatically
without operator intervention.
Power cords and receptacles: The storage subsystem ships with two jumper
cords used to connect to the rack PDU. 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 187 for more information.

Heat output, airflow, and cooling

See "Airflow and heat dissipation" on page 24 for heat output, airflow, and cooling
specifications.
Note: In general, disk subsystem reliability tends to decrease as the ambient
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:
v Air enters at the front of the rack and leaves at the back. To prevent the air that
26
IBM System Storage DS5020 Storage Subsystem: Installation, User's, and Maintenance Guide
power-up recovery sequence without operator intervention after power is
restored.
Typical voltage: 120 V ac, 60 Hz, assumes 72% power-supply efficiency and 0.99 power
Typical voltage: 240 V ac, 60 Hz, assumes 72% power-supply efficiency and 0.99 power
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.
is leaving the rack from entering the intake of another piece of equipment, you
Low Range
90 to 136 VAC
50 to 60 Hz
a
3.53 A
a
3.71 A
a
5.04 A
High Range
198 to 264 VAC
50 to 60 Hz
b
2.08 A
b
2.04 A
b
2.67 A