Plugs And Receptacles; Power Trends And Strategies - Compaq 226824-001 - ProLiant - ML750 Basics Manual

area of a data center to prevent the cascading effects of inrush, should a site experience a power
loss.

Plugs and receptacles

Two types of power cords provide connections between server products and utility power: power cord
assemblies and jumper cable assemblies. In general, power cord assemblies provide the main
connection from the AC power outlet to the server equipment, and they meet the standards for the
country from which they are ordered. (See Appendix C for complete information on NEMA and IEC
standard plugs and sockets.) Jumper cable assemblies provide the power connection between a
server and an intermediate device such as a PDU. Jumper cables universally employ IEC-type
connectors, which are rated for handling both high-line and low-line voltage.
A power cord assembly consists of a plug (male connector), a cord, and a receptacle (female
connector) as shown in Figure 16. A jumper cable assembly generally consists of a pin-and-sleeve-
style plug (male connector), a cord, and a receptacle (female connector).
Figure 16. Power cord assembly
Cord
Plug
Receptacle

Power trends and strategies

Power demand in data centers will continue to rise; the increasing power will result in increased heat
and greater heat dissipation issues. Data centers will need to allow for growth in the amount of power
supplied while continuing to focus on efficient use of existing power and cooling. An efficient data
center will offer expandable and efficient computing resources with optimized power usage.
Understanding the interaction between increased processor performance, greater storage
requirements, and the demand for more power requires thoughtful decisions about how to optimize
data center resources.
To minimize downtime, IT organizations must plan for and configure redundant hardware and
redundant power paths. Therefore, organizations will benefit if they migrate from using single power
cords (which provide no redundancy) to two cords for two paths (one for capacity and one for
redundancy), and then to four cords for four paths (two for capacity and two for redundancy).
The best choice for an organization may be easier to identify by considering costs with a long-term
view instead of a short-term view.
By any industry measure, server power densities are rapidly increasing. 3 In 2001, data centers
averaged four to six servers (5U to 7U each) per rack with corresponding wattage levels of 1,500 to
3 "Moving Toward Meltdown," Computerworld, October 6, 2003,
http://www.computerworld.com/hardwaretopics/hardwar e/story/0,10801,85639,00.html
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