Specifications

Electrical Requirements
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• Will the intended location enable you to conveniently perform routine operations,
such as loading and unloading tapes or other media, attaching cables, and so on?
• Is the floor of the intended final location strong enough to support the weight of the
system and any future expansions?
Large systems should be installed in computer rooms with raised floors. Pay
particular attention to floor loading and weight distribution in this case.
Floor-loading specifications are typically calculated by averaging the total chassis
weight that is distributed over the entire footprint of the chassis. Because the
chassis sits on four casters or four leveling pads, the load at each of these four
points is greater.
• Have you considered the site preparation cost and ease of installation at this
location?
• Does the intended location of the system allow for future expansion plans?
Electrical Requirements
SGI Origin 3900 server systems require electrical resources beyond those that are
normally provided in a typical office environment. The following sections describe those
requirements in general. These sections, along with the data presented in subsequent
sections, can help you determine the exact requirements for the new system. Table 2-1
lists the electrical service requirements.
Table 2-1 Electrical Service Requirements
Electrical Service Requirement
Phase imbalance 5% maximum (line-to-line,
line-to-neutral)
Voltage harmonics 5% maximum total, 3% largest
Voltage deviation from
sine wave
+5% to -10%
Voltage modulation 3% maximum
Transient voltage surges +5%
Transient voltage sags -5%
Frequency tolerance 5%
Frequency rate of change Less than 1.0 Hz during any 10-cycle
period