HP 9000 rp5400 Servers - Manual (Page 148)

preventing circuit breakers from tripping when needed or can contribute to a buildup of high
frequency noise.
CAUTION: Connections that are too loose or too tight can have a high impedance that cause
serious problems, such as erratic equipment operation. A high impedance connection overheats
and sometimes causes fire or high temperatures that can destroy hard-to-replace components
such as distribution panels or system bus bars.
Wiring connections must be properly torqued. Many equipment manufacturers specify the proper
connection torque values for their hardware.
Ground connections must only be made on a conductive, nonpainted surface. When equipment
vibration is present, lock washers must be used on all connections to prevent connection hardware
from working loose.
Data Communications Cables
Power transformers create high-energy fields in the form of electromagnetic interference (EMI).
Heavy foot traffic can create electrostatic discharge (ESD) that can damage electronic components.
Route data communications cables away from these areas. Use shielded data communications
cables that meet approved industry standards to reduce the effects of external fields.
Environmental Elements
The following environmental elements can affect an hp server installation:
•
Computer room preparation
• Cooling requirements
• Humidity level
• Air conditioning ducts
• Dust and pollution control
• Electrostatic discharge (ESD) prevention
• Acoustics (noise reduction)
Computer Room Preparation
The following guidelines are recommended when preparing a computer room for an hp server:
•
Locate the computer room away from the exterior walls of the building to avoid the heat
gain from windows and exterior wall surfaces.
• When exterior windows are unavoidable, use windows that are double or triple glazed and
shaded to prevent direct sunlight from entering the computer room.
• Maintain the computer room at a positive pressure relative to surrounding spaces.
• Use a vapor barrier installed around the entire computer room envelope to restrain moisture
migration.
• Caulk and vapor seal all pipes and cables that penetrate the envelope.
• Use at least a 12-inch raised floor system for minimum favorable room air distribution system
(underfloor distribution).
• Ensure a minimum clearance of 12 inches between the top of the hp server cabinet and the
ceiling to allow for return air flow and ensure that all ceiling tiles are in place.
• Allow 18 inches (or local code minimum clearance) from the top of the hp server cabinet to
the fire sprinkler heads.
Cooling Requirements
Air conditioning equipment requirements and recommendations are described in the following
sections.
148 General Site Preparation Guidelines