General Site Preparation Guidelines; Electrical Factors; Synopsis; Ac Electrical Distribution System - HP Rp3440-4 - 9000 - 0 MB RAM Manual

1 General Site Preparation Guidelines

This guide contains recommendations and best practices to improve site efficiency and tolerance
before installing or operating an HP high-end or mid-range server system. This general
information is intended for different server models and customer sites around the world and is
not a substitute for recommendations or requirements from the manufacturer of a specific product.
NOTE: See the specific server service guide for the guidelines required to support the specific
server.
The following information provides general principles and practices to consider before installing
or operating the system. These guidelines apply to all customer environments that an HP product
is likely to be installed in:
• Controlled computer room
• Controlled office
• Uncontrolled office/home
• Light industrial
• Mobile/portable
However, the implementation of these guidelines will vary from customer to customer and from
one environment to another.

Electrical Factors

Synopsis

AC Electrical Distribution System

HP recommends use of an electrical distribution system that exceeds normal electrical guidelines.
This recommendation is based on experiences with HP customers who have a low occurrence
of unexpected interruptions. As your system availability needs increase, these recommendations
become more important.
Recommended electrical distribution hardware includes receptacles, AC wiring, conduits, and
breakers that are sized for maximum-rated loads, rather than for typical loads. Do not exceed 75
feet (23 m) between the receptacle and nearest X0 bond and the transformers because connection
points can become loose over time and subject to loading problems.
HP recommends using a higher input voltage to the stepdown transformer within 75 feet (23
m). For example, if 480-volt current is available in the building, ensure that distribution
transformers in the server room are 480/208-volt stepdown. In an optimum electrical distribution
system:
• Electrical infrastructure is rated for maximum load.
• The distance from a receptacle to power source X0 is less than 75 feet (23 m).
• There are no daisy-chained receptacles or hot, neutral, or ground wires.
• The system is sourced from higher distribution voltages.

AC Power Quality Devices

HP products have a wide range of voltage tolerances. In general, approximately 10% of the
nominal voltage is sufficient for the marked electrical-rated voltage. The best operating margin
is in the middle of this range but your business needs will dictate the risk you can withstand.
Although utility-fed AC power is usually error free, your particular building or area might be
subject to local problems.
Electrical Factors 7