NonStop S-Series Planning and Configuration Guide (G06.25+)

Site Planning and Preparation
HP NonStop S-Series Planning and Configuration Guide—523303-015
12-6
Planning for System Power
Planning for System Power
Considerations
For detailed information about planning for system power, contact your HP trained
service provider. The following is a partial list of considerations:
•
Design your computer site to satisfy the requirements in this guide as well as
national and local electrical codes.
•
If you are upgrading an existing site to meet the specifications for a new system,
your service provider can assist you in determining the existing electrical power
resources available at your site.
•
Power installation must be done only by a licensed electrical contractor.
•
Your site might have local regulations and safety information concerning site
preparation and power installation. Your site must comply with any local codes as
well as with the requirements in this guide.
•
HP highly recommends that the design, installation, and maintenance practices for
electrical power and grounding of computer equipment follow the guidelines in
IEEE standard 1100-1992, IEEE Recommended Practice for Powering and
Grounding Sensitive Electronic Equipment. Following these practices minimizes
the likelihood of equipment disturbance due to power transients, noise, and
grounding problems.
•
An isolation transformer is recommended for computer rooms and large system
installations. An isolation transformer reduces noise or transients from nearby
loads; steps down voltages when necessary; provides a separately derived, final
point of electrical service for computer equipment; and helps keep common mode
voltage potentials within acceptable performance limits. The isolation transformer
must be within 75 feet (22.9 meters) of the system equipment.
•
There must be no more than 3 volts root mean squared (rms) difference between
neutral and ground.
•
Earth grounding and grounded neutral are required for the AC power source.
Considerations 12-6
Branch Circuits 12-8
Uninterruptible Power Supplies (UPSs) 12-8
Ethernet Switches or Hubs 12-9
System Enclosures 12-9
Peripheral Devices 12-9
AC Power Cords 12-9