NonStop NS2400 Series Planning Guide

EPO Requirement for HP R12000/3 UPS
The rack-mounted HP R12000/3, UPS is supported for a three-phase power configuration. This
UPS contains batteries, has a remote EPO (REPO) port, and can be optionally installed in a modular
cabinet. For site EPO switches or relays, consult your HP site preparation specialist or electrical
engineer regarding requirements.
If an EPO switch or relay connector is required for your site, contact your HP representative or see
the HP 3 Phase UPS User Guide for connectors and wiring for the HP R12000/3 UPS at:
http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c01079392/c01079392.pdf
Electrical Power and Grounding Quality
Proper design and installation of a power distribution system for a NonStop NS2400 series system
requires specialized skills, knowledge, and understanding of appropriate electrical codes and the
limitations of the power systems for computer and data processing equipment. For power and
grounding specifications, see “AC Input Power for Modular Cabinets” (page 67).
Power Quality
This equipment is designed to operate reliably over a wide range of voltages and frequencies,
described in “Enclosure AC Input” (page 69). However, damage can occur if these ranges are
exceeded. Severe electrical disturbances can exceed the design specifications of the equipment.
Common sources of such disturbances are:
• Fluctuations occurring within the facility’s distribution system
• Utility service low-voltage conditions (such as sags or brownouts)
• Wide and rapid variations in input voltage levels
• Wide and rapid variations in input power frequency
• Electrical storms
• Large inductive sources (such as motors and welders)
• Faults in the distribution system wiring (such as loose connections)
Computer systems can be protected from the sources of many of these electrical disturbances by
using:
• A dedicated power distribution system
• Power conditioning equipment
• Lightning arresters on power cables to protect equipment against electrical storms
For steps to take to ensure proper power for the servers, consult with your HP site preparation
specialist or power engineer.
Grounding Systems
The site building must provide a power distribution safety ground/protective earth for each AC
service entrance to all NonStop system equipment. This safety grounding system must comply with
local codes and any other applicable regulations for the installation locale.
For proper grounding/protective earth connection, consult with your HP site preparation specialist
or power engineer.
Power Consumption
In a NonStop NS2400 series system, the power consumption and inrush currents per connection
can vary because of the unique combination of enclosures housed in the modular cabinet. Thus,
the total power consumption for the hardware installed in the cabinet should be calculated as
described in “Enclosure Power Loads” (page 70).
Electrical Power and Grounding Quality 47