NonStop NS1200 Planning Guide

Power Quality
This equipment is designed to operate reliably over a wide range of voltages and frequencies,
described in “Enclosure AC Input” (page 43). 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 server 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 an Integrity NonStop NS1200 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 43).
Uninterruptible Power Supply (UPS)
Modular cabinets do not have built-in batteries to provide power during power failures. To
support system operation through a power failure, Integrity NonStop NS1200 servers require
either an optional UPS (such as the HP model R5500 XR UPS) installed in each modular cabinet
or a site UPS to support system operation through a power failure. This system operation support
can include a planned orderly shutdown at a predetermined time in the event of an extended
power failure. A timely and orderly shutdown prevents an uncontrolled and asymmetric
shutdown of the system resources from depleted UPS batteries. The HP model R5500 XR UPS
supports the OSM Power Fail Support function that allows you to set a ride-through time. If AC
power is not restored before the specified ride-through time period, OSM initiates an orderly
system shutdown. For additional information, see “AC Power Monitoring” (page 80).
Adding an R5500 XR UPS to a modular cabinet in the field requires removing the PDU on the
right side of the modular cabinet and installing HP extension bars that are compatible with the
UPS. A factory-installed UPS ships with the HP extension bars already installed on the right side
of the modular cabinet. The PDU and extension bars are oriented inward, facing the components
within the rack. Both the UPS and the ERM are 3U and must reside in the bottom of the cabinet.
32 Site Preparation Guidelines