Ups Requirements - Fujitsu M10 Series Installation Planning Manual

CHAPTER 6 Power Supply Facilities
6.3

UPS Requirements

An Uninterruptible Power Supply system (UPS) supplies power to server systems
constantly under power failures even in a huge magnitude of power failures.
Instantaneous voltage drop of commercial power generally occur by thunder. The
chance of occurrence of instantaneous voltage drop depends on the location of the site
(in Japan, three to four times in a year). The typical interruption time of power supply
is said between 0.07 to 2 seconds.
Generally, power distribution circuits of server systems can maintain the performance
under power interruption at magnitude of 0.01 second. When the lower power supply
or power interruption sustains over 0.01 seconds, operation of server systems is
disabled, and this may lead to system down. It is important to avoid instantaneous
system down since longer time must be spent to reactivate the server systems, and
applications may interrupt for long time accordingly. Not only that, important files
may be destructed. Use UPS to prevent such instantaneous power failures. UPS
distributes to components in the server system in operation by its built-in batteries
under such interruption of commercial power supply.
UPS examination items are explained below.
Note that if the UPS is installed regardless of the following requirements, the
requirements of the server system and the performance of the UPS mismatch, and the
user's server system may be damaged, or significant data may be destroyed.

UPS load specifications
 Prediction of rush current and load variation of the equipment
 UPS terminating requirements

Effect of high-frequency noise
 Life-span of a UPS built-in battery
 Discharge of UPS built in battery

Requirements for power interruption
 Leakage current
 Load rating
 Power rating (for printer connection)
 Checking the UPS environmental specifications and the warranty term
72 C120-H007-08EN