Fujitsu M10 Series Installation Planning Manual page 93

(7) Requirements for power interruption
The following specifications must be checked for selection of a UPS.
 Most of UPS cannot be started up under circumstance of power interruption. If
such startup is required, request the UPS manufacturer for modification.
 When part of system components are connected to UPS, and the rest of the
components are connected directly to the commercial power, the components
connected to commercial power supply may generate incorrect signals, and the
components malfunction may occur.
(8) Leakage current
If commercial power supply facilities have leakage shut-off unit, leak current from a
UPS may activate the shut-off unit. In such case, the following actions must be
considered.
 Increase the trigger voltage of the shut-off unit.
 Use a shut-off unit which does not trip easily by microwave leakage current.
 Install an insulation transformer between the UPS and the commercial power
outlet.
(9) Load rating
When operating UPS in higher power factor than its rated power factor, use the UPS
in reduced output voltage. For example, a rating power factor of a 10 kVA/8 kW rated
UPS is 0.8.
When connecting load lower than 0.8 power factor to the UPS, up to 10 kVA load can
be connected. When connecting load grater than 0.8 power factor, reduce the load to
the calculated value by the formula below.
C120-H007-08EN
kW
8
------------------ -
= 0.8
kVA
10
kW
8
----------------------------------------------------------- -
=
power factor of load
 
load kVA
6.3 UPS Requirements
75