Operation Overview; Figure 1.1 Single Line Diagram-Normal Operation: Load Powered By Ups Inverter - Mitsubishi Electric 9900B Series Owner Technical Manual

MITSUBISHI
ELECTRIC

1.4 OPERATION OVERVIEW

The UPS provides two power paths between the utility source and the critical load. Figure 1.1
shows the path for normal operation, with the load powered from the inverter. Figure 1.2 shows
the path for bypass operation, with the load supplied through the static bypass line.
A) Normal operation: Load power supplied by each system UPS inverter.
Figure 1.1 Single Line Diagram - Normal Operation: Load powered by UPS Inverter
CB
Bypass
Input
User
supplied
MCCB
CB
AC
input
User
supplied
MCCB
During normal operation, the path through the UPS inverter is used to power the load.
Referring to Figure 1.1: Input AC power is converted to DC by the Converter. DC power is
utilized to charge the UPS battery and to provide power to the Inverter. The Inverter converts
the DC power to clean AC power to supply the critical load.
The conversion - inversion process eliminates any voltage transients or fluctuations existing in
the input power before it reaches the critical load.
The power drawn by the critical load is equally shared between all UPS units whenever the
system is in Parallel Operation (refer to Figure 3.4 that shows a sample of the Parallel
Operation System Configuration).
9900B SERIES UPS
OWNERS / TECHNICAL MANUAL
UPS Module
CONVERTER /
CHARGER
CB1
Battery
Cabinet
External
BATTERY
MITSUBISHI ELECTRIC 9900B SERIES UPS
52S
CB3
Static Transfer
Switch
INVERTER
52C
CB2
Page Number:
1-8
Output
Power Flow
Not in Use