MGE UPS Systems Galaxy PW Power Supply User Manual


 
4
system description
(see figure 1)
a rectifier/charger module (A) converts
3-phase AC power from the normal AC
source supply (1) into DC power for the
normal inverter input and float charges or
recharges the battery;
a battery unit (D) provides backup
power for the inverter in the event of a
voltage drop or a normal AC source fail-
ure;
an inverter module (B) converts the DC
power supplied by the rectifier/charger
module or the battery unit into 3-phase AC
power for the load;
a static bypass module (C) ensures the
instantaneous transfer of the load to the
bypass AC source input in the event of an
inverter shutdown (initiated by the user or
by a protective device) or a sudden over-
load;
a maintenance bypass isolates the UPS
for maintenance and transfers the load to
bypass AC source input without interrupt-
ing the supply of power. The maintenance
bypass is made up of three manual
switches (Q3BP, Q4S and Q5N).
Note
the normal AC input and the bypass AC
input have different functions and,
depending on the installation, may be pro-
tected differently upstream and/or come
from different sources.
when increased power is required, sev-
eral Galaxy PW™ units may be connect-
ed in parallel (up to four). In this configura-
tion, an "isolation" function is added for
the UPS system as a whole for mainte-
nance purposes, without interrupting the
supply of power to the load.
The system may also include:
Isolation or auto transformers on both
input and output.
2 CB or 3 CB maintenance bypass
different remote control, indication and
display systems.
Introduction
Fig. 1 *The Fuse is to protect against catastrophic rectifier/inverter
semiconductor failure.
Schematic diagram of the Galaxy PW™ system
maintenance bypass:
Q3BP
inverter (B):
DC to AC
power
isolation:
Q4S
isolation and
protection:
Q5N
rectifier/
charger (A):
AC to DC
power
QF1: isolation
and protection
normal
AC input
load
battery (D):
backup power
static bypass (C):
bypass
AC input
Q1
isolation
and
protection
(1)
(2)
harmonic
fliter
*FUSE
*FUSE
Galaxy PW
TM
100 to 225 kVA