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UPS theory of operation

Unitary UPS

The unitary MGETM GalaxyTM 6000
UPSs are made up of five modular
sub-assemblies:
rectifier-charger;
battery;
three-phase inverter;
static switch;
maintenance bypass.
The load and Mains 2 operate at 50
or 60 Hz.

Mains 1 power up

the inverter receives power from
the rectifier-charger and supplies
power to the load. There is no
direct connection between Mains
and load;
the battery is charged or the
charge maintained.
Mains 1
rectifier-
charger
battery
inverter
load
static by-pass switch
Mains 2

Mains 1 power down

the inverter receives power from
the battery and supplies power to
the load;
the battery discharges.
Mains 1
rectifier-
charger
battery
inverter
load
static by-pass switch
Mains 2

Major overload

Mains 2 supplies power to the
load via the static switch;
the inverter is shut down;
the inverter starts-up
automatically as soon as overload
is removed;
power is transferred without
affecting the load.
Mains 1
rectifier-
charger
battery
inverter
load
static by-pass switch
Mains 2

Maintenance

Mains 2 supplies power to the
load via the maintenance bypass;
the rectifier-charger and inverter
are shut down and disconnected
from all sources of power.
Q1 Q5N
QF1
Q3BP
Q4S
Mains 1
rectifier-
charger
battery
inverter
load
static by-pass switch
Mains 2