Modifications reserved
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OPM_LPS_3UO_50K_60K_1US_V010.doc
Operating Manual
LP 33U Series 30 & 40 kVA
Manual bypass
operation
The
manual bypass
circuit consisting of
Q1
and
Q2
manual switches permits the transfer of the
load
directly to the
utility
without interruption,
leaving the UPS galvanically separated from the
output
load
.
This type of operation is normally used when the
UPS system must be completely turned off for
maintenance or reparation.
Fig. 4.2-5 Energy flow in manual bypass operation
Utility
failure operation
In the event of a
utility
power failure, the
rectifier
and the
battery-charger
turn OFF,
while the
inverter
continues to supply the
load
without interruption using the energy stored in
the
battery
.
During the
battery
discharge, the LCD screen
displays the remaining autonomy, based on the
battery
capacity and the applied
load
.
Fig. 4.2-6 Energy flow during utility failure operation
In the event of an extended utility failure, before the
battery
is fully discharged, the alarm “
stop
operation
” warns the user that the UPS will start the shutdown procedures when the indicated time
expired (normally 3 minutes).
In case of parallel system
With parallel system for power capacity
:
•
With the
bypass utility power available
as the warning “battery low” occurs on one unit, after
timeout (selectable) the load is transferred to utility.
•
With
missing bypass utility power
as the warning occurs on one unit, the system starts the
timeout (selectable) of “Stop operation” and then the output load shuts down.
With redundant parallel system
:
•
As the warning battery low occurs on one unit unnecessary to support the present load, after
timeout (selectable) this unit shuts down and the load is shared between the other units.
As the warning occurs on one unit necessary to support the present load, the system starts the
timeout (selectable) of “stop operation” and then the output load shuts down.