Modifications reserved
Page 16/103
OPM_LPS_33E_60K_M12_2GB_V010.doc
Operating Manual
LP 33 Series 60-80-100-120 kVA / S2
Automatic bypass
operation
In
VFI
(Voltage Frequency Independent)
operation mode, the
load
is permanently
supplied by the i
nverter
but, in case of trouble
on the
inverter
, or when overload or short-
circuit on the output occur, if the
mains
voltage do not exceed the admitted tolerances,
the
load
is instantly transferred to the
mains
through the
automatic bypass
, taking
advantage of the higher short circuit power.
Fig. 4.2-3 Energy flow in automatic bypass operation
When the
inverter
recovers, the
load
will be re-transferred automatically to the
inverter
.
In case of Parallel System
Each unit has its own bypass.
All the bypasses in the system work together, their control being managed in the same manner by
all units.
The units are continuously exchanging information before taking such decision.
In case the inverter of one unit fails, its bypass remains operating.
It is excluded only if the unit is separated from the common bus by opening its output switch Q1.
Mains
recovery operation
As soon as the
mains
recovers, the
rectifier
starts up automatically supplying the
inverter
and the
battery-charger
recharges the
battery
.
In case the
inverter
has been shut down
following a complete discharge of the
battery
,
when the
mains
recovers the system start up
automatically.
Fig. 4.2-4 Energy flow at mains recovery operation
When the energy stored in the
battery
is sufficient to ensure a minimum time of operation with the
actual load, in case of a future
mains
failure, the
load
will be retransfered to
inverter
(if selected
VFI
Mode
).
In case of Parallel System
When the AC input power recovers,
the rectifiers will start up sequentially
according to their
number in the Parallel System
in order to avoid an initial inrush current
.
The
inverters will start up automatically
, but only when the battery has recharged enough for a
minimum runtime
with the present load.
When enough inverters to supply the load have been restarted,
the load will be transferred from the
automatic bypass back to the inverter bus-bars
.
