Modifications reserved
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OPM_SGS_USM_M75_M75_2US_V010.doc
User Manual
SG Series 750 UL S2 & SG Series 750 T12 UL S2
4.4 RECTIFIERS PARALLELED ON THE SAME BATTERY
NOTE !
A parallel system with a
Common Battery
for two or more
Rectifiers
, requires
a particular installation and adequate setting of some parameters,
(accessible only through password), and can therefore only be done by a
QUALIFIED SERVICE ENGINEER GE
.
Usually each
Rectifier-Inverter Unit
runs with its own
Battery
.
In case of parallel units are running with a
Common Battery
(max. 4 UPS - in
SG Series 750
&
SG Series
750 T12
we already have two rectifiers in parallel - see
Fig 4.4-1)
, the sharing circuit between individual
Rectifier
is integrated in the communication bus of the system in order to assure an equal sharing of the
Rectifiers
output currents.
Fig. 4.4-1 Diagram RPA system with Rectifiers on Common Battery
1 –
2 –
3 –
4 –
Utility input
External Battery Fuse
Battery
Load Bus Bar
Pay attention to the following recommendations:
•
The units delivered for this functioning mode needs a special parameters setting, so they must be
prepared in advance before the installation.
•
The installation must be performed only with the UPS system completely shut down.
•
The AC
Rectifiers
input power (1) must be the same, with clockwise phase rotation for each unit.
•
Each
Rectifier
must be set for the same floating DC voltage and the same
Battery
current limitation.
•
It is recommended to install the fuses / MCCB (2) on each line connecting the
Rectifiers
to the
common
Battery
for maintenance / safety reasons.
•
In case one must be powered down for maintenance, switch-OFF the concerned unit before open
the DC fuses / MCCB on the
Battery
line (2).
•
It is recommended to connect an external NO free contact
“Battery Fuses”
to the UPS and to enable
the function by setting the parameter (see
Section 4.1
of the
“Installation Guide”)
.
•
If an emergency generator set supply the UPS, and the free contact
“Generator ON”
is connected to
the Customer interface, connect a separate NO free contact on each parallel unit.
•
The parameters enabling the
Battery test
, both manual and automatic, must be set in the same
mode on all the units having the
Rectifiers
on
Common Battery
.
•
Do not connect the temperature sensor for automatic
battery floating voltage
compensation.
•
Do not enable the function
Boost charge
(parameter 87).