GE SG SERIES 20 User Manual
Page 16
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GE
OPM_SGS_USM_10K_40K_0US_V010.doc
16/88 Operating
Manual
SG Series 10, 20, 30 & 40 kVA
3.4
RECTIFIERS PARALLELED ON THE SAME BATTERY
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 engineer from 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 - see Fig 4.12-1), 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. 3.4-1 Diagram RPA system with Rectifiers on Common Battery
1 –
2 –
3 –
4 –
5 –
6 –
7 –
8 –
Rectifier
Inverter
Automatic Bypass
Manual Bypass
Mains Power
Load Bus Bar
External Battery Fuse
Battery
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 must be completely shut
down.
•
The AC Rectifiers input power (5) 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 / MCB (7) 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 / MCB on the Battery line (7).
•
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 7.1).
•
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).