GE LP 33 Power Supply User Manual


 
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OPM_LPS_3UO_30K_40K_0US_V010.doc Operating Manual LP 33 Series 30 & 40 kVA
3.4 UPS PARALLELED ON THE SAME BATTERY
NOTE !
A parallel system with a Common Battery for two or more UPS, requires a particular
installation and adequate setting of some parameters, (accessible only through
password), and can therefore only be done by a qualified GE engineer.
Usually each UPS Unit runs with its own Battery.
In case of parallel units running with a Common Battery (max. 4 UPS - see Fig. 3.4-1), the sharing circuit
between the individual UPS 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 UPS 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 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 mandatory to install the fuses / MCB (7) on each line connecting the Rectifiers to the common
Battery for maintenance / safety reasons (see Section 4.7.2).
In case a unit must be powered down for maintenance, switch-OFF the concerned unit before open
the DC fuses / MCB on the Battery line (7).
If an emergency generator set supplies the UPS, and the free contact “Generator ON” is connected
to the Customer Interface, connect a separate NO free contact on each parallel unit.
Do not connect the temperature sensor for automatic battery floating voltage compensation.
Do not enable the function Boost charge.