20 - 80 kVA parallel UPS system
User’s and Installation Manual
1018390
Revision C
20
6.4 Parallel operation
UPS modules have a cable connection between them to inform about the phase synchronism
of the bypass voltages. It is needed in order to transfer the critical load back from the bypass
line to inverters at the same time. The transfer from inverters to bypass functions without
the data bus connection in case of overload situation.
A cable entry is located on rear panel beside the power cable entry. Route the cables behind
the narrow front panel to the circuit board A5: X3/X4. The cable is leaving from the terminal
X4 on the circuit board A5 and connected to the terminal X3 in the next UPS module. See
the figure for correct wiring of the communication bus.
Figure 11.
Ring topology of the cable connection between UPS modules.
The shield of the parallel information cable has to be grounded to the UPS ground from the
one end of the cable only. Connect the cable shield to the grounding screw of the RFI board
(20-30 kVA) or the PCB A12 assembly plate (40-80 kVA).
6.5 Battery cables
Located behind the door, the external battery connection (+, -, N and PE) is used with BAT
D, BAT E and BAT F cabinets.
Each shipment of external battery cabinets includes 16 mm
2
power cables for the electrical
installation. The electrical installation of external cabinets should be done according to
appropriate wiring diagrams.
External battery cabinets also have a temperature measurement sensor that is located under
the roof. The temperature information must be linked together when installing several
external cabinets. The control cable of temperature measurement sensor should be
connected to the male terminal X6 in the UPS module
Battery configurations with 20-30 kVA UPS modules
An optional battery breaker F4 (p/n: 1014196) is needed with each 20-30 kVA UPS modules
if external battery cabinets are used. The breaker includes a four-part X9 plug terminal that
is connected to the X8 plug terminal of the UPS module. Be careful with the X8-X9 terminal
because it’s connected to the internal battery bank and contains high DC voltage.
Power cables should be connected directly to the terminals of battery breaker F4. See the
battery wiring diagrams and chapter ‘Location of terminals’ for the correct power cable
connections.