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3. Installation and Setup
3.6 UPS Installation for Parallel Systems
Warning:
•
The input harmonic current distortion will be between 3% and 4.5% in parallel UPS operations.
• One parallel kit is needed for every two UPS systems.
3.6.1 Input and Output Wiring
1. When installing the parallel system, the length of input wires (R, S, T, N) in one UPS must be equal to the input wires of the other UPS.
Likewise, the length of output wires (R, S, T, N) must also be in equal length. If not, it will cause unbalance current on the output load.
Figure 3.6 Single Input Wiring In Parallel System
Maintenance
Breaker
Output
Breaker
Input
Breaker
AC I/P
1
Parallel Cable
Load
Input 2
Input 1
Output
Static Switch
UPS Module
Bat Module
Bat Module
UPS Module
RECT
Inv
Charger
Charger
Maintenance
Breaker
Static Switch
Output
Breaker
Input
Breaker
Input 2
Input 1
Output
UPS Module
Bat Module
Bat Module
UPS Module
RECT
Inv
Charger
Charger