Eaton E Series DX - Parallel UPS Installation

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3.5 Parallel UPS installation
1. Redundancy introduction
N+X is currently the most reliable power supply structure, in which N indicates
the minimum UPS number required for the total load and X is the redundant
UPS number, namely, the malfunctioning UPS number that the system can
simultaneously bear. The larger X is, the higher the reliability of the system.
2. EDX Series UPS is capable of direct parallel connection, which only requires
the parallel connection wires (optional) for 2 to 6 sets of UPS in parallel
connection in order to realize power redundancy (N+X). Ventilation spacing
between UPS units should be a minimum of 10cm, input wiring for each set
of UPS should follow the requirements for that of single unit. Each UPS input/
output should be connected to the same input switchboard, from which wires are
distributed for load as illustrated in the following gure:
Remark:
1）Common battery pack can be used in parallel configurations; each battery pack
should be of the same model and the same batch from the same manufacturer.
2) Requirement of output wiring length:
① When the cables from the output terminal of each set of UPS to the output
switchboard are less than 20m, cable length difference should be less than 20%;
② When the cables from the output terminal o
f each set of UPS to the output
switchboard are longer than 20m, cable length difference should be less than 10%.