CBC EA 900RT 1KVAS User Manual page 17

TRUE ON LINE UPS
APPENDIX :
Parallel operation (6KVA and 10KVA)
1. Brief introduction of the redundancy
N+X is currently the most reliable power supply structure. N represents the minimum UPS
number that the total load needs; X represents the redundant UPS number, i.e. The fault UPS
number that the system can handle simultaneously. The bigger the X is, the higher reliability
of the power system is. For occasions where reliability is highly depended on, N+X is the
optimal mode.
As long as the UPS is equipped with parallel cables, up to 3 UPSs can be connected in parallel
to realize output power sharing and power redundancy.
2. Parallel installation
1) Users need to opt a standard 25-pin communication cable, which should have 25 cores,
correspondings stitches and shield, as the UPS parallel cable. The length of the parallel cable
is appropriate to be less than 3m.
2) Strictly follow the stand-alone wiring requirement to perform the input wiring of each UPS.
3) Connect the output wires of each UPS to an output breaker panel, disconnect the jumper
on JP1 and JP2 of the terminal block first, and connect each output breaker to a main output
breaker and then to the loads.
The requirement of the output wiring is as follows:
When the distance between the UPS in parallel and the breaker panel is less than 20 meters,
the difference between the wires of input & output is required to be less than 20%.
When the distance between the UPS in parallel and the breaker panel is greater than 20
meters, the difference between the wires of input & output is required to be less than 10%.
3. Operation and maintenance
1) To perform the general operation, follow the stand-alone operating requirement;
2) Startup: The units transfer to INV mode simultaneously as they start up sequentially
in utility power mode;
Shutdown: the units shut down sequentially in INV mode. When the last one completes the
shutdown action, each unit will shut down the inverter simultaneously and transfer to bypass
mode.
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Input Switch Board
Output Switch Board
Load Load Load
TRUE ON LINE UPS
Load
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