Emerson 480V user manual Parallel System Start Up

Operating Instructions

9.10Parallel System Start Up

1.Start each UPS normally as described in 9.2 - UPS Startup

2.Turn on the inverter of each UPS module one at a time.

3.Apply the load after the last UPS module transfers to inverter. The total load can be determined through the LCD of either UPS.

4.Verify the load rate of each UPS module. If the load rates are roughly the same, then the parallel system may be assumed to be operating normally.

NOTE

If one module cannot transfer to inverter mode long after its inverter is on, its output connection may not be good or its output phase rotation may not be coincident with other modules. At this time, the LCD for the UPS module will display “inverter asynchronous” and the inverter indicator will flash continuously. If either UPS module makes abnormal noise after it transfers to inverter, its parallel cables may be incorrectly connected.

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