UPS OPERATING INSTRUCTIONSEaton 9390 UPS (100–160 kVA) Installation and Operation Manual 164201604 Rev E www.eaton.com/powerquality 9-139.2.2 Starting the Parallel System in Bypass ModeIf the inverter output of the UPMs is not available and the critical load needs to beenergized:C A U T I O NIn Bypass mode, the critical load is not protected from commercial power interruptions and abnormalities.1. Close all UPM input feeder circuit breakers.2. If the UPMs are dual feed, close all UPM Bypass input feeder circuit breakers.3. Observe all UPM control panel displays becoming active, indicating logic power.4. Press the CONTROLS pushbutton on the main menu bar of any UPM. The SystemControls screen appears on each UPM.5. On the System Controls screen of each UPM, the power module (PM) statusshould indicate SHUTDOWN.6. Press the BYPASS pushbutton on the System Controls menu bar of any UPM.The critical load is immediately supplied by the bypass source, in Bypass mode.7. The UPMs are now operating in Bypass mode and the BYPASS status indicatoron each UPM is illuminated.9.2.3 Transfer Parallel System from Normal to Bypass ModeTo transfer the critical load to Bypass mode:C A U T I O NIn Bypass mode, the critical load is not protected from commercial power interruptions and abnormalities.1. Press the CONTROLS pushbutton on the main menu bar on any UPM. The SystemControls screen appears.2. Press the BYPASS pushbutton on the System Controls menu bar of any UPM.The UPMs transfer to Bypass mode and the critical load is immediately suppliedby the bypass source. If the bypass source is not available, the power processorremains on and an alarm sounds.3. The UPMs are now operating in Bypass mode and the BYPASS status indicatoron each UPM is illuminated.The power module (PM) status indicates READY on each UPM. The system isnow on bypass and the UPM power processors remain on.W A R N I N GPower is present inside the UPM cabinets.
