Note: To preserve bearing life, the flywheel should be stopped before the power is removed from the system.
- Turn the SIO cabinet key switch to the Bypass position.
- Confirm that the system is in "Bypass" by observing the "System Diagram/Overview" screen.
Note: Continuing with the procedure will disconnect the critical load from the output of the UPS.
- Disconnect the facility load circuits from the output.
- Remove facility power from the input.
- Remove facility power from the "Bypass" input if the installation is a dual input system.
- Allow the capacitor banks to discharge for approximately 5 minutes to dissipate any residual energy in the bus and armature leads.
Note: When the flywheel is spinning, the bus and armature leads are energized.
Using the UPS Emergency Power Off (EPO) Button
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When the EPO button is used, the UPS system is shut down. Power is not supplied to the load. However, voltage is still present on the input terminals. The critical load will lose power unless the customer has provided an external bypass. |
A UPS emergency power off is initiated by pressing the covered, red EPO button. The EPO button is on the SIO cabinet user interface panel. The button is protected by a clear plastic shield to prevent accidental use. In an emergency, you can press the button to control the UPS output.
- Raise the clear plastic shield covering the red EPO button.
- Press the EPO button.
The input and output bypass switches open. The switches can be heard opening. To restart the UPS after pressing the EPO button, use the following procedure. Refer to Systems Operation, Test and Adjust, UENR4695, "Resetting the UPS System after an Emergency Shutdown".
Resetting the UPS System after Emergency Shutdown
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Do not attempt to restart the system after an emergency shutdown until the cause of the emergency has been identified and corrected. |
To reset the system after using the EPO button, first perform the following steps.
- Move the SIO cabinet user interface panel key switch from the Normal position to the Bypass position.
- Press the EPO button. The button returns to the unpressed position.
- The UPS is now reset.
Note: If the flywheel is spinning, the utility inverter and field coil driver will turn back on to unload the flywheel.
Remote Emergency Power Off (REPO) Button (Optional)
The REPO button is optional. The REPO button functions the same as the EPO button.