Eaton 93E MK2 - Figure 5-2. Path of Current through the UPS in Standard Normal Mode

If the utility AC power is interrupted or is out of specification, the UPS automatically switches to Battery
mode to support the critical load without interruption. When utility power returns, the UPS returns to
Normal
mode.
Bypass Input
Bypass Switch (Optional Dual Input)
Static
Rectifier
Input
Input Switch
Input
Relay
Rectifier
Switch
Inverter
Output
Relay
Output
Battery
Converter
Switch
Relay
Closed
Open
Battery
Relay
Battery
Main Power Flow
Trickle Current
Energized
De-Energized
Figure 5-2. Path of Current Through the UPS in standard Normal Mode
If the UPS
becomes overloaded or unavailable, the UPS switches to Bypass mode. The UPS
automatically returns to Normal mode when the overload condition is cleared and system operation is
restored within specified limits.
If the UPS
suffers an internal failure, it switches automatically to Bypass mode and remains in that mode
until
the failure is corrected and the UPS is back in ser vice.
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Eaton 93E MK2 UPS (10-40kVA, 380/400/415V) Installation and Operation