The UPS provides uninterrupted power to a critical load, being supplied either by mains or by batteries via the internal inverter. In the automated function the supply of the priority input (mains) is connected to the load. If the internal static switch detects deviation from tolerance, it will transfer the load to the non-priority input (inverter).
When the supply of the priority input has returned to be within parameters of voltage and frequency, the static switch reverses this selection.
For adapting the UPS to different requirements, the priority for mains or inverter operation can be selected externally via switch on the rear side of the UPS. The UPS can also be inhibited either via opto-coupler or
via external relay contact for disconnecting the load. LEDs indicate the mode of operation and / or the status of alarms. A potential-free relay contact is given for common alarm.
Optionally, a manual bypass switch can be provided for connecting the load directly to the mains while disconnecting the UPS or the batteries in case of maintenance. For maximum flexibility the batteries (external)
can be specified according to the requirements on site and a suitable battery charger (external) can be chosen from the Schaefer product range.