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1.1.5
Backfeed protection
The UPS is provided with a redundant device to prevent voltage backfeed on the input line due to an internal
fault. This protection device works by switching off the inverter when detecting a fault current that cause voltage
backfeed on the bypass line during operation from the inverter. If the fault occurs when the UPS is operating
from the battery the load will not be powered.
The control logic allows the function of the relay to be configured, for example for the backfeed alarm, and then
the dry contact can be used to control the triggering of a switch located on the UPS input.
1.1.6
Emergency Power Off device (EPO)
The UPS has an EPO (Emergency Power Off) function.
In the event of an emergency using this function the UPS shuts down the rectifier, inverter, static switch and
completely disconnects the power to the load
The Output circuit of the UPS should not be considered safe, unless the UPS is Off and the input power source to
the UPS has been removed by opening the input disconnect devices which are external to the UPS, including the
battery.
This function can be activated by pushbutton (under a hinged clear plastic cover) on the control panel or by a
remote contact. This pushbutton must be depressed and held down until the UPS shuts down.
To connect an external EPO to the remote contact follow this procedure.
a - EPO terminal board located on the UPS
b - EPO switch (not provided).
On the UPS, the jumper on the EPO terminals must be removed, and the wires from the auxiliary contact of the
pushbutton must be connected in place of the jumper.
The pushbutton in the rest position have contacts N.C., when it is pressed the pushbutton contacts are open.
UPS
a
b
