ABB RD2 Handbuch Seite 8

On-panel controls
1- Green LED "ON": power ON
2- Red led "TRIP": alarm status the connection between the
toroidal transformer and the differential relay is continuously
controlled by the latter - if the connection is interrupted, the
differential relay goes into "alarm" status.
3- The "TEST" push-button simulates a fault inside the differential
relay: when the button is pressed, the differential relay must
changeover to alarm status.
4- The "RESET" push-button returns the differential relay to its initial
"non alarm" status.
5- To select tripping steps I
6- To select tripping steps in seconds.
∆
1
ON
5
n.
3
TEST TRIP
RESET
8
2
4
6