ABB 615 series Technical Manual page 668

Section 4
Protection functions
662
Settings
Voltage level 4
Recovery time 4
Voltage level 5
Recovery time 5
It is necessary that the last active Voltage level X setting is set greater than
or equal to Voltage pickup value. Settings are not accepted if the last active
Voltage level X setting is not set greater than or equal to Voltage pickup
value.
Figure 331 describes an example of operation of 27RT protection function set to operate
with Num of pickup phases set to "Exactly 2 of 3" and Voltage selection as "Lowest Ph-
to-Ph" voltage.
Voltage
xVn
Vn
Voltage pickup value
PICKUP
TRIP
GUID-532E4687-DF59-4DA7-9F93-6186FBA14C64 V1 EN
Figure 331: Typical example of operation of 27RT function
Activation of the BLOCK input resets the timers and deactivates the function outputs.
Curve A
-
-
-
-
Num of start phases = Exactly 2 of 3
Voltage selection = Lowest Ph-to-Ph
V_BC
V_AB
PICKUP
TRIP
V_CA
100ms
1MAC059074-MB A
Curve B
0.9 · Un
1500 ms
0.9 · Un
3000 ms
Time in ms
615 series ANSI
Technical Manual