Signals - ABB 615 series Technical Manual

1MAC059074-MB A
4.7.3.6
4.7.3.7
Table 616: 21G Group settings (Basic)
Parameter Values (Range)
Percentage reach 1...6000
Trip delay time 40...200000
615 series ANSI
Technical Manual
Function blocking guidelines
The operation of the underimpedance protection must be restrained if the voltage in one
or more phases suddenly drops close to zero without any significant change in the current
observed at the same time. This situation is considered as a fuse failure or a miniature
circuit breaker operation in the voltage transformer secondary circuit. The voltage drop
could cause an unwanted operation of the function block since the calculated impedance
could fall below the set operating limit even if there is no actual fault in the primary
system.
The blocking operation is provided by an external function block, the fuse failure
supervision 60, whose output is connected to the BLOCK input of 21G.

Signals

Table 614: 21G Input signals
Name Type
I_A SIGNAL
I_B SIGNAL
I_C SIGNAL
I SIGNAL
1
V_A_AB SIGNAL
V_B_BC SIGNAL
V_C_CA SIGNAL
V SIGNAL
1
BLOCK BOOLEAN
Table 615: 21G Output signals
Name Type
TRIP BOOLEAN
PICKUP BOOLEAN
Settings
Unit Step
%Zn 1
ms 10
Default Description
0 Phase A current
0 Phase B current
0 Phase C current
0 Positive sequence current
0 Phase-to-ground voltage A or phase-to-phase voltage
AB
0 Phase-to-ground voltage B or phase-to-phase voltage
BC
0 Phase-to-ground voltage C or phase-to-phase voltage
CA
0 Positive phase sequence voltage
0=False Block signal for activating the blocking mode
Description
Trip
Pickup
Default Description
7 Radius of the origin centric circle
200 Trip delay time
Section 4
Protection functions
715