Sel SEL-421 - Configuration-Independent Current Inputs; ESS:= 2, Current and Voltage Source Selection; ESS:= 3, Double Circuit Breaker Configuration

R.1.10
SEL-421 Relay Reference Manual Date Code 20111215
Protection Functions
Current and Voltage Source Selection
ESS := 3, Double Circuit Breaker
Configuration—Independent Current Inputs
Set ESS to 3 for circuit breaker-and-a-half applications using independent
current sources. Figure 1.7 illustrates this application along with the
corresponding current and voltage sources. This selection provides
independent circuit breaker failure protection for Circuit Breaker 1 and Circuit
Breaker 2.
Figure 1.7 ESS := 3, Double Circuit Breaker Configuration
Table 1.7 ESS := 2, Current and Voltage Source Selection
Setting Description Entry Comments
NUMBK Number of Circuit Breakers in Scheme (1, 2) 1
LINEI Line Current Source (IW) IW Automatic
ALINEI Alternate Line Current Source (IX, NA) NA
ALTI Alternate Current Source (SEL
OGIC Equation) NA Hidden
a
a
Hidden when preceding setting is NA.
BK1I Breaker 1 Current Source (IX) IX Automatic
BK2I Breaker 2 Current Source (NA) NA Hidden
IPOL Polarizing Current (NA) NA Automatic
ALINEV Alternate Line Voltage Source (VZ, NA) NA
ALTV Alternate Voltage Source (SEL
OGIC Equation) NA Hidden
Analog Input
IW+IX
IW
IX
VY
VAZ
VBZ
Function
Line protection
CB1 protection
CB2 protection
Line protection
Synchronism check Circuit Breaker 1
Synchronism check Circuit Breaker 2
3
3
1 1
Busbar 1 Busbar 2
1
SEL-421
Breaker 1 Breaker 2 IW
IX
VY
VAZ
VBZ
Line 1
Line 2