U.6.10
SEL-421 Relay User’s Guide Date Code 20090715
Testing and Troubleshooting
Relay Test Connections
Figure 6.3 Test Connections Using Two Current Sources for Phase-to-Phase,
Phase-to-Ground, and Two-Phase-to-Ground Faults
Three-Phase
Voltage and Current
Test Sources
IA
VB
IB
VC
IC
VA
IAW
Z01 Z02 Z03 Z04 Z05 Z06
Z13 Z14 Z15 Z16 Z17 Z18
IBW ICW
VAY VBY VCY
Relay Rear-Panel Secondary
Voltage and Current Inputs
N
N
N
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