Sel 421 - Figure 6.6 Test Connections Using a Single Current Source for a Phase-To-Phase Fault

U.6.13
Date Code 20090715 User’s Guide SEL-421 Relay
Testing and Troubleshooting
Test Methods
Figure 6.6 Test Connections Using a Single Current Source for a
Phase-to-Phase Fault
Test Methods
Use the following methods to conveniently test the pickup and dropout of
relay elements and other relay functions:
➤ Target indications (element pickup/dropout)
➤ Control output closures
➤ SER reports
The tests and procedures in the following subsections are for 5 A relays. Scale
values appropriately for 1 A relays.
Once you have completed a test, return the relay settings that you modified for
the test to default or operational values.
Testing With Targets
Use the communications port TAR command or the front panel to display the
state of relay elements, control inputs, and control outputs. Viewing a change
in relay element (Relay Word bit) status is a good way to verify the pickup
settings you have entered for protection elements.
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
Courtesy of NationalSwitchgear.com