11-8 Testing and Troubleshooting Date Code 20010731
SEL-352-1, -2 Instruction Manual
Figure 11.4: Test Connections With Three-Phase Voltage and Two-
Phase Current Sources
Step 11.
Purpose: Connect simulated power system secondary current sources to the relay.
Method: Turn power off to the relay and connect current sources. If three current
sources are available, connect them to the relay in four-wire wye, as
shown in Figure 11.3. If only two current sources are available, wye-
connect the sources as shown in Figure 11.4 to generate balanced
positive-sequence currents:
a. Connect the A-phase and B-phase current sources to the dotted A and
B current input terminals.
b. Connect both undotted A and B current input terminals to the undotted
C current input terminal.
c. Connect the dotted C current input terminal to both the A and B
current source returns.
Set the current sources to deliver one ampere at the same angle as their
corresponding phase voltages.
Step 12.
Purpose: Verify correct current levels.
Method: Turn relay power on, and use the METER command to measure the
currents applied in Step 11. With applied currents of one ampere per
phase and a current transformer ratio of 600:1 (SHO CTR <ENTER>
displays the CT ratio, <CTRL> X cancels scrolling), the displayed
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