Schweitzer Engineering Laboratories SEL-749M - Table 10.4 Current Unbalance Measuring Accuracy; Figure 10.5 Wye Voltage Source Connections

10.8
SEL-749M Relay Instruction Manual Date Code 20080918
Testing and Troubleshooting
Commissioning Tests
Power and Power Factor Measuring Accuracy
Wye-Connected Voltages
Perform the following steps to test wye-connected voltages:
Step 1. Connect the current source to the relay, as shown in
Figure 10.4.
Step 2. Connect the voltage source to the relay, as shown in
Figure 10.5. Make sure that DELTA_Y := Wye.
Figure 10.5 Wye Voltage Source Connections
Step 3. Using the front-panel SET/SHOW or the serial port SHOW
command, record the CTR1, PTR, and PHROT setting values.
Step 4. Apply the current and voltage quantities shown in Column 1 of
Table 10.5.
Values are given for PHROT := ABC and PHROT := ACB.
Step 5. Use the front-panel
METER function or the serial port MET
command to verify the results.
Table 10.4 Current Unbalance Measuring Accuracy
|I| Applied (A secondary) Expected Reading (%) Actual Reading (%)
|IA| = 0.9 • FLA1/CTR1 7%
|IB| = FLA1/CTR1
|IC| = FLA1/CTR1
|IA| = 0.75 • FLA1/CTR1 17%
|IB| = FLA1/CTR1
|IC| = FLA1/CTR1
|IA| = FLA1/CTR1 12%
|IB| = 1.2 • FLA1/CTR1
|IC| = 1.2 • FLA1/CTR1
|IA| = 0.9 • FLA1/CTR1 13%
|IB| = 1.1 • FLA1/CTR1
|IC| = 1.1 • FLA1/CTR1
SEL-749M
E01
E02
E03
E04
Voltage
Test
Source
VA
VB
VC
VN
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