Schweitzer Engineering Laboratories SEL-352-1 - Meter Test

11-12 Testing and Troubleshooting Date Code 20010731
SEL-352-1, -2 Instruction Manual
The relay computes internal settings and compares them against fixed limits. If all
settings fall within acceptable ranges, the ALARM contact closes momentarily
(unless an alarm condition already exists) as the new settings are enabled.
4. Use the SHOWSET command to inspect the settings and verify that the change
you made in Step 2 was accepted. Type SHO <ENTER>.
5. Use SET and SHOWSET again to restore the initial values and check the
settings.
METER TEST
Purpose: Verify the magnitude accuracy. This test uses two or three current and three voltage
sources, but it only requires a single voltage and current source.
Method: 1. Connect simulated power system secondary current and voltage. See Figure 11.3
and Figure 11.4 for the test connections.
2. Apply a phase-to-neutral voltage of 50 Vac for each voltage input and a current of
1 A for each current input. The phase angle of the voltage and current sources
should all be set to 0.
3. Use the METER command to inspect measured voltages, currents, and power.
Voltages VAX, VBX, VCX, VAY, VBY, and VCY should equal the applied
voltage times the potential transformer ratio setting. With the Example 500 kV
Line settings, you should obtain:
VA = VB = VC = (50 V)(4300) = 215 kV
AB, BC, and CA voltages for VX and VY should read less than 1.5 kV because
each phase-to-neutral voltage is at the same angle.
Similarly, currents IA, IB, and IC should equal the applied current times the
current transformer ratio. With the Example 500 kV Line settings, you should
obtain:
IA = IB = IC = (1 A)(600) = 600 A
Difference currents IAB, IBC, and ICA should be less than 20 A. The power
reading, P (MW), should read:
P = (VA)(IA) + (VB)(IB) + (VC)(IC) = 387 MW.
The reactive power reading Q (MVAR) should be less than 20 MVAR.
Simultaneous application of voltage and current to the relay could cause the
breaker resistor thermal elements to operate. Use the HEAT R command to reset
the energy levels of the resistor thermal models after completing this test.