BE1-951
Testing and Maintenance
13-9
Auxiliary Voltage Input Verification-VX and VX 3rd (Fundamental and Third Harmonic)
Step 1 Connect relay terminals C17 (polarity) and C18 to a 60 Hertz ac voltage source.
Step 2 Apply the voltage values listed in Table 13-5 and verify voltage-measuring accuracy by
transmitting the M-V command to the relay. HMI Screens 3.3, VX can also be monitored to verify
voltage measurements.
Step 3 Connect relay terminals C17 (polarity) and C18 to a 180 Hertz (third harmonic) ac voltage
source.
Step 4 Apply the voltage values listed in Table 13-5 and verify voltage-measuring accuracy by
transmitting the M command to the relay. HMI Screens 3.3, VX can also be monitored to verify
voltage measurements.
Table 13-5. Aux Voltage Circuit Verification VX & VX 3rd Values
Applied Voltage
Measured Voltage
Lower Limit
Upper Limit
5 volts
4.95 V
5.05
20 volts
19.8 V
20.2 V
60 volts
59.4 V
60.6 V
80volts
79.2 V
80.8 V
120 volts
118.8 V
121.2 V
Line and Bus Angle, Frequency, and Slip Verification
Step 1 Connect relay terminals C13 (polarity) and C16 (A to Neutral of the three-phase voltage input) to
a 60 Hertz ac voltage source (line voltage).
Step 2 Connect relay terminals C17 (polarity) and C18 (auxiliary voltage input) to a second 60 Hertz ac
voltage source (bus voltage).
Step 3 Apply 115 volts at 0 degrees and 60Hertz to both sources. Verify the measuring accuracy of the
line and bus frequency, angle between the two voltages, and slip frequency by transmitting the
M command to the relay. HMI Screens 3.10 and 3.11 can also be monitored to verify the
measurements.
Step 4 Vary the angle of the line voltage and verify the measured angle as in Step 3. Polarity of the
angle measurement is relative to the angle of the line voltage. That is, if the line voltage lags the
bus voltage by 30 degrees, the sign of the angle will be negative or -30 degrees. When the line
voltage leads, the angle has no sign and is assumed to be positive.
Step 5 Return the line voltage angle to 0 degrees. Vary the frequency of the line voltage, and verify the
measured slip as in step 3 (Note that the angle shown on HMI 3.11 is continuously changing as
a result of slip between the two systems. This is normal). Polarity of the slip frequency is relative
to the frequency of the line. That is, if the line frequency is 58 Hertz and the bus frequency is 60
Hertz, the slip frequency is -2. As soon as the line frequency rises above 60 Hertz, slip
frequency has no sign and is assumed to be positive.
COMMISSIONING TESTING
Because the commissioning of this relay may be a new installation or a retrofit, special precautions should
be taken to ensure that all tests are performed with safety as the utmost concern. Any CT circuit signals that
are routed through this device as part of a protection scheme including discrete relays or as a stand-alone
device, should be shorted and isolated from this relay during these tests until the final instrument transformer
current circuit check.
