ABB REL670 Installation And Commissioning Manual page 136

10.2.2
128
Secondary system supervision
2. Connect the nominal dc voltage to the DISCPOS binary input.
• The signal BLKU should appear with almost no time delay.
• No signals BLKZ and 3PH should appear on the IED.
• Only the distance protection function operates.
• No other undervoltage-dependent functions must operate.
3. Disconnect the dc voltage from the DISCPOS binary input terminal.
4. Connect the nominal dc voltage to the MCBOP binary input.
• The BLKU and BLKZ signals should appear without any time delay.
• No undervoltage-dependent functions must operate.
5. Disconnect the dc voltage from the MCBOP binary input terminal.
6. Disconnect one of the phase voltages and observe the logical output
signals on the terminal binary outputs.
BLKU and BLKZ signals should simultaneously appear.
7. After more than 5 seconds disconnect the remaining two phase volt-
ages and all three currents.
• There should be no change in the high status of the output signals
BLKU and BLKZ.
• The signal 3PH will appear.
8. Establish normal voltage and current operating conditions simulta-
neously and observe the corresponding output signals.
They should change to logical 0 as follows:
• Signal 3PH after about 25 ms
• Signal BLKU after about 50 ms
• Signal BLKZ after about 200 ms
Measuring the operate value for the negative sequence function
Measure the operate value for the negative sequence function, if included in the IED.
Procedure
1. Simulate normal operating conditions with the three-phase currents
in phase with their corresponding phase voltages and with all of
them equal to their rated values.
2. Slowly decrease the measured voltage in one phase until the BLKU
signal appears.
3. Record the measured voltage and calculate the corresponding neg-
ative-sequence voltage according to the equation.
Observe that the voltages in the equation are phasors:
Chapter 11
Verifying settings by secondary
injection