91
Monitoring of AC analogue
measurements
Chapter 11
Verifying settings by secondary
injection
10
Monitoring of AC analogue measurements
Stabilized ac current and voltage generators and corresponding current, voltage, power
and frequency meters with very high accuracy are necessary for testing the alternating
quantity measuring function. The operating ranges of the generators must correspond
to the rated alternate current and voltage of each terminal.
Prepare the terminal for verification of settings as outlined in section “Preparing for
test” in this chapter. Connect the generators and instruments to the corresponding input
terminals of a unit under test.
Procedure
1.
Supply the terminal with voltages and currents.
Check that the values presented on the HMI unit correspond to the
magnitude of input measured quantities within the limits of de-
clared accuracy. The mean service values are available under the
submenu:
Service Report/ServiceValues
The phasors of up to five input currents and voltages are available
under the submenu:
Service Report/Phasors/Primary
2.
Check the operation of ADBS or IDBS when applicable. Com-
pare with the expected values.
The operation of ADBS or IDBS function can be checked sepa-
rately with the RepInt = 0 setting. The value on the HMI follows
the changes in the input measuring quantity continuously.
3.
Check the set operate levels of the monitoring function by
changing the magnitude of input quantities and observing the
operation of the corresponding output relays.
The output contact changes its state when the changes in the input
measuring quantity are higher than the set values HIWARN, HI-
ALARM, or lower than the set values LOWWARN, LOW-
ALARM.
4.
Continue to test another function or complete the test by set-
ting the test mode to off.
