7SA511 Line Protection Relay | Commissioning the Relay |
7.3 Guidelines for Commissioning the Relay
Test accuracy is dependent directly on the est environment and the equipment used. Some cautions and recommended procedures a sociated with commissioning tests are listed below.
Do not exceed the limit values given in the specifications in Reference D of this manual.
It is recommended that he actual settings for the relay be used for commissioning tests.
Always press the TargetResetkey to reset the relay after tests that cause LED indications.
Check for the following DURING testing:
Be sure that the correct command (trip) contacts close.
Read the LCD and verify the proper information appears when testing output relays
and remote signaling.
If the relay is connected to a substation control system, ensure correct communication through the rear serial port.
7.3.1Current, Voltage, and Phase Sequence Checks
For the purpose of these tests, the relay should be connected to a normal, correctly operating, 3- phase power system with a load at least 10% of the rated value (address 1105). Under these conditions, there should be no fault indications from the internal monitors, and the measured values displayed in the LCD at address block 5700 should indicate phase currents , neutral currents, and voltages that closely match the expected values. If these values are not as expected or some type of problem is indicated, the following checks should be made.
Incorrect Measured Values
A substantial deviation from expected measured values, or a significant ground current indication can result from incorrectly wired measurement transformers. Check these connections and make corrections if necessary.
Symmetry Error
If a symmetry error, Failure Isymm or Failure Usymm, is indicated in the event log (address block 5100), the transformers and their connections should be checked for interruptions or short circuits. If there are no problems in these areas, then it is likely that the currents or voltages are asymmetrical. If this is a normal operating condition for the system, the symmetry parameters (addresses 2901 - 2904) should be adjusted appropriately. Reference E, “Setting Calculations,” provides information on how to correctly set these parameters.
Summation Error
If a summation error Failure
July 27, 1995 |
