GE N60 Instruction Manual

Also see for N60: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

7-12 N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUALTARGETS MENU CHAPTER 7: COMMANDS AND TARGETS7Process bus failure major self-test• Description of problem: Mission critical data is not available via the process bus. An AC quantity is considered critical ifboth AC bank origins and the crosschecking settings are other than none. This self-test is also initiated by an AC inputdiscrepancy being detected. See the description of the crosschecking setting in this manual for further information. Inaddition, this self-test can be initiated by user logic responding to loss of critical contact input/output or other datausing the Process Bus Failure Operand user-programmable self-test setting. This setting is located in the Settings >Product Setup > User-Programmable Self Test menu.• Severity: Protection is not available and all contact outputs and shared outputs are de-asserted.• What to do: First rectify any Process Bus Trouble and Brick Trouble self-test errors. Check the actual value of theoperand referenced by the Process Bus Failure Operand setting, and if “On,” determine the cause and rectify.If the problem persists with the foregoing all clear, the cause must be an AC input discrepancy, which is typically theresult of problems in the input signals to the Bricks, or faults in the Brick input conditioning hardware. If the error wasannunciated the first time significant signal was encountered, suspect the former cause and check the copperconnections external to the Brick. Where multiple UR-series devices have self-test errors, look for common causes.To further isolate AC input discrepancy errors, put the relay in test-isolated mode, then one by one, temporally changean AC bank crosschecking setting to none, until the Process Bus Failure clears. Once the problem AC bank has beenidentified, the values from each of the two Bricks can be examined individually by temporarily mapping each to an ACbank with a single origin.Process bus trouble minor self-test• Description of problem: Communications problems with one or more Bricks. The text of the message identifies theaffected field units. This self-test is initiated by low received signal levels at either the Brick or Process Card end, andby the sustained failure to receive poll responses from the proper Brick.• Severity: This self-test error does not directly inhibit protection. However, the affected Brick inputs/outputs may not beavailable to the UR-series device.• What to do: Check the field unit actual values. An indication of equipment mismatch means that messages are beingreceived from a Brick, but there is a discrepancy between the settings and the actual Brick serial number, order code,and/or core number. Check that the correct core on the correct Brick is patched through to the correct Process Cardport, and that the field unit settings are correct. An indication of communications loss means that no messages arebeing received. Check that the patching is correct, and that the Brick has power. If that is not the problem, use aprofessional optical fiber connector cleaning kit to clean both sides of all optical fiber connections from the ProcessCard through to the affected Brick. If the problem continues after cleaning, consult the factory.Brick trouble minor self-test• Description of problem: Brick internal self-testing has detected a trouble internal to the Brick.• Severity: This self-test error does not directly inhibit protection. However, some or all of the affected Brick inputs/outputs may not be available to the UR-series device.• What to do: Check the Brick environment for over/under temperatures and the voltage of its power source. If theambient temperature and supply voltage are within Brick specifications, consult the factory. Troubles resulting from aBrick output failing to respond to an output command can only be detected while the command is active, and so inthis case the target is latched. A latched target can be unlatched by pressing the faceplate reset key if the commandhas ended, however the output can still be non-functional.