GE N60 Instruction Manual page 561

CHAPTER 7: COMMANDS AND TARGETS
• What to do: Contact the factory and supply the failure code noted in the display. Text in the message identifies the
failed module (for example, H81). If operated on a Process Card failure, the Module Fail self-test seals-in (latches) till the
UR-series device is restarted.
PROCESS BUS FAILURE
• Description of problem: Mission critical data is not available via the process bus. An AC quantity is considered critical if
both AC bank origins and the crosschecking settings are other than None. This self-test is also initiated by an AC input
discrepancy being detected. See the description in the Crosschecking setting in the HardFiber manual for further
information. In addition, this self-test can be initiated by user logic responding to loss of critical contact input/output
or other data using 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 the
operand 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 the
result of problems in the input signals to the Bricks, or faults in the Brick input conditioning hardware. If the error was
annunciated the first time significant signal was encountered, suspect the former cause and check the copper
connections 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 change
an AC bank Crosschecking setting to None, until the Process Bus Failure clears. Once the problem AC bank has been
identified, the values from each of the two Bricks can be examined individually by temporarily mapping each to an AC
bank with a single origin.
7.2.2.5 HardFiber minor self-test error messages
PROCESS BUS TROUBLE
• Description of problem: Communications problems with one or more Bricks. The text of the message identifies the
affected field units. This self-test is initiated by low received signal levels at either the Brick or Process Card end, and
by 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 be
available to the UR device.
• What to do: Check the field unit actual values. An indication of equipment mismatch means that messages are being
received 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 Card
port, and that the field unit settings are correct. An indication of communications loss means that no messages are
being received. Check that the patching is correct, and that the Brick has power. If that is not the problem, use a
professional optical fiber connector cleaning kit to clean both sides of all optical fiber connections from the Process
Card through to the affected Brick. If the problem continues after cleaning, consult the factory.
BRICK TROUBLE
• Description of problem: Brick internal self-testing has detected 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 device.
• What to do: Check the Brick environment for over/under temperatures and the voltage of its power source. If the
ambient temperature and supply voltage are within Brick specifications, consult the factory. Troubles resulting from a
Brick output failing to respond to an output command can only be detected while the command is active, and so in
this case the target is latched. A latched target can be unlatched by pressing the front panel reset key if the command
has ended, however the output can still be non-functional.
N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
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