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489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
CHAPTER 4: INTERFACES
4.1.6
Diagnostic Messages
Diagnostic messages are automatically displayed for any active conditions in the relay
such as trips, alarms, or asserted logic inputs. These messages provide a summary of the
present state of the relay. The Message LED flashes when there are diagnostic messages
available; press the
MENU
key until the relay displays
TARGET MESSAGES
, then press the
MESSAGE
X
key, followed by the
MESSAGE
T
key, to scroll through the messages. For
additional information and a complete list of diagnostic messages, refer to
4.1.7
Self-Test Warnings
The 489 relay performs self test diagnostics at initialization (after power up), and
continuously as a background task to ensure every testable unit of the hardware and
software is functioning correctly. There are two types of self-test warnings indicating either
a minor or major problem. Minor problems indicate a problem with the relay that does not
compromise protection. Major problems indicate a very serious relay problem which
comprises all aspects of relay operation.
Upon detection of either a minor or a major problem the relay will:
• De-energize the self-test warning relay
• Light the self-test warning LED
• Flash a diagnostic message periodically on the display screen
The 489 self-test warnings are shown below.
Table 4–1: Self-Test Warnings
Message
Severity
Description
Self-Test Warning 1
Replace Immediately
Major
This warning is caused by detection of a
corrupted location in the program memory as
determined by a CRC error checking code. Any
function of the relay is susceptible to
malfunction from this failure.
Self-Test Warning 2
Replace Immediately
Major
This warning is caused by a failure of the
analog to digital converter. The integrity of
system input measurements is affected by this
failure.
Self-Test Warning 3
Replace Immediately
Major
This warning is caused by a failure of the
analog to digital converter. The integrity of
system input measurements is affected by this
failure.
Self-Test Warning 5
Replace Immediately
Major
This warning is caused by out of range reading
of self test RTD 13. The integrity of system
input measurements is affected by this failure.
Self-Test Warning 6
Replace Immediately
Major
This warning is caused by out of range reading
of self test RTD 14. The integrity of system
input measurements is affected by this failure.
Self-Test Warning 7
Replace Immediately
Major
This warning is caused by out of range reading
of self test RTD15. The integrity of system input
measurements is affected by this failure.