GE 745 TRANSFORMER MANAGEMENT RELAY

GE Power Management 745 Transformer Management Relay 6-21
6 ACTUAL VALUES 6.7 SELF-TEST ERRORS
6
6.7 SELF-TEST ERRORS 6.7.1 DESCRIPTION
The 745 performs self-diagnostics at initialization (after power-up), and continuously thereafter (in a back-
ground task). The tests ensure that every testable unit of the hardware is functioning correctly.
ANY SELF-TEST ERROR INDICATES A SERIOUS PROBLEM REQUIRING SERVICE.
6.7.2 MAJOR SELF-TEST ERRORS
Upon detection of a major self-test error, the 745:
• disables all protection functionality
• turns on the front panel SELF-TEST ERROR indicator
• turns off the front panel IN SERVICE indicator
• de-energizes all output relays, including the SELF-TEST relay
• indicates the failure by inserting an appropriate message in the target message queue
• records the failure in the EVENT RECORDER
6.7.3 MINOR SELF-TEST ERRORS
Upon detection of a minor self-test error, the 745:
• turns on the front panel SELF-TEST ERROR indicator
• de-energizes the SELF-TEST relay
• indicates the failure by inserting an appropriate message in the target message queue
• records the failure in the EVENT RECORDER
All conditions listed in Table 6–3: SELF-TEST ERROR INTERPRETATION cause a target message to be gen-
erated.
CAUTION