Breaker Health Monitoring - GE SMOR-B GEK 105593C Instructions Manual

GEK-105593C
CLOSE CIRCUIT SUPERVISION

2.2.5. BREAKER HEALTH MONITORING

To supervise the breaker health, SMOR system calculates and stores, for each operation, the accumulated
values for the square of the current multiplied by the opening time of the breaker (ΣI 2 t) on each of the three
phases. If the nominal current is not exceeded, as is the case for a manual opening command with no fault
current, the relay uses the nominal current value instead of the measured value.
The value I 2 t is accumulated and stored independently for each phase. These values can be accessed
either by local MMI or by GE-LOCAL communication software.
The function has an "Integration Time Selector" setting which can be used to assign a fixed opening time
(given by another "Integration Time" setting). Otherwise it allows the unit to measure this time from the
moment the opening command is given until the moment when the breaker opens.
The "Accumulative Current Limit" setting establishes a threshold for the breaker's interruption capability (it is
advisable to set this to the limit supplied by the manufacturer). When this threshold is passed on any of the
three phases, the system gives an alarm. In addition, the system incorporates a counter for the number of
opening operations carried out.
The purpose of this function is to allow maintenance to be carried out in a more accurate method than using
fixed time periods. Once this maintenance operation has been carried out, the values for both the I 2 t and
number of opening operations, can be reset to zero.
In order to be able to take into account the history of the breaker, in the case where the breakers were
already in use before the installation of the relay, the system allows to set an initial value for the ΣI 2 t and the
number of opening operations carried out. Similarly, these values can be adjusted to a given value in order
to take into account the operations carried out during the protection testing.
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