Schweitzer Engineering Laboratories SEL-387-0, Instruction Manual

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5.26
SEL-387-0, -5, -6 Relay Instruction Manual
Date Code 20050919
Metering and Monitoring
Through-Fault Event Monitor
Magnitude Limits on
Through-Fault Event
Data
In the above TFE command responses, there are limits, besides the
aforementioned 1200 event limit on stored through-fault events, to data
accumulation. These limits are:
➤
“Number of Through Faults” counts: 65,535 counts
➤
“Total I-squared-t” (per phase): 4,294,967.295 kA
2
seconds
➤
“Duration” for through-fault event: 8191 cycles, converted to
seconds
➤
“IA, IB, IC” for through-fault event 65,535 A, primary
If any of these values exceed their limits, a plus sign (+) is appended to the
above maximum limit number in the display. If “Duration” or “IA, IB, IC”
values are at their maximums or beyond, then the monitor uses the above
maximum values in performing subsequent simple I
2
t calculations and
cumulatively storing calculation results for each monitored phase.
All these through-fault event data are stored in nonvolatile memory.