Schweitzer Engineering Laboratories SEL-787, Instruction Manual, Page: 205 / 564

5.17
Date Code 20081022 Instruction Manual SEL-787 Relay
Metering and Monitoring
Through-Fault Event Monitoring
IA, IB, and IC show the maximum primary current for each phase, with a
maximum of 100,000 A primary.
A, B, and C show the amount (percent increase) of the present fault for each
phase. Alarm shows those phase(s) that were in the alarm state at the end of
the through-fault event.
Table 5.11 shows events report messages and the reason why these messages
may appear in the events report.
Use the TFE A command to list all the stored through-fault events (not only
the last 20 events) since the monitor was last reset. To list a particular number
of through-fault events, enter the
TFE n command ( n = 1 to 500).
To clear event accumulated data, and all event records, use either the TFE C
(clear) or TFE R (reset) command. Both commands have the same result, so
you can use either of them. Note that when you change the ETHRFLT setting,
the relay also clears the data and records, i.e. it has the same effect as the
TFE C or TFE R command.
Use the TFE P command to preload or change the values of the through fault
event accumulated data, as shown in Figure 5.20 . Enter these values in percent
for each phase, up to a maximum value of 100.0 percent.
=>>TFE P
Winding 1 Total Accumulated Percentage of Through Fault Capability:
A_Phase = 0.00? 60.20
B_Phase = 0.00? 56.0
C_Phase = 0.00? 52
Are you sure (Y,N)? Y
Command Completed
=>>
Figure 5.20 Preload the Values of the Accumulated Data
Table 5.11 Through-Faults Events Report Messages
Message Cause
Invalid Data The accumulated data is corrupt.
Through Fault Event Monitor Disabled The ETHRFLT setting is NA, or evaluates to
logical 0.
Too many events - Data Lost The memory is full.
Through Fault Event Buffer Empty There are no event records in the nonvolatile
memory
Memory resources are low; check for
activity on other ports There is insufficient memory to display the
event records