Date Code 20000421 Applications 5-21
SEL-251, -2, -3 Instruction Manual
The TFT (trip failure time) settings provide the time delay for the A1 output contacts.
With the SEL-251 Relay ALARM output contact supervising the SEL-251C Relay TRIP, the
SEL-251 Relay A4 output contact can function as an extra ALARM output contact by the
placement of jumper JMP3 in the alarm position. The A4 output contact is made a "b" contact
by soldering wire jumper JMP5 in the B position. This output contact can alarm a local
annunciator or SCADA RTU for feeder relay failure.
Figure 5.13: Distribution Feeder Relay Backup Scheme
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