Protection Engineering Basics and Schemes Protection Engineering | Page 69

auxiliary 52A make contact ,due to that the Trip coil
energizes and breaker operates.
2.3.3 Shunt reinforcement with sealing:
In this circuit, When Protection Relay operates, PR make
contact and associated parallel make contact energizes,
current flows towards flag indication, when flag
indication on, the upper make contact and lower most
make contact energizes and current through this circuit
move toward breaker auxiliary make contact 52a and
energizes it also, from this closed circuit trip coil (TC)
energizes and breaker operates.
2.4 Trip circuit Supervision:
We need to check that either are circuit are alive at which
our protection scheme located; Please keep in mind all
contacts have voltage difference (in case of open/make
contact) and continuity path (in case of closed/break
contact).
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