Protection Engineering Basics and Schemes Protection Engineering | Page 75

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86 for master trip or lock out relay
96 for DC supply supervision
87 for differential relay
21 for Distance Relay
27 for under voltage relay
59 for over voltage relay
81 for frequency relay
Breaker failure relay is inter tripping relay , but it will
show by associated breaker
but nowadays in some drawing you see relay make and
number in place of ansi code, like RET670, 7SJ512 ,P121
etc.
Most of the drawings are showing relays in inactive
forms, but remember when relay shown in drawing is
active it must be mention in drawings.
in drawing, first page is dedicated to front view of panel
where relays, indication LEDs, and control equipment of
relays and panels are shown
pg. 75