Protection Engineering Basics and Schemes Protection Engineering | Page 110

5.1 Operation: in normal condition, the fluxes generated
from upper electromagnetic and lower electromagnetic is
not enough for disc rotation.
When abnormal or fault condition occurs in any electrical
quantity let say current, the flux from current coil
increases and causes motion in disc. This motion depends
upon the abnormal current flow.
Nowadays we are using Digital Overcurrent Relays; logic
diagram
of Digital
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