Reszta to independent, definite-time delay overcurrent relay.

cccccccccccccccccccccccccc
INDEPENDENT (DEFINITE) TIME
OVERCURRENT RELAYS

Each protection unit comprises a definite-time delay overcurrent relay in which the operation of the current sensitive element simply initiates the time delay


Overcurrent relays are normally also provided with
elements having independent or definite time
characteristics. These characteristics provide a ready
means of co-ordinating several relays in series in
situations in which the system fault current varies very
widely due to changes in source impedance, as there is
no change in time with the variation of fault current
http://www.fecime.org/referencias/npag/chap9-122-151.pdf
ccccccccccccccccccccccccccccccccccccccccccccccccccccccc

This model (Figure 1) represents the operation of >definite time overcurrent relay</b after a fault occurred at the transmission line.
http://www.simulink-simpowersystems-examples.com/2015/03/Def...
ccccccccccccccccccccccc

This would have a time/current characteristic as in Figure Lib The addition of a timing device results in a definite time-delay overcurrent relay.
https://books.google.com/books?id=HMLBEXay1DUC&pg=PA127&lpg=...

--------------------------------------------------
Note added at 17 mins (2016-10-04 14:51:14 GMT)
--------------------------------------------------

cccccccccccccccccc

Definite Time Overcurrent Relays
In this type, two conditions must be satisfied for operation (tripping), current must exceed the setting value and the fault must be continuous at least a time equal to time setting of the relay.



vs. Instantaneous Overcurrent relay (Define Current)
Definite current relay operate instantaneously when the current reaches a predetermined value.

http://electrical-engineering-portal.com/types-and-applicati...