TB XRI1-IR 02.00 E
3
1
Introduction and application
The digital relay type
XRI1-IR
as time overcurrent pro-
tection is designed for the use in electrical machines,
lines and grids.
The protective functions of
XRI1-IR
which are imple-
mented in only one device are summarized as follows:
•
Independent (Definite) time overcurrent relay.
•
Inverse time overcurrent relay with selectable charac-
teristics.
•
Integrated determination of fault direction for appli-
cation to doubly infeeded lines or meshed systems.
Furthermore, the relay
XRI1-IR
can be employed as a
back-up protection for distance and differential protec-
tive relays.
2
Features and characteristics
•
Digital filtering of the measured values by using dis-
crete Fourier analysis to suppress the high frequence
harmonics and DC components induced by faults or
system operations
•
Selectable protective functions between:
definite time overcurrent relay and
inverse time overcurrent relay
•
Selectable inverse time characteristics according to
BS 142 and IEC 255-4:
Normal Inverse (type A)
Very Inverse (type B)
Extremely Inverse (type C)
•
Reset setting for inverse time characteristics select-
able
•
High set overcurrent unit with instantaneous or de-
finite time function.
•
Two-element (low and high set) overcurrent relay
both for phase and earth faults.
•
Directional feature for application to the doubly in-
feeded lines or meshed systems.
•
Numerical display of setting values, actual mea-
sured values and their active, reactive components,
memorized fault data, etc.
•
Blocking e.g. of high set element (e.g. for selective
fault detection through minor overcurrent protection
units after unsuccessful AR).
•
Relay characteristic angle for phase current direc-
tional feature selectable
•
Switch failure protection
•
Storage of tripping values and shut-down times
of eight failure events
•
Free assignment of output relays
•
Serial data exchange via RS485 interface possible
with SEG RS485-Pro Open Data Protocol
•
Suppression of indication after an activation
(LED flash)
