ABB REF630 - Page 9

protection, with three independent stages, is
used for earth-fault protection of the
substation bus and the incoming feeder, and
for back-up protection of the outgoing feeders.
The IED offers distance protection including
both circular (mho) and quadrilateral (quad)
zone characteristics, three independent zones
with separate reach settings for phase-to-
phase and phase-to-earth measuring elements
and two zones for controlling auto-reclosing
of circuit breakers. Further, the IED offers
automatic switch onto fault logic with voltage
and current based detection options.
The IED offers voltage protection functions
including three-phase undervoltage and
overvoltage protection with three
independent stages each, both with phase-to-
phase or phase-to-earth measurement. The
IED offers overfrequency, underfrequency
and rate-of-change of frequency protection to
be used in load shedding and network
restoration applications.
In addition the IED offers three-pole multi-
shot autoreclose functions for overhead line
feeders.
The IED incorporates breaker failure
protection for circuit breaker re-tripping or
back-up tripping for the upstream breaker.
GUID-8D94ABFF-3F94-4C26-BDF5-2F4DD4B906FB V1 EN
Figure 2. Protection function overview of preconfiguration A
Feeder Protection and Control 1MRS756380 A
REF630
Product version: 1.0 Issued: 15.09.2009
ABB 9