Basic Applications; General; Meshed Corner Application And T-Connection Application; Busbar Protection Applications - ABB REB670 Applications Manual

1MRK 505 337-UUS -
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Application manual

Basic applications

General

Basic types of applications for REB670 IED are shown and described in this chapter. For
these applications usually three phase version of the IED, with two differential zone and
four (or even eight) 3-phase CT inputs, is used.

Meshed corner application and T-connection application

The REB670 general differential function is suitable for application on mesh-corner
arrangements. Mesh corners might have four or even up to six CT inputs and are basically
simple single busbar arrangements. A similar application will occur when a T-protection
is required for breaker-and-a-half or ring busbar arrangements.
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ANSI11000237-1-en.vsd
ANSI11000237 V1 EN
Figure 39: Example of REB670 application on T-connection

Busbar protection applications

General
A busbar protection is a device which protects busbars against short-circuits and ground-
faults. In the early development of electricity systems, no separate protection device was
used for busbar protection. Remote end line protections were used as main protection for
busbar faults. With the increased short-circuit power in the network separate differential
IEDs for busbar protection have to be installed in order to limit the damage caused by the
primary fault currents. In the same time, it is also a must to secure the network stability,
Section 6
Differential protection
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