Multi-Breaker Applications - ABB REG670 Applications Manual

1MRK 502 071-UEN -
7.4.2.5
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
REFPDIF
I3PW1CT1
IdN/I
I3P
IEC09000112-4 V2 EN
Figure 75: Connection of restricted earth-fault, low impedance function
REFPDIF for a solidly earthed reactor

Multi-breaker applications

Multi-breaker arrangements including ring, one and a half breaker, double breaker
and mesh corner arrangements have two sets of current transformers on the phase
side. The restricted earth-fault protection, low impedance function REFPDIF has
inputs to allow two current inputs from each side of the transformer. The second
winding set is only applicable for autotransformers.
A typical connection for a star-delta transformer is shown in figure 76.
Section 7
Differential protection
Reactor
IEC09000112-4.vsd
179