ABB RELION REB500 Technical Manual page 87

1MRK 505 406-UEN B
The logic solves the following problem (see
IEC19000435 V1 EN-US
Figure 31:
The operation of the logic is as follows (POTT solution):
Bay protection functions REB500
Technical manual
A1 B1
A2 B2
B1
A1
A2
B2
B1
A1
B2
A2
Reversal of power direction
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Figure 31)
Relays A1, B1 and B2
t = 0 s :
detect the fault in
the OR zone and
send a signal to the
Remote end. Relay
A2 detects a
backward fault.
t = sign.rec.:
Relays A1, B1 and A2
receive a signal from
the Remote end.
CB A1 opens before
CB B1 opens. Relay A2
t = CB open :
detects the fault in
the OR zone, but still
receives a signal from
the remote end, for
example, it trips and
opens the "Healthy"
line.
18000030-IEC19000435-1-en.vsdx
Section 5
Bay protection functions
81