Double Circuit Breaker Busbar Arrangement - ABB REB670 Applications Manual

Section 6
Differential protection
6.1.4.6
134
Table 16: Typical solutions for H-type stations
Version of REB670 IED
3PH; 2-zones, 4-bays BBP (A20)
3PH; 2-zones, 8-bays BBP (A31)
1Ph; 2-zones, 12-bays BBP (B20)
1Ph; 2-zones, 12-bays BBP (B21)
1Ph; 2-zones, 24-bays BBP (B31)
Please note that table 16
contain any VT inputs.
For station with double zone protection and just one set of CTs in the bus-section bay, it
might be required, depending on the client requirements, to provide the special scheme for
disconnection of bus-section CT when the bus-section CB is open. For more information,
refer to figure 45.

Double circuit breaker busbar arrangement

The circuit breaker, disconnectors and instrument transformers are duplicated for every
feeder, as shown in figure 57.
152
252
152
ANSI06000018 V1 EN
Figure 57: Example of double breaker station
This is an extremely flexible solution. In normal service all breakers are closed. The
requirement for busbar protection scheme is that the scheme must have two independent
differential zones, one for each busbar. If there is an internal fault on one of the two buses
all circuit breakers associated with the faulty busbar have to be tripped, but supply to any
Number of differential
zones/number of feeders
per zone
1/4
2/3
NA
NA
NA
is given for the preconfigured versions of REB670 which do not
252 252
152
1MRK 505 337-UUS -
Number of REB670 IEDs
required for the scheme
1
1
NA
NA
NA
252 252
152 152
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Application manual
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