ABB REB670 Applications Manual page 145

1MRK 505 337-UUS -
Application manual
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152
ANSI11000239 V1 EN
Figure 61: Example of double busbar station
This type of busbar arrangement is very common. It is often preferred for larger
installations. It provides good balance between maintenance work requirements and
security of supply. If needed, two busbars can be split during normal service. The
requirement for busbar protection scheme is that the scheme must have two independent
differential zones, one for each busbar. In case of an internal fault on one of the two buses,
bus-coupler circuit breaker and all feeder circuit breakers associated with the faulty bus
have to be tripped, leaving other busbar still in normal operation. Provision for zone
selection, disconnector replica and zone interconnection have to be included into the
scheme design.
This type of busbar arrangement can be protected as described in the following table:
Table 19: Typical solutions for double busbar 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)
*) with just one CT input from bus-coupler bay
Please note that table 19
contain any VT inputs.
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Number of feeders in the
station (excluding bus-
coupler bay)
)
3*
)
7*
NA
)
11*
)
23*
is given for the preconfigured versions of REB670 which do not
Section 6
Differential protection
ZA
ZB
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ANSI11000239-1-en.vsd
Number of REB670 IED
required for the scheme
1
1
NA
3
3
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