ABB REB670 Series Applications Manual page 126

Section 6
Differential protection
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 20: 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
contain any VT inputs.
For station with just one CT in the bus-coupler bay, it might be required, depending on the
client requirements, to provide the special scheme for disconnection of bus-coupler CT when
the bus-coupler CB is open. For more info please refer to Figure 47.
Some principle overall drawings of how to use REB670 in this type of station are given in
Figure 62
120
20 is given for the preconfigured versions of REB670 which do not
to Figure 66.
Number of feeders in the
station (excluding bus-
coupler bay)
)
3*
)
7*
NA
)
11*
)
23*
1MRK 505 370-UEN D
Number of REB670 IED required
for the scheme
1
1
NA
3
3
Busbar protection REB670
Application manual