ABB REB670 Series Applications Manual page 132

Section 6
Differential protection
QA1
BI1
QA2
BI2
BI3
QA3
IEC06000123 V1 EN-US
Figure 68: Combination between one-and-half and double breaker station layouts
This type of stations can be encountered very often in practice. Usually the station is arranged
in such a way that double breaker bays can be, at a later stage, transformed into one-and-half
breaker setup. For busbar protection this type of station can be protected in exactly the same
way as one-and-half breaker stations described above. The same type of IEDs can be used, and
same limitations regarding the number of diameters apply.
QA1 QA2
BI1
IEC06000124 V1 EN-US
Figure 69: Combination between double breaker and double busbar station layouts
In this type of arrangement the double breaker bay has in the same time the role of the bus-
coupler bay for normal double busbar single breaker stations. Therefore, zone interconnection,
zone selection and disconnector replica facilities have to be provided for all double busbar
bays. Because of the very specific requirements on zone interconnection feature, the following
should be considered for this type of application:
• current inputs CT1 and CT2 shall be used for the first double breaker bay.
• current inputs CT3 and CT4 shall be used for the second double breaker bay.
• current inputs CT5 and CT6 shall be used for the third double breaker bay (only available in
1ph version).
Accordingly the following solutions are possible:
126
QA1 QA1 QA1
BI1 BI1 BI1
QA2 QA2 QA2
BI2
BI2 BI2
BI3 BI3 BI3
QA3 QA3 QA3
QB1 QB2
QA1 QA2
BI2
BI1 BI2
QA1
BI1
QA1
BI1
QA2
BI2
BI3
QA3
QA1 QA2
BI1 BI2
ZA
ZB
QB1 QB2
QA1
BI1
xx06000124.vsd
1MRK 505 370-UEN D
ZA
ZB
xx06000123.vsd
Busbar protection REB670
Application manual