Basler BE1-CDS220, Instruction Manual

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8-22 Application BE1-CDS220
SL-643=0
SL-743=2
SL-101=1
SL-VOA=0
SL-VO1=151PT+51NT+151NT+151QT+87RT+87UT
SL-VO2=250TQT
SL-VO3=BFT+62
SL-VO4=251PT+251NT+251QT+87RT+87UT+VO9+101T+BFPU
SL-VO5=/IN3*/IN4*101C
SL-VO6=/IN5
SL-VO7=0
SL-VO8=0
SL-VO9=87RT*/VO15*IN2+87UT*/VO15*IN2+/VO15*IN2*IN6
SL-VO10=VO11+IN7*IN7*IN7*150TQPU
SL-VO11=
151PT+251PT+51NT+151NT+251NT+151QT+251QT+87RT+87UT
SL-VO12=
87UT+51NPU+
87RPU
SL-VO13=43
SL-VO14=0
SL-VO15=/IN8+743
Protection Elements
Referring to Figure 8-8, the 87 and 151 protection elements are connected to the high-side CT, input 1
and the 87 and 251 protection elements are connected to the low-side CT, input 2. The 51 protection
element (N only) is connected to a ground CT at the grounded side of a delta-wye transformer. The
ground-input (G) is an option on the BE1-CDS220 and must be ordered. Paralleled CTs inside a delta
tertiary (3Io) can also feed the 51N. The 87, 51, 151, and 251 protection elements are logic enabled to
provide a trip by the settings shown in Table 8-16. Protection elements set at 0 are setting disabled and
will not provide a trip output even if logic enabled.
Typically, the TX-W-BU scheme would be applied with a BE1-851 on the feeder circuits, and a BE1-851 or
BE1-CDS220 on the bus main breaker interlocked with the feeder relay to provide high-speed, bus fault
protection. This combination provides independent, overlapping backup protection in the event of a
common mode failure.
Typically, the 87 protection element provides high speed restrained differential and unrestrained
differential phase and ground protection for faults inside the differential zone. At the same time, it provides
security against misoperations resulting from transformer inrush by restraining and preventing a trip in the
presence of 2
nd
and 5
th
harmonics.
Typically, the 151 protection element is coordinated with the low-side bus protection to provide Phase,
Neutral, and Negative-Sequence timed backup protection for the low-side bus if the bus protection is out
of service.
Typically, the 251 protection element is coordinated with the low-side feeder protection to provide Phase,
Neutral, and Negative-Sequence timed backup protection for feeder faults if the feeder protection is out of
service.
Typically, the 51N protection element is coordinated with the low-side bus and feeder protection to provide
Neutral (ground) timed backup protection for transformer low-side, bus, and feeder ground faults if any
primary zone of protection is of service.
Typically, the 250T protection element is set to coordinate with a high-speed bus-interlocking scheme (851
or BE1-CDS220) to provide a definite time coordination interval of 18 to 20 cycles for bus fault backup
protection. The 250T protection element should have a pickup setting greater than the highest feeder
instantaneous element to ensure that it will not pickup before any feeder relay.
Typically, the 50T protection element is set to provide fault detection but not to be picked-up on load. This
element provides current supervision for the external BFI input associated with the BF protection element.