Basler Electric BE1-851 - Manual (Page 165)

SL-143 = 1
SL-243 = 1
SL-343 = 1
SL-101 = 1
SL-VOA = 0
SL-VO1 = VO11
SL-VO2 = 50TPT
SL-VO3 = 51PT
SL-VO4 = 50TNT
SL-VO5 = 51NT
SL-VO6 = 0
SL-VO7 = 0
SL-VO8 = 0
SL-VO9 = 0
SL-VO10 = 0
SL-VO11 = 50TPT+50TNT+51PT+51NT
SL-VO12 = 50TPPU+50TNPU+51PPU+51NPU
SL-VO13 = 0
SL-VO14 = 0
SL-VO15 = 0
Feeder_1 Logic Scheme
Logic scheme Feeder_1 is meant for use on a feeder breaker and provides overcurrent and breaker
failure protection for a typical feeder in a non-directional overcurrent protection application. This logic
scheme is intended for use in conjunction with other programmable relays using the BUS and BACKUP
logic schemes to provide protection when the relay is out of service. Automatic reclosing and other control
functions such as virtual switches are not provided. When used with other programmable relays using
logic scheme BUS and BACKUP, this scheme can provide complete high-speed overcurrent protection
for the transformers.
The components of Feeder_1 logic are summarized in Tables 8-5 through 8-8. Figure 8-3 is a one-line
diagram of Feeder_1 logic and Figure 8-4 is a diagram representing the logic settings and equations of
Feeder_1 logic.
Normal Operation - Protection
The 51 function blocks and the breaker failure function block re-trip output are enabled in the logic for
tripping via OUT1. The 50T function blocks are enabled in the logic for tripping through OUT2. Each
overcurrent function block can be disabled by setting its pickup setting at 0 in each of the four setting
groups. The 50T ground (N) and negative-sequence (Q), and the 51N and 51Q overcurrent function
blocks are torque controlled by IN3. Modifying the inputs to these function blocks can disable all N & Q
function blocks or only the 51N & Q function blocks.
Normal Operation - Setting Group Selection
Setting group selection can be done automatically or by communications command/HMI override.
Automatic setting group changes for cold load pickup and/or dynamic setting adjustments are enabled by
the SP-GROUP# commands. Setting group changes initiate by a contact sensing input is not
accommodated in this scheme. IN2, IN3, or IN4 can be reprogrammed to provide this function if desired.
The automatic change logic can be disabled by IN2.
Normal Operation - Bus Protection
When any of the 50T or 51 overcurrent function blocks is picked up, OUT4 closes. The signal from OUT4
is wired to IN2 of the upstream relay using BUS logic. The upstream relay blocks the 50T elements that
are set to trip the bus breaker or bus lockout relay. If the fault is not on a feeder, the 50T elements of the
bus relay are not blocked. The bus relay 50T elements are set with a time delay of 2 to 4 cycles to provide
a minimal coordination interval for feeder relay OUT4 to close. Should there be a problem with the
blocking logic, the bus relay 51 functions are not blocked to allow bus fault clearing with a traditional
coordination interval.
9289900990 Rev R BE1-851 Application 8-9