Feeder_4 logic scheme, Normal operation - control, Normal operation - protection – Basler Electric BE1-851 User Manual

Page 191: Normal operation - reclosing, Feeder_4 logic scheme -35, Normal operation - control -35, Normal operation - protection -35, Normal operation - reclosing -35

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SL-143 = 2

SL-243 = 2

SL-343 = 2

SL-101 = 1

SL-VOA = ALMMAJ

SL-VO1 = VO11+BFPU+101T

SL-VO2 = 79C+101C

SL-VO3 = IN4*/343

SL-VO4 = VO12*/VO5*IN4*/343

SL-VO5 = BFT

SL-VO6 = 0

SL-VO7 = 0

SL-VO8 = 0

SL-VO9 = /IN2+143+/101SC+VO5+150TPT+150TNT

SL-VO10 = VO11

SL-VO11 = 50TPT+50TNT+150TPT+150TNT+51PT+51NT

SL-VO12 = 50TPPU+50TNPU+150TPPU+150TNPU+51PPU+51NPU

SL-VO13 = 0

SL-VO14 = 0

SL-VO15 = /IN4+343

Feeder_4 Logic Scheme

Logic scheme Feeder_4 is meant for use on a feeder breaker and provides all overcurrent and breaker

failure protection, reclosing, and control functions required for a typical feeder in a non-directional

overcurrent protection application. This logic is intended for use in conjunction with redundant protective

relays such as existing electromechanical relays to provide backup when the relay is out of service.
Automatic reclosing is initiated by the breaker opening. Reclosing is disabled after a manual trip by a

control switch slip contact. In this logic scheme, the disable logic is connected to the reclose initiate (RI)

input. Once re-enabled, the recloser will start the sequence and automatically close the breaker if it is

open.
When used in conjunction with other programmable relays using logic scheme BUS, it can provide

complete overcurrent protection for the transformers, bus, and feeders in a radial system substation.
The components of Feeder_4 logic are summarized in Tables 8-17 through 8-20. Figure 8-9 is a one-line

diagram of Feeder_4 logic and Figure 8-10 is a diagram representing the logic settings and equations of

Feeder_4 logic.

Normal Operation - Control

The virtual breaker control switch is programmed to provide manual trip and close control of the breaker.

The control functions of this logic scheme use both traditional contact sensing inputs and virtual switches.

Virtual switches that are not needed may simply go unused. The protection engineer may choose to free

up contact sensing inputs for other uses by using the virtual switches exclusively for the various control

functions.

Normal Operation - Protection

The 50T and 51 function blocks and the breaker failure function block re-trip output are enabled in

Feeder_4 logic for tripping via OUT1. Setting the pickup at zero in the four setting groups can individually

disable each overcurrent function block.
The 50TN, 50TQ, 51N, and 51Q function blocks are torque controlled by Virtual Switch 243. All N and Q

function blocks or only the 51N and 51Q function blocks may be inhibited. This is done in BESTlogic by

modifying the inputs to the function blocks.

Normal Operation - Reclosing

The reclosing logic in Feeder_4 is initiated by the breaker opening. Automatic reclosing is disabled for a

manual trip by a control switch slip contact. Setting the first reclose time = zero can disable the recloser

function block in the four setting groups.

9289900990 Rev R

BE1-851 Application

8-35

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