4-40
Protection and Control
BE1-951
Figure 4-22. 79SCB Logic
Recloser Reset (79RST). The 79RST provides reset indication and is true when the recloser is in the reset
position.
Recloser Sequence Controled Block (79SCB). This
output becomes TRUE when either the 52 status input
OR the 79C input is TRUE AND the sequence
operation (shot counter) matches one of the
programmed steps of the S<g>-79SCB command.
Figure 4-22 illustrates 79SCB logic. See Figures 4-17
and 4-18 for more details.
Recloser BESTlogic Settings
Reclosing is added to a protection scheme by enabling
the Recloser element and connecting the inputs to the appropriate logic to provide control. this is done using
the SL-79 command. The recloser logic settings are summarized in Table 4-31. Additionally, one or more
of the protection elements must be connected to external elements that are controlled by the SL-<func> or
SL-VO command.
Table 4-31. Recloser Logic Settings
Function
Range/Purpose
Default
Mode
0 = Recloser disabled
1 = Standard power-up operation. After power-up, the STATUS logic must
be TRUE for the Reset time delay or the recloser automatically goes
to Lockout. If the STATUS logic stays TRUE for reset time delay, the
recloser goes to Reset.
2 = Power-up to close. If the recloser was in the Reset state when power
was lost, and when power is restored the STATUS logic is FALSE
(breaker open) and the RI logic is TRUE, the recloser will initiate the
first reclose operation. If the STATUS logic stays TRUE for the reset
time delay, the recloser goes to Reset.
0
RI
OR logic term to initiate the operation of the reclosing function
0
STATUS
OR logic term to indicate breaker status.
TRUE/1 = closed, FALSE/0 = open
0
WAIT
OR logic term to momentarily disable but not reset the recloser
0
LOCKOUT
OR logic term to disable the recloser (drive to Lockout)
0
SL-79 Command
Purpose:
Read or set 79 function block logic.
Syntax:
SL-79[=<Mode>,<RI>,<STATUS>,<WAIT>,<LOCKOUT>]
SL-79 Command Example
1.
Read the recloser logic settings.
>SL-79
1,VO1,/IN2,0,IN3
The reported settings are explained in the following paragraphs.
1
Recloser is enabled for standard, power-up operation.
VO1
Recloser is initiated when output VO1 is TRUE.
/IN2
Breaker status is monitored at contact input 2. (Breaker is closed when IN2 is de-energized.)
0
Reclose Wait is disabled.
IN3
Energizing contact input 3 will block reclosing and drive the recloser to Lockout.
