ABB REB670 - Page 124

PSCLOSED signal must become active a certain time (>150 ms) before current starts
flowing for example, through arcing. Otherwise this current will not be taken into
account in the busbar protection and this can result in a maloperation. Therefore, good
timing of two auxiliary contacts is definitely required.
The time during which the POSOPEN and POSCLOSED signals disagree (that is, both
binary inputs are active or both are inactive) is monitored by the isolator supervision
function for both of the above two schemes. The maximum time allowed before an
alarm is given can be set according to the disconnector timing.
Table 13 and the following two figures summarize the properties of these two schemes.
Table 13: Treatment of primary object auxiliary contact status within BBP in REB670
Primary equipment Status in busbar protection Alarm facility
Normally
Open
auxiliary
contact status
(“closed” or
“a” contact)
Normally
Closed
auxiliary
contact status
(“open” or “b”
contact)
when
“Scheme 1
RADSS”
is selected
when
“Scheme 2
INX”
is selected
Alarm after
settable time
delay
Information visible on
local HMI
open open closed Last
position
saved
yes intermediate_00
open closed open open no open
closed open closed closed no closed
closed closed closed closed yes badState_11
BBP
input „closed“
input „open“
N.O.
N.C.
1
0
1
0
1
0
closed
open
arcing possible
current
assignment
1) 1)
1) disconnector supervision running
en06000084.vsd
IEC06000084 V1 EN-US
Figure 43: Scheme1_RADSS
Section 6 1MRK 505 370-UUS A
Differential protection
118 Busbar protection REB670 2.2 ANSI
Application manual