ABB Relion 650 Series Technical Manual page 111

1MRK 511 424-UEN B
BlkLevel2nd
second
harmonic
StartCurr_OC1
Voltage
control or
restrai nt
feature
Selected v oltage
Selected restrain current
IEC05000831 V2 EN-US
Figure 40: Simplified internal logic diagram for built-in first overcurrent step that is, OC1 (step OC2 has the
same internal logic)
Bay control REC650 2.2 IEC
Technical manual
Logic in figure 39
1. The selected currents and voltage are given to built-in protection elements.
Each protection element and step makes independent decision about status of
its START and TRIP output signals.
2. More detailed internal logic for every protection element is given in the
following four figures.
3. Common START and TRIP signals from all built-in protection elements &
steps (internal OR logic) are available from multipurpose function as well.
a
a>b
AND
b
Enable
Second harmonic
check
a
a>b
b
OC1=On
BLKOC1
X
DIR_OK
Directionali ty
check
Curren t
Restrai nt
Feature
I > k I
mea sure d restra int
can be summarized as follows:
DEF time
selected
DEF
AND
Inverse
Inverse
time
selected
Section 6
Multipurpose protection
BLKTRO C1
AND
OR
IEC05000831-2-en.vsdx
TROC1
STOC1
105