ABB Relion 670 Series Technical Reference Manual page 855

1MRK505222-UUS C
13.8.8.2
13.8.8.3
13.8.8.4
Technical reference manual
Principle of operation
Negative sequence overcurrent protection (LCNSPTOC, 46) is a definite time stage
comparator function. The negative sequence input current from the SMAI block is
connected as input to the function through a group connection I3P in PCM600. This
current is compared against the preset value and a pickup signal will be set high if the
input negative sequence current is greater than the preset value Pickup2. Trip signal
will be set high after a time delay setting of tI2. BLOCK input will block the complete
function. BLKTR will block the trip output. The negative sequence current is available
as service value output I2.
Function block
LCNSPTOC (46)
I3P* TRIP
BLOCK RI
BLKTR
ANSI09000769-1-en.vsd
ANSI09000769 V1 EN
Figure 423: LCNSPTOC (46) Function block
Input and output signals
Table 475: LCNSPTOC (46) Input signals
Name Type
I3P GROUP
SIGNAL
BLOCK BOOLEAN
BLKTR BOOLEAN
Table 476: LCNSPTOC (46) Output signals
Name Type
TRIP BOOLEAN
RI BOOLEAN
Scheme communication
Default Description
- Three phase group signal for current inputs
0 Block overall function
0 Block trip signal
Description
Trip signal negative sequence over current protection
Start signal for negative sequence over current
protection
Section 13
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