ABB Relion 670 Series Technical Reference Manual page 859

1MRK505222-UUS C
13.8.10.2
13.8.10.3
13.8.10.4
Technical reference manual
Features:
• Phase wise pickup and trip signals
• Overcurrent protection
• Phase wise RMS current is available as service values
• Single definite time stage trip function.
Principle of operation
Three phase overcurrent (LCP3PTOC, 51) is used for detecting over current
conditions. LCP3PTOC (51) pickups when the current exceeds the set limit PU 51. It
operates with definite time (DT) characteristics, that is, the function operates after a
predefined time tOC and resets when the fault current disappears. The function
contains a blocking functionality. It is possible to block the function output, timer or
the function itself, if desired.
Function block
LCP3PTOC (51)
I3P* TRIP
BLOCK TR_A
BLKTR TR_B
TR_C
RI
PU_A
PU_B
BFI_C
ANSI09000771-1-en.vsd
ANSI09000771 V1 EN
Figure 425: LCP3PTOC (51) Function block
Input and output signals
Table 483: LCP3PTOC (51) Input signals
Name Type
I3P GROUP
SIGNAL
BLOCK BOOLEAN
BLKTR BOOLEAN
Scheme communication
Default Description
- Three phase group signal for current inputs
0 Block all binary outputs by resetting timers
0 Block trip of the function
Section 13
853