K is a constant which depends of the generators size and design
NS2PTOC has a wide range of K settings and the sensitivity and capability of
detecting and tripping for negative sequence currents down to the continuous
capability of a generator.
In order to match the heating characteristics of the generator a reset time parameter can
be set.
A separate definite time delayed output is available as an alarm feature to warn the
operator of a potentially dangerous situation.
8.9.3 Function block
IEC08000359-2-en.vsd
NS2PTOC
I3P*
BLOCK
BLKST1
BLKST2
TRIP
TR1
TR2
START
ST1
ST2
ALARM
NSCURR
IEC08000359-1-EN V2 EN
Figure 121: NS2PTOC function block
8.9.4 Signals
Table 141: NS2PTOC Input signals
Name
Type Default Description
I3P GROUP
SIGNAL
- Group connection for neg seq.
BLOCK BOOLEAN 0 Block of function
BLKST1 BOOLEAN 0 Block of step 1
BLKST2 BOOLEAN 0 Block of step 2
Table 142: NS2PTOC Output signals
Name
Type Description
TRIP BOOLEAN Common trip signal
TR1 BOOLEAN Trip signal for step 1
TR2 BOOLEAN Trip signal for step 2
START BOOLEAN Common start signal
ST1 BOOLEAN Start signal for step 1
Table continues on next page
Section 8 1MRK 502 048-UEN A
Current protection
244
Technical manual