Micom P631 - Limit Value Monitoring (Function Groups LIM_1 and LIM_2); Monitoring Minimum and Maximum Phase Currents

3.29 Limit Value Monitoring (Function Groups LIM_1 and LIM_2)
Each of the limit value monitoring functions, LIM_1 and LIM_2, is designed for the
monitoring of the minimum and maximum phase currents for a user-selected
transformer end.
The limit value monitoring functions LIM_1 and LIM_2 can be enabled or disabled
using setting parameters.
3.29.1 Monitoring Minimum and Maximum Phase Currents
Two limit value monitoring functions (LIM_1 and LIM_2) are implemented and can
be assigned to both transformer ends.
For each limit value monitoring function, a setting parameter is provided for this
assignment by the user. The function will then monitor the minimum and
maximum phase currents for the selection. If a maximum phase current exceeds
the relevant set threshold or if a minimum phase current falls below the relevant
set threshold, a signal is issued once a set time has elapsed.
Function group LIM_1 will serve as an example to illustrate the operation of the
limit value monitoring functions in the following figures.
62Z5080A
LIM_1:
Select. meas. input
[ 019 111 ]
0
1
0: End a
1: End b
10
IA,a
IB,a
IC,a
IN,a
IA,b
IB,b
IC,b
IN,b
IA,y
IB,y
IC,y
IN,y
Fig. 3-138: Selection of measured values
P631
3 Operation
3-170 P631/EN M/R-11-C // P631-310-650