Micom P631, Technical Manual

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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
1 0
I̲A,a
I̲B,a
I̲C,a
I̲N,a
I̲A,b
I̲B,b
I̲C,b
I̲N,b
I̲A,y
I̲B,y
I̲C,y
I̲N,y
Fig. 3-138: Selection of measured values
P631 3 Operation
3-170 P631/EN M/R-11-C // P631-310-650