protection functions. This principle is used in cases where the primary process
requires absolute dependability and security from the supplying feeder protection.
3.3
LED indication control
3.3.1
Function block
Figure 21: Function block
3.3.2
Functionality
The protection relay includes a global conditioning function LEDPTRC that is used
with the protection indication LEDs.
LED indication control should never be used for tripping purposes.
There is a separate trip logic function TRPPTRC available in the relay
configuration.
LED indication control is preconfigured in a such way that all the protection
function general start and operate signals are combined with this function
(available as output signals
OUT_START
and
OUT_OPERATE
). These signals are
always internally connected to Start and Trip LEDs. LEDPTRC collects and combines
phase information from different protection functions (available as output signals
OUT_ST_A /_B /_C
and
OUT_OPR_A /_B /_C
). There is also combined earth fault
information collected from all the earth-fault functions available in the relay
configuration (available as output signals
OUT_ST_NEUT
and
OUT_OPR_NEUT
).
3.4
Programmable LEDs
1MRS757644 H
Basic functions
620 series
Technical Manual
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