SEG Electronics GmbH
Manual MRG3
34
DOK-TD-MRG3, Rev. D
4.8 Fault recorder
The MRG3 has a fault value recorder which records the measured analog values as instantaneous
values.
The instantaneous values
U
L1
; U
L2
; U
L3
U
O
for star connection
or
U
12
; U
23
; U
21
for delta connection
and
i
L1
, i
L2
, i
L3
, i
E
,
are scanned at a raster of 1.25 ms (at 50 Hz) and 1.041 ms (at 60 Hz) and saved in a cyclic buffer.
The max. total recording times are 20 s (at 50 Hz) and 16.66s (at 60 Hz).
This only applies to unit versions MRG3 and MRG3-U0. The recording time of all other unit types is
10 s at 50 Hz and 8.33 s at 60 Hz.
Storage division
Independent of the recording time, the entire storage capacity can be divided into several cases of
disturbance with a shorter recording time each. In addition, the deletion behavior of the fault re-
corder can be influenced.
No writing over
If 2, 4 or 8 recordings are chosen, the complete memory is divided into the relevant number of par-
tial segments. If this max. number of fault event has been exceeded, the fault recorder blocks any
further recordings in order to prevent that the stored data are written over. After the data have been
read and deleted, the recorder to ready again for further action.
Writing over
If 1, 3 or 7 recordings are chosen, the relevant number of partial segments is reserved in the com-
plete memory. If the memory is full, a new recording will always write over the oldest one.
When there is no more storage capacity left, the LED FR starts flashing.
The memory part of the fault recorder is designed as circulating storage. In this example 7 fault
records can be stored (written over).
Memory spaces 6
– 4 are occupied
Memory space 5 is just being written over
Figure 4.13: Division of the memory into 8 segments, for example
Since memory spaces 6, 7 and 8 are occupied, this example shows that the memory has been as-
signed more than eight recordings. This means that No. 6 is the oldest fault recording and No. 4
the most recent one.
