ABB REU 523 - Control and Indication of Disturbance Recorder Status

1MRS 750942-MUM
Combined Overvoltage and Undervoltage Relay
Technical Reference Manual
REU 523
31
The recording length varies according to the selected sampling frequency. The RMS
curve is recorded by selecting the sampling frequency to be the same as the nominal
frequency of the relay. The sampling frequency is selected with parameter M15; see
the table below for details.
1)
RMS curve.
Recording length:
Changing the setting values of parameter M15 is allowed only when the recorder has
not been triggered.
The post-triggering recording length defines the time during which the recorder
continues to store data after it has been triggered. The length can be changed with
parameter V240. If the post-triggering recording length has been defined to be the
same as the total recording length, no data stored prior to the triggering will be
retained in the memory. By the time the post-triggering recording finishes, a
complete recording will have been created.
Triggering of the recorder immediately after it has been cleared or the auxiliary
voltage connected may result in a shortened total recording length. Disconnection of
the auxiliary voltage after the recorder has been triggered but before the recording
has finished, on the other hand, may result in a shortened post-triggering recording
length. This, however, will not affect the total recording length.
At a power reset, triggered recorder data will be retained in the memory provided
that it has been defined non-volatile.
4.1.8.3. Control and indication of disturbance recorder status
It is possible to control and monitor the recording status of the disturbance recorder
by writing to and reading parameters M1, M2 and V246. Reading parameter V246
will return either the value 0 or 1, indicating whether the recorder has not been
triggered or triggered and ready to be uploaded. Event code E31 will be generated
the moment the disturbance recorder has been triggered. If the recorder is ready to
be uploaded, this will also be indicated by an asterisk shown in the lower
right-hand corner of the LCD when it is in the idle mode.
Table 4.1.8.2-1 Sampling frequency
Nominal frequency
Hz
Sampling frequency
Hz
Cycles
50 800 40
400 80
50
1)
640
60 960 40
480 80
60
1)
640
s[]
Cycles
Nominal frequency Hz[]
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