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5.5 Disturbance Recorder
The disturbance recorder can be initiated by starting, tripping, input or remote (disturbance). The
total disturbance recording time is 6 records of 3 seconds, or 4 × 4s, or 3 × 5s, or 2 × 7s or 1 × 9s.
When the available memory space is used up, the new record automatically overwrites the oldest
record.
The pre-time is the length of time before the disturbance. For example if the pre-time time is set to
100ms, the record starts 100 ms before the disturbance.
Note: Changing the record length and number will result in deletion of existing records. If
necessary, read all wanted records before making changes.
The recorder stores actual samples that are taken at a rate of 32 samples per cycle. Each disturbance
record consists of 5 analogue and 7 digital channels.
5.6 Autoreclose
Autoreclose is used for clearing transient/non-permanent fault. Autoreclose can minimize power
blackout time and reduces the time and costs required for site servicing. With autoreclose,
instantaneous protection can be used, which shorten the time to clear a fault and minimize damages
and to reduce the number of permanent faults.
For recloser to function, the following setting is required:
1.
One of the digital input function is
CB Status 52A
.
2.
One of the output relay function is start/other, CB Close is assigned and reset method is auto
(unlatched)
3.
Output Relay 1 (trip) reset method is auto (unlatched).
4.
Reclose cycle assigned to phase or earth cycle (>0).
The phase cycle and earth cycle are used to set the number of shots (reclose attempts), recloser can
perform 2, 3 or 4 shot cycle. Dead times can be independently adjusted for each shots. The phase
cycle is applied for tAux1 and tAux2 tripping also.
CYCLE setting (for tI>, tI>>, tI>>>, tIo>, tIo>>, tIo>>>, tAux 1, tAux2):
0: Recloser will move to lock status after tripping.
1: Tripping, followed by reclosing cycle.
2: No trip of pickup.
The dead time starts when the CB has opened (52A input deactivates) and the involved protection
threshold reset. At the end of the relevant dead time, a CB close signal is sent. The reclaim time
starts when the CB has closed (52A input activates). If no tripping after reclaim time elapsed, the
recloser resets (reclose successful).
If tripping operates during reclaim time, the relay either advances to the next shot, or if all the
reclose attempts have been accomplished, the recloser locks out (recloser final trip). The recloser
will not be initiated for any fault during lockout.
CB Fail Alarm
If CB not open or close as expected for 2 seconds during reclose cycle, recloser locks out and CB
Fail alarm generated.
