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3.4 Recording Function
The GRD150 is provided with the following recording functions:
Fault recording
Alarm recording
Event recording
Disturbance recording
Counters
These records are displayed on the LCD of the relay front panel or on the local or remote PC.
3.4.1
Fault Recording
Fault recording is started by any of a tripping command of the GRD150 and start commands
"2624:F.RECOD1" to "2627:FRECORD4" by PLC, and the following items are recorded for one
fault:
Date and time
Trip mode
Operating phase
Fault location
Relevant events
Power system quantities
Up to the 8 most-recent faults are stored as fault records. If a new fault occurs when 8 faults have
been stored, the record of the oldest fault is deleted and the record of the latest fault is then stored.
Date and time occurrence
This is the time at which a tripping command or a start command by PLC has been initiated.
The time resolution is 1 ms using the relay internal clock.
Trip mode
This shows the protection scheme such as DOC1, DEF1, OC1 etc. that output the tripping
command.
Operating phase
This is the phase to which a tripping command is output.
Fault location
The distance to the fault point calculated by the fault locator is recorded.
The distance is expressed in km and as a percentage (%) of the line length.
Relevant events
Such events as autoreclose, re-tripping following the reclose-on-to-a fault or autoreclose and
tripping for evolving faults are recorded with time-tags.
Power system quantities
The following power system quantities in pre-faults and post-faults are recorded.
- Magnitude and phase angle of phase voltage (V a , V b , V c )
⎯
⎯
136
6 F 2 S 0 8 4 2
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