Areva MiCOM P921, Technical Manual

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Technical Guide P92x/EN FT/E11
User Guide
MiCOM P921-P922-P923 Page 87/110
VC MAGNITUDE
xxxxxx
Description : magnitude of the phase C voltage at the instant
of the fault (or Vca according to the connection scheme)
Note : read only, no modifications allowed.
V0 MAGNITUDE
xxxxxx
Description : magnitude of the residual voltage at the instant of
the fault (if residual VT connected)
Note : read only, no modifications allowed.
12.3 "DISTURB RECORDER" Menu
12.3.1 Description
Disturbance records are stored in the non-volatile memory. A total of 5 such records
are stored, each of duration 2.5 seconds.
The pre-trigger and post-trigger times can be set in this sub-menu : the total time will
be equal to 2.5s. The pre-time will be priority.
When the available record space is exhausted, the relay will automatically overwrite
the oldest record, to accomodate the new record.
The acquisition frequency for the disturbance recorder is 32 samples per cycle of the
power system frequency .
Disturbance records can be extracted either automatically (rear port only) or manually
(front or rear port).
The recording of the disturbance data can be triggered by any instantaneous
information, any time-delayed information, activation of a logic input or a logic
equation.
12.3.2 HMI description
To gain access to the “DISTURB RECORDER” sub-menu from the default display,
press 2 once, 4 once, 2 once and 6 twice
.
DISTURB RECORDER
Heading of the “DISTURB RECORDER” sub-menu
PRE-TIME
0.1 s
Description : setting of the pre-trigger time
Range : 0.1 – 2.5s, step = 0.01s
POST-TIME
0.1 s
Description : setting of the post-trigger time
Range : 0.1 – 2.5s, pas = 0.01s
DISTURB REC TRIG
ON INST
Description : selection of the trigger mode
Range : ON INST / ON TRIP