Alstom MiCOM P846, Technical Manual

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Measurements and Recording P846/EN MR/D
MiCOM P846
(MR) 8-3
MR
1. MEASUREMENTS AND RECORDING
1.1 Introduction
The P846 is equipped with integral measurements, event, fault and disturbance recording
facilities suitable for analysis of complex system disturbances.
The relay is flexible enough to allow for the programming of these facilities to specific user
application requirements and are discussed below.
1.2 Event & fault records
The relay records and time tags up to 512 events and stores them in non-volatile (battery
backed up) memory. This enables the system operator to establish the sequence of events
that occurred within the relay following a particular power system condition, switching
sequence etc. When the available space is exhausted, the oldest event is automatically
overwritten by the new one.
The real time clock within the relay provides the time tag to each event, to a resolution of
1ms.
The event records are available for viewing either via the frontplate LCD or remotely, via the
communications ports (courier and MODBUS versions only).
Local viewing on the LCD is achieved in the menu column entitled "VIEW RECORDS". This
column allows viewing of event, fault and maintenance records and is shown the following
table:
VIEW RECORDS
LCD Reference Description
Select Event
Setting range from 0 to 511. This selects the required event
record from the possible 512
that may be stored. A value of
0 corresponds to the latest event and so on.
Time & Date
Time & Date Stamp for the event given by the internal Real
Time Clock.
Event Text
Up to 16 Character description of the Event refer to following
sections).
Event Value
Up to 32 Bit Binary Flag or integer representative of the
Event (refer to following sections).
Select Fault
Setting range from 0 to 4. This selects the required fault
record from the possible 5 that may be stored. A value of 0
corresponds to the latest fault and so on.
The following cells show all the fault flags, protection starts,
protection trips, fault location, measurements etc. associated
with the fault, i.e. the complete fault record.
Select Maint.
Setting range from 0 to 4. This selects the required
maintenance report from the possible 5 that may be stored.
A value of 0 corresponds to the latest report and so on.
Maint. Text
Up to 16 Character description of the occurrence (refer to
following sections).
Maint. Type/Main Data
These cells are numbers representative of the occurrence.
They form a specific error code which should be quoted in
any related correspondence to Report Data.
Reset Indication
Either Yes or No. This serves to reset the trip LED
indications provided that the relevant protection element has
reset.