Measurements and Recording P746/EN MR/A11
MiCOM P746 (MR) 8-
3
MR
1. MEASUREMENTS AND RECORDING
1.1 Introduction
The P746 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 front plate LCD or remotely, via the
communications port.
Local viewing on the LCD is achieved in the menu column entitled "VIEW RECORDS". This
column allows viewing of event, fault and maintenance records.
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.
Menu Cell Ref
Latched alarm active, Latched alarm inactive, Self reset
alarm active, Self reset alarm inactive, Relay contact event,
Opto-isolated input event, Protection event, General event,
Fault record event, Maintenance record event
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.
Faulted Phase Phase initiating fault recorder starts : Start A, Start B, Start
C, Start N, Trip A, Trip B, Trip C, Trip N
Start Elements1 Id Bias Start A, Id Bias Start B, Id Bias Start C, DeadZone 1
Start, DeadZone 2 Start, DeadZone 3 Start, DeadZone 4 Start,
DeadZone 5 Start, DeadZone 6 Start, DeadZone 7 Start,
DeadZone 8 Start, DeadZone 9 Start, DeadZone10 Start,
DeadZone11 Start, DeadZone12 Start, DeadZone13 Start,
DeadZone14 Start, DeadZone15 Start, DeadZone16 Start,
DeadZone17 Start, DeadZone18 Start, T1 I>1 Start, T1 I>2
Start, T2 I>1 Start, T2 I>2 Start, T3 I>1 Start, T3 I>2 Start, T4
I>1 Start, T4 I>2 Start, T5 I>1 Start, T5 I>2 Start, T6 I>1 Start
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