Waveform Records; Fault Records; Metering - Siemens 7SR21 Manual

6.3.4

Waveform Records.

Relay waveform storage can be triggered either after user selected relay operations, from the relay fascia, from a
suitably programmed binary input or via the data comms channel(s). The stored analogue and digital waveforms
illustrate the system and relay conditions at the time of trigger.
In total the relay provides 10 seconds of waveform storage, this is user selectable to either 1 record of 10 seconds
duration, 2 records of 5 seconds duration, 5 records of 2 seconds duration or 10 records of 1 second duration.
When the waveform recorder buffer is full any new waveform record will over-write the oldest. The most recent
record is Waveform 1.
As well as defining the stored waveform record duration the user can select the percentage of the waveform
storage prior to triggering.
Waveforms are sampled at a rate of 1600Hz.
Stored waveforms can be erased using the DATA STORAGE>Clear Waveforms setting, or using Reydisp
Evolution via Relay > Waveform > Reset Waveform Records.
6.3.5

Fault Records

Up to ten fault records can be stored and displayed on the Fascia LCD.
Fault records provide a summary of the relay status at the time of trip, i.e. the element that issued the trip, any
elements that were picked up, the fault type, LED indications, date and time. The Max Fault Rec. Time setting
sets the time period from fault trigger during which the operation of any LEDs is recorded.
The relay can be set to automatically display the fault record on the LCD when a fault occurs by enabling the
SYSTEM CONFIG> Trip Alert setting. When the trip alert is enabled the fault record will be displayed until the
fault is removed.
When examined together the event records and the fault records will detail the full sequence of events leading to
a trip.
Fault records are stored in a rolling buffer, with the oldest faults overwritten. The fault storage can be cleared with
the DATA STORAGE>Clear Faults setting or using Reydisp Evolution via Relay > Data Records > Reset Data
Log Record.
6.4

Metering

The metering feature provides real-time data available from the relay fascia in the 'Instruments Mode' or via the
data communications interface.
The Primary values are calculated using the CT and VT ratios set in the CT/VT Config menu.
The text displayed in the relays 'Instruments Mode' associated with each value can be changed from the default
text using the Reydisp software tool.
The user can add the meters that are most commonly viewed to a 'Favourites' window by pressing 'ENTER' key
when viewing a meter.
Config/Favourite Meters Timer menu.
For a detailed description refer to Technical Manual Chapter 2 – Settings and Instruments.
©2010 Siemens Protection Devices Limited
The relay will scroll through these meters at an interval set in the System
7SR21 & 7SR22 Argus Description of Operation
Chapter 1 Page 68 of 71