Siemens 7SR242 - Data Storage and Fault Records

7SR242 Duobias Description Of Operation
©2010 Siemens Protection Devices Limited Chapter 1 Page 49 of 52
the time of trip is added to the previously stored value and an
alarm is given when any one of the three phase running
counts exceeds the set Alarm limit . The t value is the time
between CB contacts separation when an arc is formed,
Separation Time, and the CB Clearance time.
I
2
t CB2 Wear: As CB1
The status of each counter can be viewed in the INSTRUMENTS mode.
Binary outputs can be mapped to each of the above counters, these outputs are energised when the
user defined Alarm Limit is reached.
6.3 Data Storage
6.3.1 General
The relay stores three types of data: relay event records, analogue/digital waveform records and fault records.
Waveform records, fault records and event records are backed up in non-volatile memory and are permanently
stored even in the event of loss of auxiliary d.c. supply voltage.
6.3.2 Event Records
The event recorder feature allows the time tagging of any change of state (Event) in the relay. As an event
occurs, the actual event condition is logged as a record along with a time and date stamp to a resolution of 1
millisecond. There is capacity for a maximum of 5000 event records that can be stored in the relay and when the
event buffer is full any new record will over-write the oldest. Stored events can be erased using the DATA
STORAGE>Clear Events setting.
The following events are logged:
Change of state of Binary outputs.
Change of state of Binary inputs.
Change of Settings and Settings Group
Change of state of any of the control functions of the relay.
All events can be uploaded over the data communications channel(s) and can be displayed in the ‘ReyDisp
Evolution’ package in chronological order, allowing the sequence of events to be viewed. Events are also made
available spontaneously to an IEC 60870-5-103 or Modbus RTU compliant control system.
For a complete listing of events available in each model, refer to Technical Manual Chapter 4 ‘Data Comms’.
6.3.3 Waveform Records.
Relay waveform storage can be triggered from:
• User selected relay operations, this requires the relevant OUTPUT CONFIG>B.O.
CONFIG>Trip Contacts setting to be assigned.
• The relay fascia.
• A suitably programmed binary input.
• The data comms channel(s).
Stored analogue and digital waveforms illustrate the system and relay conditions at the time of trigger.