Section 6: Other Features; Data Communications; Cb Maintenance; 6.2.1 Output Matrix Test - Siemens 7SR21 Manual

Section 6: Other Features

6.1

Data Communications

Two communication ports, COM1 and COM2 are provided. RS485 connections are available on the terminal
blocks at the rear of the relay (COM1). A USB port, COM 2, is provided at the front of the relay for local access
using a PC.
Optionally, additional communication ports are available: -
2x fibre optic with ST connectors and 1x IRIG-B – (COM3 and COM4),
1x RS485 and 1x IRIG-B – (COM3),
1x RS232 and IRIG-B – (COM3)
Communication is compatible with Modbus-RTU, IEC60870-5-103 FT 1.2 and DNP 3.0 transmission and
application standards.
For communication with the relay via a PC (personal computer) a user-friendly software package, Reydisp
Evolution, is available to allow transfer of relay settings, waveform records, event records, fault data records,
Instruments/meters and control functions. Reydisp Evolution is compatible with IEC60870-5-103.
Data communications operation is described in detail in Chapter 4 of this manual.
6.2

CB Maintenance

Several CB operations counters are provided:
CB Total Trip Count:
CB Delta Trip Count:
CB Count to AR Block:
CB Frequent Ops Count
2
An I t counter is also included, this can provide an estimation of contact wear and maintenance requirements. The
algorithm works on a per phase basis, measuring the arcing current during faults. The I
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.
Binary outputs can be mapped to each of the above counters, these outputs are energised when the user defined
Count Target or Alarm Limit is reached.

6.2.1 Output Matrix Test

The feature is only visible from the Relay fascia and allows the user to operate the relays functions. The test of
the function will automatically operate any Binary Inputs or LED's already assigned to that function. Any
protection function which is enabled in the setting menu will appear in the Output Matrix Test.
©2010 Siemens Protection Devices Limited
7SR21 & 7SR22 Argus Description of Operation
Increments on each trip command issued. During an auto-
reclose sequence, if the target count is reached the relay will
perform one Delayed Trip and lockout.
Additional counter which can be reset independently of the
Total Trip Counter. This can be used, for example, for
recording trip operations between visits to a substation.
Displays the number of CB trips experienced by the CB.
When the target is reached the relay will only do 1 Delayed
Trip to Lockout.
Logs the number of trip operations in a rolling window period
of one hour. During an auto-reclose sequence, if the target
count is reached the relay will perform one Delayed Trip and
lockout.
2
t value at the time of trip
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