Maintenance; Output Matrix Test; Cb Counters; I 2 T Cb Wear - Siemens 7SR18 Solkor Manual

6.3

Maintenance

6.3.1

Output Matrix Test

This 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.
6.3.2

CB Counters

The following CB maintenance counters are provided:
CB Total Trip Count:
CB Delta Trip Count:
CB Frequent Ops Count
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.
2
6.3.3 I t CB Wear
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.
2
The I t value at 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.
2
The I t value can also triggered and reset from a binary input or command.
6.3.4

Start Count

Refer to 2.11 Self Monitoring.
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Increments on each trip command issued.
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.
Logs the number of trip operations in a rolling window period
of one hour. An output is available to reset this counter.
7SR18 Description Of Operation
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