Circuit Breaker (Cb) - Siemens 7SR10 Argus Series Manual

4.4

Circuit Breaker (CB)

This menu includes relay settings applicable to both manual close (MC) and auto-reclose (AR) functionality.
'CB Failed To Open' and 'CB Failed to Close' features are used to confirm that a CB has not responded correctly
to each Trip and Close Command. If a CB fails to operate, the DAR feature will go to lockout.
Close CB Pulse
The duration of the CB Close Pulse is settable to allow a range of CBs to be used. . The Close CB Pulse must
be long enough for the CB to physically close.
The Close pulse will be terminated if any protection pick-up operates or a trip occurs. This is to prevent Close and
Trip Command pulses existing simultaneously. A 79 Close Onto Fault output is given if a pick-up or trip operates
during the Close Pulse. This can be independently wired to Lockout.
The output CB Fail to Close is issued if the CB is not closed at the end of the close pulse, Close CB Pulse.
Reclaim Timer
The 'Reclaim time' will start each time a Close Pulse has timed out and the CB has closed.
Where a protection pickup is raised during the reclaim time the relay advances to the next part of the reclose
sequence.
The relay goes to the Lockout state if the CB is open at the end of the reclaim time or a protection operates during
the final reclaim time.
CB Control Trip Time
When this is set to Enabled, the relay will measure the CB trip time following operation of either a CB control
open output or a CB Trip output. The trip time is displayed by the MAINTENANCE METERS > CB Trip Time
meter.
When this is set to Disabled, the relay will measure the trip time following operation of a CB Trip output only.
Operation of a CB control open output will then not cause the trip time to be measured.
Open CB Pulse
The duration of the CB open pulse is user settable to allow a range of CBs to be used.
The CB open pulse must be long enough for the CB to physically open.
CB Travel Alarm
The CB Open and CB Closed binary inputs are continually monitored to track the CB Status.
The CB should only ever be in 3 states:
CB Status
CB is Open
CB is Closed
CB is Travelling between the above 2 states
The Relay goes to Lockout and the CB Alarm output is given where the Travelling condition exists for longer than
the CB Travel Alarm setting.
An instantaneous CB Alarm is given for a 1/1 state – i.e. where the CB indicates it is both Open and Closed at
the same time.
CB DBI Delay
The CB Open and CB Closed binary inputs are continually monitored to track the CB Status.
A Don't Believe it (DBI) condition exists for a 1/1 state– i.e. where the CB indicates it is both Open and Closed at
the same time
©2018 Siemens Protection Devices Limited
7SR10 Description of Operation
CB Open
binary input
1
0
0
Chapter 1 Page 60 of 77
CB Closed binary
input
0
1
0