Siemens siprotec 7SD5 User Manual

3.3 Commissioning
491
7SD5 Manual
C53000-G1176-C169-1
Auxiliary Contacts
of the CB
The circuit breaker auxiliary contact(s) form an essential part of the breaker failure pro-
tection system in case they have been connected to the device. Make sure the correct
assignment has been checked.
External Initiation
Conditions
If the breaker failure protection can also be started by external protection devices, the
external start conditions should be checked. Single-pole or three-pole tripping is pos-
sible depending on the setting of the breaker failure protection. Note that the internal
pole discrepancy supervision or the pole discrepancy supervision of the breaker itself
may lead to a later three-pole trip. Therefore check first how the parameters of the
breaker failure protection are set. See Section 2.20.2, addresses 3901 onwards.
In order for the breaker failure protection to be started, a current must flow at least via
the monitored phase. This may be a secondary injected current.
After every start, the message „BF Start“ (No. 1461) must appear in the spontane-
ous or fault indications.
Only if single-pole starting possible:
• Start by single-pole trip command of the external protection: L1
Binary input functions „>BF Start L1“ and, if necessary, „>BF release“ (in
spontaneous or fault indications). Trip command (dependent on settings).
• Start by single-pole trip command of the external protection: L2
Binary input functions „>BF Start L2“ and, if necessary, „>BF release“ (in
spontaneous or fault indications). Trip command (dependent on settings).
• Start by single-pole trip command of the external protection: L3
Binary input functions „>BF Start L3“ and, if necessary, „>BF release“ (in
spontaneous or fault indications). Trip command (dependent on settings).
• Starting by trip command of the external protection via all three binary inputs L1, L2
and L3:
Binary input functions „>BF Start L1“, „>BF Start L2“ and „>BF Start
L3“ and, if necessary, „>BF release“ (in spontaneous or fault indications). Trip
command three-pole
For three-pole starting:
• Three-pole starting by trip command of the external protection:
Binary input functions „>BF Start 3pole“ and, if necessary, „>BF release“
(in spontaneous or fault indications). Trip command (dependent on settings).
Switch off test current.
If start is possible without current flow:
• Starting by trip command of the external protection without current flow:
Binary input functions „>BF Start w/o I“ and, if necessary, „>BF release“
(in spontaneous or fault indications). Trip command (dependent on settings).
Busbar Tripping The most important thing is the check of the correct distribution of the trip commands
to the adjacent circuit breakers in case of breaker failure.
The adjacent circuit breakers are those of all feeders which must be tripped in order
to ensure interruption of the fault current should the local breaker fail. These are there-
fore the circuit breakers of all feeders which feed the busbar or busbar section to which
the feeder with the fault is connected.
A general detailed test guide cannot be specified, because the layout of the surround-
ing circuit breakers largely depends on the system topology.
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Siemens siprotec 7SD5 Specifications

General

Brand	Siemens
Model	siprotec 7SD5
Category	Relays
Language	English