Tests For Circuit Breaker Failure Protection - Siemens siprotec SJ62 User Manual

Exiting the Test
Mode
3.3.4

Tests for Circuit Breaker Failure Protection

General
Auxiliary Contacts
of the CB
External Initiation
Conditions
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
To end the hardware test, click on Close. The dialog box closes. The device becomes
unavailable for a brief start-up period immediately after this. Then all hardware com-
ponents are returned to the operating conditions determined by the plant settings.
If the device provides a breaker failure protection and if this is used, the integration of
this protection function in the system must be tested under practical conditions.
Due to the variety of application options and the available system configurations, it is
not possible to make a detailed description of the necessary tests. It is important to
observe local conditions and protection and system drawings.
Before starting the circuit breaker tests it is recommended to isolate the circuit breaker
of the tested feeder at both ends, i.e. line isolators and busbar isolators should be
open so that the breaker can be operated without risk.
Caution!
Also for tests on the local circuit breaker of the feeder a trip command to the surround-
ing circuit breakers can be issued for the busbar.
Non–observance of the following measure can result in minor personal injury or prop-
erty damage.
Therefore, primarily it is recommended to interrupt the tripping commands to the ad-
jacent (busbar) breakers e.g. by inrupting the corresponding pickup voltage supply.
Before the breaker is finally closed for normal operation, the trip command of the
feeder protection routed to the circuit breaker must be disconnected so that the trip
command can only be initiated by the breaker failure protection.
Although the following lists do not claim to be complete, they may also contain points
which are to be ignored in the current application.
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.
If the breaker failure protection can be started by external protection devices, the ex-
ternal start conditions must be checked.
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.
• Start by trip command of the external protection: binary input functions „>50BF
ext SRC" (FNo 1431) (in spontaneous or fault annunciations).
• After every start, the message „50BF ext Pickup" (FNo 1457) must appear in
the spontaneous or fault annunciations.
• After time expiration TRIP-Timer (address 7005) tripping command of the circuit
breaker failure protection.
Switch off test current.
3.3 Commissioning
426