Siemens 7SC80 Manual page 486

Mounting and Commissioning
3.3 Commissioning
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.
Auxiliary Contacts of the CB
The circuit breaker auxiliary contact(s) form an essential part of the breaker failure protection 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 be started by external protection devices, the external 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
(in spontaneous or fault annunciations).
•
After every start, the message
annunciations.
•
After time expiration TRIP-Timer (address 7005) tripping command of the breaker failure protection.
Switch off test current.
If start is possible without current flow:
•
Closing the circuit breaker to be monitored to both sides with the disconnector switches open.
•
Start by trip command of the external protection: Binary input functions
spontaneous or fault annunciations).
•
After every start, the message
annunciations.
•
After time expiration TRIP-Timer (address 7005) tripping command of the breaker failure protection.
Open the circuit breaker again.
Busbar Tripping
For testing the distribution of the trip commands in the substation in the case of breaker failures it is impor-
tant to check that the trip commands to the adjacent circuit breakers are correct.
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 therefore 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 adjacent circuit breakers largely
depends on the system topology.
In particular with multiple busbars, the trip distribution logic for the adjacent circuit breakers must be checked.
Here it should be checked for every busbar section that all circuit breakers which are connected to the same
busbar section as the feeder circuit breaker under observation are tripped, and no other breakers.
Termination
All temporary measures taken for testing must be undone, e.g. especially switching states, interrupted trip
commands, changes to setting values or individually switched off protection functions.
486
50BF ext Pickup (FNo 1457) must appear in the spontaneous or fault
50BF ext Pickup (FNo 1457) must appear in the spontaneous or fault
>50BF ext SRC (FNo 1431)
>50BF ext SRC (FNo 1431) (in
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017