3 Mounting and Commissioning
268
7UM61 Manual
C53000-G1176-C127-3
3.3.4
Testing Circuit Breaker Failure Protection
General
If the device is equipped with the breaker failure protection and this function is used,
its interaction with the breakers of the power plant must be tested in practice.
Especially important for checking the system is the correct distribution of the trip com-
mands to the adjacent circuit breakers in the event of breaker failure.
Adjacent circuit breakers are those which must trip in the event of a breaker failure in
order to cut off the short-circuit current. Therefore these are the circuit breakers that
feed the faulted line.
It is not possible to define a generally applicable, detailed test specification since the
definition of adjacent circuit breakers depends to a large extent of the plant layout.
3.3.5
Testing User-defined Functions
CFC Logic
The device has a vast capability for allowing functions to be defined by the user, es-
pecially with the CFC logic. Any special function or logic added to the device must be
checked.
Naturally, general test procedures cannot be given. Rather, the configuration of these
user defined functions and the necessary associated conditions must be known and
verified. Of particular importance are possible interlocking conditions of the switchgear
(circuit breakers, isolators, etc.).
3.3.6
Trip/Close Tests for the Configured Operating Devices
Control by Local
Command
If the configured operating devices were not switched sufficiently in the hardware test
already described, all configured switching devices must be switched on and off from
the device via the integrated control element. For this the switch position response in-
dications linked in via binary inputs should be read out at the device and compared
with the actual switch position.
The switching procedure is described in the SIPROTEC
®
system description /1/. The
switching authority must be set in correspondence with the source of commands used.
With the switch mode it is possible to select between interlocked and non-interlocked
switching. Note that non-interlocked switching constitutes a safety risk.
DANGER!
A test cycle successfully started by the automatic reclosure function can lead
to the closing of the circuit breaker!
Non-observance of the following statement will result in death, severe personal injury
or substantial property damage.
Be fully aware that OPEN-commands sent to the circuit breaker can result in a trip-
close-trip event of the circuit breaker by an external reclosing device.
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