Siemens SIPROTEC 4 7UT6 Series, Руководство пользователя

Страница: 365 / 684

Message No. Description see
section
Diff CT-IX1:
to
Diff CT-IX4:
5738
to
5741 Differential protection: Magnitude matching factor of the indicated
auxiliary 1-phase measuring location 2.1.4 Power
System Data
1
REF CTstar: 199.2639 Earth fault differential protection 1: Magnitude matching factor of the
starpoint current 2.1.4 Power
System Data
1
REF2 CT-M1: to
REF2 CT-M5: 205.2634 to
205.2638 Earth fault differential protection 2: Magnitude matching factor at the
indicated measuring location 2.1.4 Power
System Data
1
REF2 CTstar: 205.2639 Earth fault differential protection 2: Magnitude matching factor of the
starpoint current 2.1.4 Power
System Data
1
Secondary Tests
Checking the individual protection functions of the characteristic curves or pick-up values is not required since
these are part of the firmware programs which are monitored continuously. Analogue inputs are checked at
the primary commissioning at the protective object (Section
3.3 Commissioning under “Symmetrical Current
Tests on the Protective Object”). Verification of connections, i.e. coupling with the plant, also takes place
there. Measured quantities deviation between the protective functions and phases can be excluded.
Secondary checks can never replace the primary checks described below, as connection errors cannot be
included. They can however be used as theoretical test of the setting values. Should you want to perform a
secondary test, please observe the following hints.
When performing tests with secondary test equipment, attention must be paid that no other measuring values
are applied and that the trip command to the circuit breakers are interrupted.
The tests should be done with the current setting values of the device. If these are not (yet) available, the test
should be done with the preset values.
i
i
NOTE
The measurement accuracy to be achieved depends on the electrical data of the test sources used. The
accuracies specified in the technical specifications can be expected only if the reference conditions in
accordance with VDE 0435/Part 303 or IEC 60255 are adhered to, and precision measurement instruments
are used. The stated tolerances refer to the preset data of the protective object. If the ( reference current
transformer rated current) rated current deviates greatly from the protective object, appropriately high
pickup tolerance has to be used.
Differential Protection
Every side of the differential protection can be checked. This is consistent with the simulation of a single
source error. If a side has several measuring locations, the not in a test involved measured inputs remain at
zero current. Checking the pickup value is performed by slowly increasing the test current.
!
CAUTION
Tests with currents that exceed more than 4 times the rated device current cause an overload of the input
circuits and may only be performed for a short time.
See Technical Data
²
Afterwards the device has to cool off!
3.3.6
Mounting and Commissioning
3.3 Commissioning
SIPROTEC 4, 7UT6x, Manual 365
C53000-G1176-C230-5, Edition 09.2016