Siemens SIPROTEC 7UT613 series Manual page 393

Voltage Functions
7UT613/63x Manual
C53000-G1176-C160-2
• If the current function is assigned to a measured location and the pickup values are
set primary, the setting value is to be converted to secondary value, so that the
pickup value at the secondary test current is maintained. For the conversion the
transformation of the current transformer (set for this device measuring input) is im-
portant.
• Tests for positive and negative sequence system currents are easiest with three-
phase symmetrical testing. The positive sequence system can be obtained by sym-
metrical test currents, the negative sequence system by exchanging two phases.
The setting values I1 and I2 correspond to the magnitude of each test current. For
single-phase testing the positive and negative sequence currents are
current.
• Testing the zero system can be done single-phase at any of the three-phase current
inputs. Zero sequence current is set to 3 · I
must-pickup value.
For flexible functions with Voltage Detection the test voltages are fed to into the single-
phase or to the voltage measuring inputs. This is also valid for the frequency function.
A symmetrical three-phase voltage source is recommended. If testing takes place with
a single-phase current source, special considerations are applicable, which will still be
given. For functions working on exceeding voltages slowly increased test voltage is
applied until the function trips. Value undershooting above a pickup value it is de-
creased. Keep in mind that the corresponding message can be delayed if a time delay
is set.
Caution!
Tests with voltages that exceed more than 170 V at the voltage input terminals cause
an overload of the input circuits and may only be performed for a short time.
See Technical Data
Afterwards the device has to cool off!
When checking pickup values keep in mind:
• Valid for all voltages is that the secondary settings are done in volts. If primary
values were set, these are to be converted to secondary values via the voltage
transformer data.
• If a single voltage, monitored by the flexible function, is to be tested, check the
voltage measuring input in single-phase.
• If the phase-to-earth voltages important, do the testing at the three-phase voltage
measuring inputs; this can be done three-phase or single-phase (after each other
for every phase). When testing for voltage decrease the not tested voltages have to
lie above the pickup value, so that triggering can be prevented.
• If the phase-to-phase voltages are important, three-phase testing is recommended.
Otherwise make sure that the test voltage lies above both measuring inputs for the
connected voltage. When testing voltage decrease the not tested phase must
receive a sufficiently high voltage, so that the voltages connected to it lie above the
pickup value.
3.3 Commissioning
, the test current corresponds to the
0
1
/ of the test
3
393