Checking The Voltage Connections And Polarity Check - Siemens SIPROTEC 7UT613 series Manual

3 Mounting and Commissioning

3.3.12 Checking the Voltage Connections and Polarity Check

Voltage and Phase
Sequence Check
412
been checked as a starpoint current input of the main protected object, an additional
check of this 1-phase input must be carried out.
The test methods depend widely on the application of the single-phase input.
By any means, the matching factors for the magnitude have to be checked (address
712, 713 etc. depending on the input under test; refer also to Subsection 2.1.4 under
margin heading „Current Transformer Data for 1-phase Auxiliary Current Inputs").
Consider whether or not the input under test is a high-sensitivity input (address 255
or 256 for I
for I
, refer to subsection 2.1.4 under margin heading „High-Sensitivity
X3 X4
Auxiliary 1-phase Measuring Locations"). Where applicable, consider the matching
factors (addresses 734 and 744 respectively) when reading out the current magni-
tudes.
Polarity check is not required since only the current magnitude is processed.
With high-impedance protection the assigned 1-phase current corresponds to the fault
current in the protected object. Polarity of all current transformers supplying the resis-
tor whose current is measured must be uniform. For this purpose, traversing currents
are used as for differential protection checks. Each current transformer must be in-
cluded into a measurement. The measured current must not exceed, for each through-
current test, half of the pickup value of the single-phase time overcurrent protection.
If the device is connected to voltage transformers, these connections are checked
using primary values. For devices without voltage transformer connection this section
can be bypassed.
The voltage transformer connections are tested for that measuring location or side to
which they are assigned (address 261, refer to Section 2.1.4 under margin heading
„Assignment of Voltage Measuring Inputs").
• Having energised the voltage transformer set, none of the measurement monitoring
functions in the device may respond.
– If there is a fault annunciation, however, the event log or spontaneous annunci-
ation could be checked to investigate the reason for it.
– At the indication of voltage summation error check also the assignment of the
single-phase voltage input and the matching factors. For further details see
Section 2.1.4 under margin heading „Assignment of Voltage Measuring Inputs".
– At the indication of symmetry monitoring there might actually be asymmetries of
the primary system. If they are part of normal operation, the corresponding mon-
itoring function is set less sensitive (see Subsection 2.19.1.4 under margin
heading „Voltage Balance").
7UT613/63x Manual
C53000-G1176-C160-2