Testing User-Defined Functions; Current, Voltage, And Phase Rotation Testing - Siemens 7SC80 Manual

Testing User-Defined Functions

3.3.6
CFC Logic
The device has a vast capability for allowing functions to be defined by the user, especially with the CFC logic.
Any special function or logic added to the device must be checked.
Of course, general test procedures cannot be given. Configuration of these functions and the target conditions
must be actually known beforehand and tested. Possible interlocking conditions of switching devices (circuit
breakers, disconnectors, ground switch) are of particular importance. They must be observed and tested.

Current, Voltage, and Phase Rotation Testing

3.3.7
Preliminary Remark
NOTE
i
i
The voltage and phase rotation test is only relevant for devices with voltage transformers.
≥ 10 % of Load Current
The connections of the current and voltage transformers are tested using primary quantities. Secondary load
current of at least 10 % of the nominal current of the device is necessary. The line is energized and will remain
in this state during the measurements.
With proper connections of the measuring circuits, none of the measured-values supervision elements in the
device should pick up. If an element detects a problem, the causes which provoked it may be viewed in the
Event Log. If current or voltage summation errors occur, then check the matching factors.
Messages from the symmetry monitoring could occur because there actually are asymmetrical conditions in
the network. If these asymmetrical conditions are normal service conditions, the corresponding monitoring
functions should be made less sensitive.
Current and Voltage Values
Currents and voltages can be read out via a PC using the Web Monitor or the operator interface, and compared
with the actual measured quantities, as primary and secondary quantities.
If the measured values are not plausible, the connection must be checked and corrected after the line has
been isolated and the current transformer circuits have been short-circuited. The measurements must then be
repeated.
NOTE
i
i
If the voltage measurement is carried out via feed through capacitances, the display of the values of the
phaseto- ground voltages and phase angle between the phase-to-ground voltages and the phase currents
can be used to optimize the configured capacitance values afterwards and to achieve an improvement of
the measuring accuracy. An explanation of the procedure for optimizing the input capacitances is to be
found in Section
Phase Rotation
The phase rotation must correspond to the configured phase rotation, in general a clockwise phase rotation. If
the system has an anti-clockwise phase rotation, this must have been considered when the power system data
was set (address 209 PHASE SEQ.). If the phase rotation is incorrect, the alarm
is generated. The measured value phase allocation must be checked and corrected, if required, after the line
has been isolated and current transformers have been short-circuited. The measurement must then be
repeated.
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
2.1.3.2 Setting Notes, "Capacitive Voltage Measurement".
Mounting and Commissioning
3.3 Commissioning
Fail Ph. Seq. (FNo 171)
487