Mounting and Commissioning
3.3 Commissioning
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
338
Current and Voltage Values
Currents and voltages can be seen in the display field on the front of the device or the operator interface via a
PC. They can be compared to the quantities measured by an independent source, 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 re-
peated.
Note
If the voltage measurement is carried out via feed through capacitances, the display of the values of the phase-
to-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 measur-
ing accuracy. An explanation of the procedure for optimizing the input capacitances is to be found in Section
2.1.3.2, „Capacitive Voltage Measurement“.
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 „Fail Ph. Seq.“ (FNo
171) 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 re-
peated.
Voltage Transformer Miniature Circuit Breaker (VT mcb)
The VT mcb of the feeder (if used) must be opened. The measured voltages in the operational measured
values appear with a value close to zero (small measured voltages are of no consequence).
Check in the spontaneous annunciations that the VT mcb trip was entered (annunciation „>FAIL:FEEDER
VT“ „ON“ in the spontaneous annunciations). Beforehand it has to be assured that the position of the VT mcb
is connected to the device via a binary input.
Close the VT mcb again: The above messages appear under the spontaneous messages as „OFF“, i.e.
„>FAIL:FEEDER VT“ „OFF“.
If one of the events does not appear, the connection and allocation of these signals must be checked.
If the „ON“-state and „OFF“–state are swapped, the contact type (H–active or L–active) must be checked and
remedied.
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