Siemens siprotec SJ62 User Manual page 430

Current and Voltage
Values
Phase Rotation
Voltage Transform-
er Miniature Circuit
Breaker (VT mcb)
Only 7SJ64
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
is necessary. The line is energized and will remain in this state during the measure-
ments.
With proper connections of the measuring circuits, none of the measured-values su-
pervision 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 sum-
mation 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 sen-
sitive.
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 correct-
ed after the line has been isolated and the current transformer circuits have been
short-circuited. The measurements must then be repeated.
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 repeated.
The VT mcb of the feeder (if used) must be opened. The measured voltages in the op-
erational measured values appear with a value close to zero (small measured voltag-
es are of no consequence).
Check in the spontaneous annunciations that the VT mcb trip was entered (annunci-
ation „>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 mes-
sages 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.
If with 7SJ64 a busbar voltage is used for input V
and the assigned VT mcb is connected to the device, the following function must also
be checked: If the VT mcb is open the annunciation „>FAIL: BUS VT" „ON" ap-
pears, if it is closed the annunciation „>FAIL: BUS VT" „OFF" is displayed.
If the VT mcb is open the annunciation „>FAIL: BUS VT" „ON" appears, if it is closed
the annunciation „>FAIL: BUS VT" „OFF" is displayed.
Switch off the protected power line.
3.3 Commissioning
(for voltage or synchronism check)
4
428