Siemens SIPROTEC 7SD610, Руководство пользователя

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Mounting and Commissioning
3.3 Commissioning
SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011
311
• Having closed the circuit breaker, none of the measurement monitoring functions in the device must re-
spond.
– If there was a fault indication, however, the Event Log or spontaneous indications could be checked to
investigate the reason for it.
– Indications of symmetry monitoring could occur because there are actually assymmetrial conditions in the
primary system. If they are part of normal operation, the corresponding monitoring function is set less sen-
sitive (see Section 2.15.1 under side title „Symmetry Monitoring“).
The voltages can be read as primary and secondary values on the display at the front, or called up in the
PC via the operator or service interface, and compared with the actual measured quantities. Besides the
magnitudes of the phase-to-earth and the phase-to-phase voltages, the phase differences of the voltages
are also displayed so that the correct phase sequence and polarity of individual transformers can also be
seen. The voltages can also be read with the „WEB-Monitor“ (see below, „Current test“).
• The voltages have to be almost equal. All three angles
ϕ
(U
Lx
–U
Ly
) must be approximately 120°.
– If the measured quantities are not plausible, the connections must be checked and corrected after switch-
ing off the line. If, for example, the phase difference between two voltages is 60° instead of 120°, one
voltage must be polarity-reversed The same applies if there are phase-to-phase voltages which are
almost equal to the phase voltages instead of having a value that is
√
3 larger. The measurements have
to be repeated after correcting the connections.
– In general, the phase rotation is clockwise. If the system has an anti-clockwise phase rotation, this must
be identical at all ends of the protected object. The phase assignment of the measured quantities has to
be checked and, if required, corrected after the line has been switched off. The measurement must then
be repeated.
• Open the circuit breaker for voltage transformers of the feeder. The measured voltages in the operational
measured values appear with a value close to zero (small measured voltages are of no consequence).
– Check the Event Log and the spontaneous indications to make sure that the VT mcb trip was noticed (in-
dication
„>FAIL:Feeder VT“
„ON“, no. 361). This requires the position of the circuit breaker for voltage
transformers to be communicated to the device via a binary input.
• Close the circuit breaker for voltage transformers: The above indication is displayed in the spontaneous in-
dications as „OFF“, i.e.
„>FAIL:Feeder VT“
„OFF“.
– If one of the indications does not appear, the connection and allocation of these signals must be checked.
– If „ON“ state and „OFF“ state are swapped, the contact type (H–active or L–active) must be checked and
corrected.
• The protected object is switched off.
• This check must be performed at both ends.
3.3.8 Checking the Instrument Transformer Connections with Two Line Ends
Current Test
The connections of the current transformers are tested with primary values. A load current of at least 5% of the
rated operational current is required. Any direction is possible.
This test cannot replace the visual inspection of the correct current transformer connections. Therefore, the in-
spection according to Section „Checking the System Connections“ is a prerequisite.