Siemens siprotec 7SA522 - Page 416

3 Mounting and Commissioning
416
7SA522 Manual
C53000-G1176-C155-3
necessary because the polarity is irrelevant here. The voltage magnitude was
checked before.
If the input U
4
is used for the measurement of the displacement voltage U
en
(36\VWHP'DWD Address  8WUDQVIRUPHU = 8GHOWDWUDQVI), the po-
larity together with the current measurement is checked (see in the following).
If the input U
4
is used for measuring a busbar voltage for synchronism check
(36\VWHP'DWD Address  8WUDQVIRUPHU = 8V\QFWUDQVI), the po-
larity must be checked as follows using the synchronism check function.
Only for Synchro-
nism Check
The device must be equipped with the synchronism and voltage check function which
must be configured under address  (QDEOHG (see section 2.1.1.2).
The voltage connected to the busbar must be specified correctly under address 
8V\QFFRQQHFW (see Subsection 2.1.3.1).
If there is no transformer between the two measuring points, address  ϕ8V\QF
8OLQH must be set to ° (see Subsection 2.1.3.1).
If the measurement is made across a transformer, this angle setting must correspond
to the phase rotation through which the vector group of the transformer as seen from
the feeder in the direction of the busbar rotates the voltage. An example is shown in
Subsection 2.1.3.1.
If necessary, different transformation ratios of the transformers on the busbar and the
feeder may have to be considered under address  8OLQH8V\QF.
The synchronism and voltage check must be switched 21 under address  )&7
6\QFKURQLVP .
An additional help for the connection control are the messages 2947 ´6\QF
8GLII!µ and 2949 ´6\QFϕGLII!µ in the spontaneous annunciations.
• Circuit breaker is open. The feeder is isolated (zero voltage). The VTmcb's of both
voltage transformer circuits must be closed.
• For the synchronism check the program 29(55,'( = <(6 (Address ) is set;
the other programs (Addresses  to ) are set to 12.
• Via binary input (FNo. 2906 ´!6\QF6WDUW$5µ) initiate the measuring request.
The synchronism check must release closing (message ´6\QFUHOHDVHµ, FNo.
2951). If not, check all relevant parameters again (synchrocheck configured and
enabled correctly, see Sections 2.1.1.2, 2.1.3.1 and 2.14.2).
• Set address  29(55,'( to 12.
• Then the circuit breaker is closed while the line isolator is open (see following Fig-
ure). Both voltage transformers therefore measure the same voltage.
• The program 6<1&&+(&. = <(6 (Address ) is set for synchronism check.
• Via binary input (FNo. 2906´!6\QF6WDUW$5µ) initiate the measuring request.
The synchronism check must release closing (message ´6\QFUHOHDVHµ, FNo.
2951).