Siemens siprotec 7SA522 User Manual

Functions
6-77SA522 Manual
C53000-G1176-C119-2
6.1.1 Power System Data 1
Some system and plant data are required by the device, so that it may adapt its func-
tions to these data, according to its mode of operation. Amongst others, the plant and
instrument transformer ratings, polarity and termination of the measured values, pa-
rameters of the circuit breaker, etc. These data are summarized in 3RZHU6\VWHP
'DWD36\VWHP'DWD.
If the key is operated, the main menu is displayed. With the key the option 6HW
WLQJV is selected and by pushing the key the selection of 6HWWLQJVis con-
firmed. To enter the plant data 3RZHU6\VWHP'DWD36\VWHP'DWD must
be selected in the menu 6HWWLQJV.
With DIGSI
®
4 the corresponding selection is reached by double click on 6HWWLQJV.
Polarity of Current
Transformers
In address  &76WDUSRLQW the polarity of the current transformers must be en-
tered, in other words, the location of the CT star-point (Figure 6-8). This setting deter-
mines the measuring direction of the device (forward = line direction). A change of this
parameter also results in the polarity reversal of the earth current input.
Figure 6-8 Current transformer polarity
Instrument Trans-
former Nominal
Values
In the address  8QRP35,0$5< and  8QRP6(&21'$5< the device is in-
formed of the primary and secondary rated voltage (line voltage) of the voltage trans-
formers. In the address  &735,0$5< and  &76(&21'$5< the primary
and secondary rated current (phase current) of the current transformers are entered.
Please observe that the rated current transformer secondary current must corre-
sponds to the rated current of the device, as the device would otherwise compute in-
correct primary data.
Correct entry of the primary data is a prerequisite for the correct computation of oper-
ational measured values with primary magnitude. If DIGSI
®
4 is used to enter param-
eters as primary quantities, the correct entry of the primary data is an important pre-
requisite for the correct operation of the device.
Voltage Trans-
former Connection
The device contains four voltage measuring inputs, three of which are connected to
the set of voltage transformers. For the fourth voltage transformer U
4
input several op-
tions are available:
• Connection of the U
4
input to the open delta connection e–n of a set of voltage
transformers, refer to appendix A, Figure 1-14:
Address  is then set to: 8WUDQVIRUPHU = 8GHOWDWUDQVI.
MENU
I
L1
I
L2
I
L3
I
N
I
L1
I
L2
I
L3
I
N
%XV
$GGUHVV
WRZDUGV/LQH
/LQH
/LQH
$GGUHVV
WRZDUGV%XVEDU

Siemens siprotec 7SA522 Specifications

General

Brand	Siemens
Model	siprotec 7SA522
Category	Protection Device
Language	English