Siemens SIPROTEC 7SJ61 - Measurement; Display of Measured Values

Functions
2.17 Auxiliary Functions
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008
227
2.17.3 Measurement
A series of measured values and the values derived from them are constantly available for call up on site, or
for data transfer.
Applications
• Information on the actual status of the system
• Conversion of secondary values to primary values and percentages
Prerequisites
Except for secondary values, the device is able to indicate the primary values and percentages of the measured
values.
A precondition for correctly displaying the primary and percentage values is complete and correct entry of the
nominal values for the transformers and the protected equipment as well as current transformer ratios in the
ground path when configuring the device. The following table shows the formulas which are the basis for the
conversion from secondary values into primary values and percentages.
2.17.3.1 Display of Measured Values
Table 2-16 Conversion formulae between secondary values and primary/percentage values
Table 2-17 Legend for the conversion formulae
Measured Values Second-
ary
Primary %
I
A
, I
B
, I
C
,
I
1
, I
2
I
sec
I
N
= 3 ·I
0
(calculated)
I
N sec
I
N
= measured value
of I
N
input
I
N sec
I
Ns
I
Ns sec.
Parameters Address Parameter Address
CT PRIMARY 204 Ignd-CT PRIM 217
CT SECONDARY 205 Ignd-CT SEC 218
FullScaleCurr. 1102