Ct Ratio Measurement - Omicron CT SB2 User Manual

10.6

CT ratio measurement

CT ratio measurement is a predefined measurement type, intended especially for
the quick measurement of CT ratios.
Note: This is not a complete CT test. It only determines the current ratio of CTs.
To select the CT Ratio measurement type, use the
cursor to the Measurement Type field in the CT-Quick card and then press the
CT Ratio soft key.
Figure 10-9: CT-Quick card and Results card for CT ratio measurement
For the CT Ratio measurement type, the CT-Quick card holds the following measurement quantities:
Table 10-7: Parameters for CT Ratio measurement type
Parameter Description
Output The output signal type is fixed to "AC".
U/I Operating mode of the internal signal generator: voltage or current source. Fixed to
"Voltage".
Amplitude RMS voltage of the output signal. Adjustable by the user.
Possible values: 0 to 40V.
Default: 1.00V.
f Frequency of the output signal. Adjustable by the user.
Possible values: 5.0 to 400.0Hz or soft keys 16.7Hz, 50Hz, 60Hz or 400Hz.
Default: 50Hz
Load Fixed to "On".
Setting the Load parameter to "on" and specifying the winding resistance and the
unsaturated inductance in the fields R and L will prevent saturation of the connected
CT.
The output generator of CT Analyzer then keeps the DC part of the output current at
zero using a current regulator.
R, L Winding resistance (R) and unsaturated inductance (L) of the CT, used by the internal
output regulator to prevent saturation of the connected CT (see Load above).
Possible values: 0 to 1000
Default: 1.00
If these values are not set correctly for the connected CT, the CT will saturate sooner or
later, depending on the inaccuracy of the values used.
OMICRON
Ω
or 0 to 1000H.
Ω
for R and 50.00H for L
Using the Quick Test feature
cursor key to move the
How to get there:
Press the Main soft key in
any test card
Main Menu:
- New Quick-Test
OK soft key
CT-Quick card:
Measurement Type:
CT Ratio
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