Omicron CT SB2 User Manual page 160

CT Analyzer User Manual
Proceed as follows to perform a VT ratio measurement:
1. Connect the OUTPUT sockets and input SEC of CT Analyzer to the primary side of the VT, and
CT Analyzer input PRIM to the secondary winding of the VT (see Figure 10-12).
Figure 10-12: Wiring example for VT ratio measurement
WARNING
Death or severe injury caused by high voltage or current possible
Connecting the CT Analyzer output to the secondary side of the VT by mistake will
cause hazardous voltages on the primary side.
► Make sure to connect the CT Analyzer output to the primary side of the VT.
2. Open the Quick Test measurement function of CT Analyzer or start the CT Analyzer Quick Test tool
of the CT Analyzer Suite software.
3. Select the VT Ratio measurement type. Set the amplitude to the maximum output voltage of 40V
and the frequency to the mains frequency. Refer to Figure 10-13.
Note: If it is necessary to suppress mains frequency interferences, use the Advanced measurement
type with a frequency of e.g. 3Hz above the mains frequency (e.g. 53Hz) and choose the frequency-
selective measurement mode with a filter bandwidth of 6Hz. Mains frequency interferences are then
suppressed by 120 dB.
Measurement settings
Figure 10-13: CT-Quick test card with settings for VT ratio measurement
4. Start the measurement by pressing the
VT Ratio tab of the CT Analyzer Quick Test software tool. The measured values are displayed and
permanently updated as long as the measurement is active. Refer to Figure 10-14.
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key on CT Analyzer or clicking the ON button on the
OMICRON