VLF frequency extention: 0.05 Hz and 0.02 Hz

Extension for the S-24 VLF / S-36 VLF / S-44 VLF / S-57 VLF tester to enable measurements with voltages of a frequency of 0.05 Hz and 0.02 Hz. The extension allows testing of cables with a longer length and higher total capacitance than allowed by the standard frequency of 0.1 Hz.

For example, for a test voltage of 44 kV_RMS and a unit capacitance of the cable of 0.25 µF/km:

• the standard frequency of 0.1 Hz allows for testing a cable with a length of approx. 6.4 km and a capacitance of 1.6 µF,
• the non-standard frequency of 0.02 Hz allows for testing a cable with a length of approx. 25 km and a capacitance of 6.3 µF.

 

Frequency	Number of full waveforms per minute	Number of full waveforms per hour
0.1 Hz	6	360
0.05 Hz	3	180
0.02 Hz	1.2	72