High-Voltage Tan and Cable Testing with Tan Delta Technology

The TD-34E Tan Delta analyses voltages and current waveforms, and calculates tan delta numbers. A wirelessly connected laptop computer can be used to display and store the results.

A voltage source is needed to energise the cable when testing and what is typically used is a Very Low Frequency (VLF) AC Hipot. The VLF-34E is a 34kV (peak) unit that is capable of testing from 0.5μƒ of cable load at 0.1 Hz, to 5.0 μƒ at 0.01 Hz.

VLF hipots are also widely used for testing newly installed and/or repaired cable before reenergising to insure the cable is sound and for testing critical cable runs.

To test a cable with a power of 60Hz requires a very large high-voltage supply, while it is not practical to test a cable of several thousand feet with this power supply. At a typical VLF frequency of 0.1Hz, it takes 600 times less power to test the same cable compared to 60Hz. The magnitude of the tan delta numbers increase as the frequency decreases, making measurement easier.

Please download this white paper to find out more.