VLF Tan Delta – Tan δ – Dissipation Factor – Loss Angle

The TD-E Series, designed and produced by HVI, are solid state transducers designed to mate with HVI VLF-E Series products to measure the TD, or Dissipation Factor, of a cable or other load under elevated 0.1 Hz. high voltage conditions. The TD-E Series measures and wirelessly reports the shift in the phase between the voltage and current of a cable or other load to determine the level of insulation degradation. The primary application is for testing solid dielectric cable insulation for water trees and other defects or contamination. TD testing is relatively easy to perform and interpret the health of the insulation tested. It is like power factor testing coils or other insulation, except performed at 0.1 Hz for testing very high capacitance loads.

Pictured here is the TD-65E from HVI. It is designed to measure up to 65 kVac peak VLF voltage and current. It can be used (up to 65 kVac peak voltage) with any model of the VLF-E Series from HVI under the operation and control of the E-Link Software designed for HVI produced VLF and Tan Delta products.

Below is a photo of a VLF 200 kVac mobile testing truck equipped with a motor generator, a 0-200 kVac @ 0.1 Hz. model VLF-200CMF, and 0-200 kVac Partial Discharge and Tan Delta diagnostic measurement Instruments. HVI has offered its 200 kV VLF model since 2004.