Megger offers a full range of solutions for Very Low Frequency (VLF) and tan delta insulation testing, and Partial Discharge (PD) detection and mapping.
VLF or 0.1 Hz testing is used on cables as an alternative to DC testing. It is designed to test cables for weak spots in insulation due to electrical trees. Our Cosine Rectangular VLF systems have been developed to test very long cables and meet international standards such as IEEE 400 and IEC HD 620/621. Our PD systems utilizes the Damped AC (DAC) method for truly non-destructive PD diagnosis.
Tan delta diagnostics is a great way to diagnose the integrity of the cable’s insulation and health so you can take measures to avoid preventable in-service cable failures. Powered by a VLF unit, Tan Delta diagnostics can be used to detect water trees, one of the leading health conditions of MV extruded type cables, and insulation degradation and aging.