Winding resistance test of inductive test objects, such as power transformers, is one of the most effective non-intrusive ways of checking its condition. Due to their advanced design, DV Power winding resistance meters provide high test currents (up to 100 A DC) and high accuracy (up to 0.1%) within light and portable test instruments. In addition to winding resistance measurement, it is also possible to perform simple, quick and reliable transformer on-load tap changer condition assessment by recording the test current during tap changer operation, also known as DVtest. Because of that, problems with a tap changer connection, contacts, and switching procedure can be detected.

DV Power winding ohmmeters consist of single-phase RMO-T and three-phase TWA series. Models from the TWA series are designed for six-winding resistance measurement of power and distribution transformers, with only one single-step cable setup. As a result of reducing the total test time, it enables significant saving of time and money.

Typical application areas of these instruments are high-voltage substations and industrial environments. They are intended to measure the resistance of:

• Transformer windings
• On-load tap changers
• Generators
• Electrical motors
• High-current bus bar joints
• Cable splices
• Welding joints