A Pragma Group Company

Sweep Frequency Response Analyser (SFRA)


The Megger Frax 101


The Megger Frax 150


Power transformers are some of the most vital components in today’s transmission and distribution infrastructure. Transformer failures cost enormous amounts of money in prolonged outages and unscheduled maintenance. It is important to avoid these failures and make testing and diagnostics reliable and efficient. SFRA with instruments such as the Megger FRAX is an off-line low voltage test that is recognised to meet these requirements.

Using Sweep Frequency Response Analysis (SFRA) on power transformers permits the detection and diagnosis of internal mechanical and electrical problems that other methods are unable to detect. Defects such as:
• Winding deformations and displacements
• Shorted turns and open windings
• Loosened clamping structures
• Broken clamping structures
• Core connection problems
• Partial winding collapse
• Faulty core grounds
• Core movements
• Hoop buckling

Knowing the internal health of your transformer allows you to operate at maximum load without compromising reliability.

In the SFRA test a range of frequencies at low voltage is injected into each of the windings and the response measured at the other windings, yielding a reference signature which provides valuable information about the transformer throughout its lifetime.

The range of FRAX Sweep Frequency Response Analysers from Megger meets the most demanding requirements. From the smallest and most accurate SFRA unit on the market to its outstanding dynamic range and flexibility. This combined with dimensions, weight and accessories equalled by no other brand.