One of the smallest and most rugged instrument of its type, Megger’s award winning new FRAX 150 sweep frequency response analyser (SFRA) is a powerful tool for revealing potential electrical and mechanical problems in power transformers, many of which are difficult or impossible to detect using other methods. The instrument is completely self-contained, with an integral PC that has a high-resolution colour screen featuring a powerful backlight that makes it easy to read even in direct sunlight.

Meeting all international standards for SFRA measurements, this innovative instrument offers a larger dynamic range and better accuracy than any other comparable test set currently available. In addition, for the test connections to the transformer, it makes use of special cabling technology that ensures repeatability of results.

The FRAX 150 operates by applying a sweep frequency test signal to the transformer and monitoring its response. The result is a unique fingerprint which, when compared with a reference fingerprint for the same transformer, reveals a wide range of faults. These include winding deformations and displacements, shorted and open windings, loose and broken clamping structures, core connection problems, core movement and hoop buckling.

Megger’s FRAX 150 incorporates powerful analysis and decision support software. In addition to offering the traditional magnitude versus frequency/phase display, this software also allows users to present data in an impedance or admittance versus frequency view, which is a powerful analytical tool for many types of transformer.

The test frequency range covered by the FRAX 150 is 0.1 Hz to 25 MHz, and users can set the range employed for individual tests to match the needs of the application. By default, the number of test points used for each frequency sweep is 1,046, but users can choose to extend this up to a maximum of 32,000. Typical measurement time is 64 seconds, but a fast mode is available that is capable of delivering results in just 37 seconds.

Also available from Megger is the economical FRAX 101 sweep frequency response analyser, which offers functionality similar to that of the FRAX 150 but is designed for use with an external laptop computer. To facilitate interchange of data with the PC, the FRAX 101 additionally supports Bluetooth wireless technology. 

Small and easy to carry, with an operating temperature range of -20ºC to +50ºC, the Megger FRAX 150 and FRAX 101 sweep frequency response analysers are ideal for use in the field. They are supplied complete with ground cable, four 3 m braid sets, two C clamps, an 18 m generator cable, an 18 m test cable, user manual and Windows software.

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