The FRAX99, FRAX101, and FRAX150 sweep frequency response analysers (SFRA) are the smallest and most rugged instruments of their type and powerful tools for revealing potential electrical and mechanical problems in power transformers, many of which are difficult or impossible to detect using other methods.
Meeting all international standards for SFRA measurements, these innovative instruments offer a larger dynamic range and better accuracy than any other comparable test sets currently available. In addition, for the test connections to the transformer, they use a special cabling technology that ensures the repeatability of results.
The FRAX series operates by applying a sweep frequency test signal to the transformer and monitoring its response. The result is a unique fingerprint that reveals a wide range of faults when compared with a reference fingerprint for the same transformer. 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 series incorporates powerful analysis and support software. In addition to offering the traditional magnitude versus frequency/phase display, this software allows you to present data in an impedance or admittance versus frequency view, a powerful analytical tool for many transformer types.
The test frequency range covered by the FRAX is 0.1 Hz to 25 MHz, and you can set the range employed for individual tests to match the application’s needs. By default, the number of test points used for each frequency sweep is 1046, but you can extend this up to a maximum of 32 000. The typical measurement time is 64 seconds, but a fast mode is available that can deliver results in just 37 seconds.
Small and easy to carry, with an operating temperature range of -20 ºC to +50 ºC, the FRAX sweep frequency response analysers are ideal for use in the field. They are supplied with ground cable, four 3 m braid sets, two C clamps, 9 m or 18 m connection cables, a user guide, and Windows software.
There are three models in the FRAX series:
- FRAX099: optional battery, connects to an external laptop for control and data analysis with standard USB cable
- FRAX101: optional battery, supports both Bluetooth and standard USB connection for control by and exchanging data with an external laptop, includes built-in ground loop detector
- FRAX150: mains-operated with an integrated PC that has a high-resolution colour screen featuring a powerful backlight that makes it easy to read even in direct sunlight and includes a built-in ground loop detector