Technical library

Brochure for the Baker AWA-IV

Brochure for the Baker PPX

Electrical insulation degrades over a period of time because of various stresses which are imposed upon it during its normal working life. The insulation has been designed to withstand these stresses for a period of years, which would be regarded as the working life of that insulation. This often runs into decades.

Pinpointing concealed problems inside a resistive-type OLTC before physical inspection - the application of true DRM.A maintenance team at the Electric Power Transmission Network in the City of Karbala performed routine electrical tests on a transformer including: winding resistance measurements (WRM), transformer turns ratio (TTR), short circuit impedance (SCI), excitation current, and line-frequency power factor (a.k.a. dissipation factor or tan delta). This case study looks into their investigations and their results.  

Software download files for FREJA

testing accessories

The subject 69 kV bushings are installed on a 10 MVA, 69/13.09 kV Dyn1 two-winding transformer. After completing on-load tap changer (OLTC) maintenance on this 1969-vintage transformer, the utility owner followed with electrical tests.

A 21st century trend in electrical instrumentation has leaned toward smaller, lighter and easier to manipulate testers through microcircuitry. Being portable and easy to manipulate can be beneficial enough, but there’s much more to it. Size reduction is not just for ease of manufacturing or an advertising gimmick. Multiple instruments can be combined into a single handheld tester, so that an entire job can be completed with a single piece of test equipment. The user can benefit from notable cost savings and job improvement. This article will examine how many of the functions found in multiple different instruments can be included in just one handheld tester.

The Megger IDAX322 is operated by an easy-to-use software with assessment guidance informed by international standards and over 25 years of field experience with DFR technology.

Electrical maintenance departments are often faced with the challenge of performing different tests on instrument transformers according to official standards and within a limited shutdown time. This is made even more difficult when multiple instruments are needed to perform all the required tests.