With Megger’s new test van, it is now possible to carry out a full range of tests on power transformers quickly and conveniently at any location that can be reached by road. This means that transformer condition can be readily assessed as an aid to preventing future failure and that faults that have already occurred can be located rapidly, ensuring the fastest possible return to service of these costly and often critical assets.
Designed to reduce testing time and to maximize user safety, the Megger transformer test van can positively and accurately identify deterioration of electrical insulation by performing tests that include insulation resistance testing, dielectric frequency response analysis, dissipation factor and capacitance measurement.
Frequency response analysis provides a dependable way of detecting mechanical damage caused by poor handling during transportation of by exposure to high-level faults. This facility is invaluable, as such damage cannot otherwise be found without dismantling the transformer for a visual inspection of its internal structure.
In addition, the equipment in the van can check ratio, vector group, no-load and short-circuit loss after repairs to guarantee the quality of maintenance. Oil samples can be subjected to breakdown tests and gas analysis. A further key feature of the equipment provided in the van is automated switching and configuration of test circuits, which ensures the highest possible level of safety.
The van has two sets of cables, HV and LV, which are shared among the different instruments – most instruments on-board share a common connection to the test object. Test circuit configuration and switching are performed automatically, an arrangement which makes errors virtually impossible and ensures the highest possible level of safety.
All instruments are accommodated within a 19-inch rack that also contains power supplies and safety indication. The van’s central control unit uses Megger’s acclaimed PowerDB software to control the tests and to provide a comprehensive record of test data. This data can then easily be accessed for reporting or for analysis to provide, for example, a comparison between current and historical test results.
“The transformer test van was developed to meet the needs of companies requiring a safe, reliable and readily available way of testing power transformers on site,” said Damon Mount, sales manager for Power Products at Megger. “It’s a mobile, all-in-one testing solution that can quickly offer engineers and managers peace of mind about the condition of some of their most important assets.”