Test Laboratory for Transformer Materials
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Test Laboratory for Transformer Materials
Test laboratory for transformer materials
Do you know the chemical age of your transformer? Well we do!
There are numerous complementary methods for diagnosing the transformer ageing process early and reliably. The Siemens Test Laboratory for Transformer Materials is completely focused on the laboratory diagnostics of oil-filled electrical equipment. The highly qualified personnel are constantly developing new methods for ageing diagnostics and are using this knowledge for the benefit of our customers.
Accredited as an independent test laboratory in accordance with ISO 17025 (Certificate)
Our services include insulating oil and material testing. The diagnostic test procedures vary between ageing analysis or condition detection of oils /insulating materials and the new state assessments of oils /insulating materials.
The lifespan of a transformer largely depends on the ageing of the solid and liquid organic insulating materials. In normal operating conditions, below the maximum permissible load, and with regular maintenance and care, a transformer's lifespan can be extended to well over 30 years.
Nevertheless, during the working life of a transformer abnormal events could occur, for example transient over voltages, overheating during emergency operation, dynamic stress and faults in the cooling. These processes result in an accelerated ageing of the transformer materials.
Whether it is a case of new construction, operation, retrofit or repair, it is always a matter of reliably recognizing material degradation and rectifying it. For this purpose an extensive knowledge of the materials as well as a specific, precise analysis is fundamental. In order to avoid costly breakdowns, minimize downtimes and extend the lifespan of a transformer, the performance of a regular trend analysis and targeted maintenance are indispensable.
The combination of moisture in the oil and in the cellulose is an indicator of ageing. The most important method for the diagnosis of the ageing process as a result of dielectric, thermal, dynamic and chemical ageing in oil and oil-paper insulation is the Dissolved Gas Analysis (DGA). The Siemens Test Laboratory for Transformer Materials offers a comprehensive service, from the collection of samples to analysis and assessment.
The sampling device, developed in collaboration with the customers, offers the following advantages:
During the mostly decades-long service life of a transformer, materials too are subjected to considerable ageing processes. Through our tests we are able to determine the condition of the materials, and offer our clients the possibility to plan any necessary maintenance measures early.
Analyses of solid insulating materials, conductive metallic materials (grain-oriented electrical steel and copper materials) as well as coating materials and sealing materials, are carried out.
Inhibitors are age protecting agents which delay the decomposition of the insulating oil. The IEC 60296 accredited inhibitor DBPC (Di-tertiary-butyl-para-cresol), with a weight percentage of 0.25 ± 0.040 , is used. Inhibited oils are preferred for transformers > 200 MVA, for heavily loaded transformers such as traction transformers, for oven transformers or at special customer request. When the accelerated oil ageing process is caused by a transformer malfunction, the original inhibitor content (0,3), can be restored by adding a calculated amount of DBPC in powder form, once the failure has been fixed. Even in the case of normal DBPC- deterioration, the oil can be re-inhibited, although an oil change would be less expensive. This decision can be made only based on the results of the other oil value tests: if these are normal then a re-inhibition can be successful. The inhibitor content is determined using infrared spectrometry or gas chromatography with MS-detector.
Material Testing Laboratory - Analysis for Transformers
Electrical Research and Testing Laboratory Nuremberg
Accreditation Certification - Annex
Chemical physics laboratory
Katzwanger Str. 150
90461 Nürnberg, Germany
+49 (0) 911 - 434 -2324