Condition monitoring of any transformer is critical to having a dependable and uninterrupted power supply. Key to ensuring optimised performance of these expensive assets is the condition of the insulation system and in particular with the insulating oil. Information from analysis data is of great importance in transformer oil management. Similar to a person's blood count, regular insulating oil analyses provide detailed data. These can be used to determine measures for an improved service life and increased reliability of transformers. Moreover, they are the basis for digital data management and therefore a daily standard at Electrical Oil Services.
In order to obtain the most accurate overview of the condition of your transformer oil, it is important to regularly collect analysis data. These are obtained by taking samples of the insulating oil which are then analysed in the laboratory. Various parameters, such as colour, purity, breakdown voltage, water content, acidity and the loss factor of the transformer oil’s permittivity, are analysed. Furfural analyses are also carried out. These analyses provide insights into the thermal degradation of the solid insulation and, consequently, into the condition of the solid dielectric material, such as paper or compressed chipboard. These tests must be carried out in accordance with standard IEC 60422.
The collected data provide information about the current condition of the insulating oil and thus also about the condition of the transformer.
Analytical data becomes particularly meaningful when viewed over a longer period of time. Only through the continuous recording and comparison of historical values can changes in the condition of the transformer oil be reliably identified. Trend analyses help to identify gradual ageing processes at an early stage and to schedule maintenance measures in a targeted manner.
This enables transformer operators not only to respond more quickly to critical developments, but also to implement condition-based maintenance strategies. This reduces unnecessary maintenance intervals, increases operational reliability and supports the cost-effective use of the equipment throughout its entire lifecycle.
The evaluation of the insulating oil analysis data is crucial for assessing the overall condition of a transformer. By analysing the condition, potential problems within the transformer oil are detected at an early stage and appropriate measures can thus be taken in good time.
With EOS® analysis data
In addition to assessing the condition of transformers, analysis data also plays an important role in terms of data management. In many companies, disconnected data sytems are still one of the biggest challenges. That's where we come in with our EOS database solution. It provides you with all the information in the format you require, such as Excel, PDF or online database and many more.
After all, it is only through the regular collection and assessment of data that digital data management can be developed. All relevant information on your transformers can be stored in the EOS database centrally and accessed at any time. This not only increases efficiency, but also enables optimal maintenance control.
Electrical Oil Services offers the EOS® database based on the Salesforce infrastructure. Here, information from transformer oil analyses is stored in a data-protected environment. For example, data from gas-in-oil analyses (DGA analyses), which provide information on the thermal and electrical condition of transformers. In addition, the history of the load on individual transformers is also recorded.
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The use of insulating oil analysis data is an important part of assessing the overall condition of transformers. Problems can be detected at an early stage and appropriate measures can be taken. In addition, the regular collection and evaluation of data enables efficient data management. At Electrical Oil Services, you benefit from a professional evaluation of your analysis data which enables you to ensure that your transformers are always in optimal condition and enjoy a long service life.
FAQ – Frequently asked questions about transformer oil analysisWhy are regular transformer oil analyses important?Regular analyses help to assess the condition of the insulating oil – and therefore of the entire transformer – at an early stage. Potential damage or ageing processes can be identified in good time, allowing appropriate measures to be taken. Which parameters are examined during an insulating oil analysis?Typical analysis parameters include colour, purity, breakdown voltage, water content, acidity and the loss factor of the transformer oil’s permittivity. What is the advantage of a trend analysis of analytical data?By examining measurement values over the long-term, changes and ageing processes can be detected at an early stage. This enables condition-based maintenance and reduces the risk of unplanned outages. What role does IEC 60422 play in transformer oil analyses?The IEC 60422 standard defines recommendations for the monitoring and evaluation of insulating oils in electrical equipment. It serves as an important basis for carrying out and interpreting oil analyses. How does the Electrical Oil Services (EOS ®) database support transformer management?The Electrical Oil Services (EOS ®) database enables centralised and data-secure management of all relevant analysis data. This allows maintenance measures to be planned efficiently, trends to be tracked and informed decisions to be made. |
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This blog was first published on November 2, 2023 and updated on July 28, 2026.