Transformer maintenance and oil analysis

Transformer maintenance and oil analysis

Why is a periodic transformer maintenance and oil analysis so important?

The maintenance of transformers plays a very important role for the operation of an electrical substation. As electrical devices that normalize the voltage of an alternating current allowing the power to be maintained at stable levels, it is necessary to perform the relevant maintenance to increase their useful life.

It is important to carry out an oil analysis and maintenance of transformers since the performance of substations, generation plants, urban areas or thermoelectric plants depends on it. Pollution, humidity or even heat, may be some of the factors that trigger a series of failures in their operation.

With the aim of increasing the useful life of transformers, at Enel X we carry out an oil analysis that will help reduce the risks of failure, as well as improve the reliability of their operation.

What are the benefits of performing this service?

With our transformer maintenance and oil analysis service:

1. You will minimize the electrical risks for your personnel.

2. You will prevent temperatures beyond normal.

3. You will avoid strange sounds or hums.

Do you know how our service works?

We offer different types of oil analysis:

1. Dielectric analysis:

Benefits: Knowledge of the state of the paper-oil insulation system of the transformer to maintain the operation in reliable conditions, or to plan the preventive or corrective maintenance required according to the result obtained from the diagnosis.

Description: Set of tests to determine the chemical quality of the oil, the water percentage and the degree of impregnation of oxidation products in the insulating paper.

• Scope: 

A sample of oil is taken and the following tests are carried out:

  • Dielectric stiffness norm astm d- 877: 07
  • Moisture content norm astm d-1533: 00 (05)
  • Neutralization number norm astm d- 974: 08
  • Specific Gravity norm astm d-1298: 99 (05)
  • Interfacial voltage norm astm d- 971: 99a (04)
  • Standard color astm d-1500: 07

• Applications: Power or distribution transformers immersed in insulating mineral oil located on the floor.

2. Chromatographic analysis:

  • Benefits: Identify possible electrical or thermal faults inside the transformer to avoid an unexpected output.
  • Description: Set of tests to detect the presence of combustible gases such as hydrogen, carbon monoxide, methane, ethylene, acetylene, and others such as carbon dioxide. Then, based on the concentration of each of them and some relationships in the composition, incipient or advanced failures are diagnosed, such as internal discharges, crown effects, and overheating of oil or cellulose.
  • Scope: Oil sample taken for analysis in chromatograph and presentation of results indicating the diagnosis in case there is a high concentration of one or several components.
  • Applications: Power or distribution transformers immersed in insulating mineral oil located on the floor.

3. PCB Analysis:

  • Benefits: Allows taking the necessary actions to protect the environment and people from the effects caused by improper handling.
  • Description: Analytical colorimetric screening test used to determine the presence of chloride ions, and therefore the possible presence of PCB, in dielectric oil.

According to the environmental commitment signed by Colombia in the Stockholm Convention, the owners of the equipment must deliver the PCB inventory before 2024.

  • Scope: Taking a sample of 100 ml dielectric oil for quantitative analysis of Polychlorinated Biphenyls by gas chromatography according to ASTM D4059-00 (2010).
  • Applications: Power, distribution transformers and/or equipment immersed in insulating mineral oil, located on the floor.

4. Analysis of furan content

  • Benefits: Identify the remaining useful life of the transformer and therefore the productive time in safe conditions.
  • Description: Set of tests to assess the concentration of the furfulaldehyde derivatives that result from the thermal degradation of the cellulose incorporated in the solid insulations of the transformer.
  • Scope: By analyzing an oil sample, the content of furanic compounds can be determined, the presence of which shows a thermal wear of the paper.
  • Applications: Power or distribution transformers immersed in mineral insulating oil, with more than 12 years of operation and located on the floor.

What are the advantages of carrying out the oil maintenance and analysis of your transformers with us?


Over 20 years offering energy solutions and accompanying Colombian companies in their growth and electrical infrastructure projects.


First Public Services Company in Latin America certified in Oshas 1800, which supports the development of projects with qualified personnel and high occupational safety standards.


Guarantees for your works and projects: quality, reliability, RETIE and RETILAP certification.

Reduce electrical risks in the operation of your instllations and ensure the proper functioning of your equipment, schedule your personalized consultation here or contact us at 6016000 option 1 in Bogota or at 01 8000 935946 countrywide.

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