The difference between transformer oil and alternative oil

Today, cutting-edge companies like Petronas and Millers produce high-quality transformer oil with excellent performance properties. Sometimes referred to as “insulating oil”, this fluid is designed specifically to serve as electrical insulation and as a transformer coolant.

While this mineral oil-based solution offers many benefits, it does present potential drawbacks. As a result, lubricant manufacturers are developing alternative oils to address concerns.

Here, we look at the two different products in detail – including their key roles, characteristics, pros and cons.

Transformer oil

The main function of a transformer oil is to insulate and cool transformers and supress arcs. To perform its role effectively, the built-for-purpose insulating oil is specially formulated with coveted properties. These include good thermal stability and exceptional dielectric strength, giving them the capacity to cope with electrical stress. With a mineral oil base, an added advantage of transformer oil is its affordability.

Transformer oil is not without its disadvantages, however. These include being flammable and environmentally unfriendly. If spills or leaks occur, oils are a potentially harmful pollutant, and can also cause sludge to accumulate within transformers, impacting their performance.

Alternative oil

As the name suggests, alternative oil is designed as another option for transformer oil applications and serves the same function. There are three main types of alternative oil with different properties: silicone fluids, natural esters (vegetable oils) and synthetic ester.

Natural and synthetic esters offer improved fire safety and biodegradability. Silicone fluids hold up well under electrical stress and have a high fire point, but are not as eco-friendly as their ester-based counterparts.

As well as being more biodegradable and less flammable compared to transformer oil, alternative oil can also offer a longer service life. It’s worth noting that alternative oil does have disadvantages. It is more expensive than traditional transformer oil, and some varieties feature different compatibility and viscosity characteristics.

If your operation requires best-in-class transformer oils from leading lubricant brands, you can count on our selection. Browse our transformer oil options now or get in touch for further product information regarding a specific application.