: Fluid Testing Packages for Electrical Asset Management

How does Oxidation Inhibitor help my transformer?

Acids are formed in transformer fluids by the reaction of oxygen with fluid itself. The amount of oxygen present, moisture, and thermal conditions all contribute to the rate of acid production in transformer fluids.

The oxidative processes are many but involve creating “free radicals” in the oil which lead to the acid production. Oxidation Inhibitors are a group of phenolic compounds that slow this process by interrupting the “free radical” reaction with the fluids.

New oils contain amounts of natural oxidation inhibitor compounds, but these are lessened by the refining process and natural oxidative reactions. Reclamation of oils also remove the natural inhibitors present.

The addition of synthetic oxidation inhibitors to transformer fluids can be used to interfere with the oxidative process and extend the life and capability of the fluid.

The most common Oxidative Inhibitors added to mineral oil are:

2,6-ditertiary-butylphenol (DBP) and 2,6-di-tertiary-butyl-4-methylphenol or 2,6-di-tertiary-butyl-paracresol(DBPC).

DBP and DBPC oxidation inhibitors for helping transformer oil

Other proprietary compounds are used that are fluid specific such as Natural and Synthetic Esters fluids, but still maintain the same purpose to interrupt the oxidation process.

Once the Oxidation Inhibitors are exhausted in the fluids, oxidation processes will start to accelerate, and the acid formation and all the detrimental effects will begin to increase.