Electrical Insulating Liquids are used as insulation and coolant intermediates in electrical distribution and power devices such as transformers, regulators, reactors, rockets, starters and other related devices.

This paper intends to define and point out the physical, electrical and chemical parameters of importance of electrical insulating oil.

Physical Properties

Electrical Properties:

1- 60Hz dielectric degradation voltage: The dielectric degradation voltage of mineral insulated oil indicates the ability of the oil to withstand intermittent electrical degradation in electrical devices.

1.1.1 Electrical degradation-plate electrodes – This test, in which the plate electrodes are used, is suitable for the evaluation of the quality of mineral insulation oils sent by tanker trucks, wagons and barrels. This method is not suitable because of the low sensitivity for measuring oil which should have a minimum acceptable level of degradation resistance for use in some devices.

1.2-1 Dielectric Destruction – VDE Electrodes – Due to their high sensitivity to contaminants, they are used in freshly manufactured oils that have the least acceptable amount of degradation resistance for use in some devices. To reach the required level, the oil must be smooth and hydrogenated and degassed (as a guideline for the user of this test, it is said that the product should be an acceptable method that is inherently free of contaminants and containing the moisture and gas available 15PP and 0.5% respectively.) This test method is not applicable to fresh oil that has not been upgraded.

2- Dielectric degradation voltage: Immediate excitation: Immediate excitation resistance in electrical devices is a critical issue. The instantaneous excitation voltage degradation of an oil demonstrates the ability to withstand the electrical degradation of that oil at transient voltage pressures (when switching on and off the electrical currents).

Coefficient of dissipation: The coefficient of dissipation is a measure of the dielectric loss in an oil. Low dissipation coefficient indicates low dielectric loss and low dissolution of pollutants

chemical properties :

Neutralization Number: Low acid content of the whole mineral insulation oil is essential to minimize electrical conductivity and corrosion of metals and to maximize the life of the insulation system.

Neutralization Number: Low acid content of the mineral mineral insulation oil to minimize electrical conductivity and corrosion of metals and to maximize the life of the essential insulation system. Inside or outside the oil, under laboratory conditions, and aromatase reflects an oil but does not measure it. The background of most oil-filled transformers is filled with nitrogen or oxygen-free air. No slight relationship was found between the tendency to produce oil gas, which results from the D2300 method, and the improvement in oil life during consumption.

PCB Value: International law specifies guidelines that apply to electrical insulation devices and oils containing PCBs, the agenda applies to special machines or parts of insulated oils whose PCB value is specified. New insulated oils that meet these specifications should not have PCB detectable values. The PCB indeterminate protection specified by Method D4059 is a document that allows the oil and device containing it without labeling and without the necessary restrictions for Use PCB-based materials

4- Corrosive sulfur: The absence of elemental sulfur and unstable thermal compounds that produce sulfur is essential to prevent the corrosion of special metals such as copper, silver and lead that are in contact with the insulating oil.

Water content: Low water content in mineral insulation oil is essential for achieving ideal electrical resistance and low electrical loss and for maximizing the life of the insulation system and minimizing metal corrosion.

Oxidation Resistance: Oil sludge and acidity caused by oil oxidation during storage, production and consumption should be kept to a minimum. This minimizes electrical conductivity and maximizes the life of the electrical system and the resistance to electrical degradation. It also ensures that heat transfer is satisfactory.