Cable Oil as Special Sort of Oil Insulation

Power cables with Insulation Oil

Insulation Oil filled HV cables

Special Sort of Oil Insulation

The cable oil is used to impregnate the paper insulation of cables and to fill the cables for operating voltages up to 35 kV. Important is that cable oil should have good dielectric properties – low dielectric loss tangent, a high resistance to the electric field of ionized gas (gas-resistance) and electrical properties stability during prolonged heating. GlobeCores’s technology is real benefit for reclamation of special sorts of insulation oil!
Using of Liquids Dielectric
The liquid dielectrics are widely used in electrical equipment. The base sorts of insulation oil are:
– transformer oil
– cable oil
– condenser oil.
The liquid dielectrics fill the inner space of power transformers, reactors, circuit breakers, capacitors, cables and other electrical devices. This oil saturate porous winding insulation well, cardboard and other porous insulating materials. In oil circuit breakers dielectric fluid not only insulates the conductive parts, but also acts as a medium, which quench the electric arc that occurs due to contacts of circuit breakers.

Sorts of Cable Oils
For power cables depending on the voltage, design and application, the following sorts of cable oils and compounds are used.

Cable Oil KM-22
KM-22 oil cable oil is the impregnating and insulating medium in the oil-filled cables. The oil has good dielectric properties – low dielectric loss tangent, a high resistance to the electric field of ionized gas (gas tight), stable electrical properties during prolonged heating. The oil KM-22 is produced by selective solvent purification. This oil doesn’t contain additives. Oil is intended for impregnating masses of voltage power cables 1-35 kV with paper insulation.

KM-22 Properties
1.Kinematic viscosity at 100 °С, mm² / sec, not less than: 22,0
2.Acid number, mg КОН / g, not more than: 0,03
3. Temperature, °С: – open cup flash point, not lower than 2700
– pour point, not higher than -10
4. Mechanical impurities: None
– ash: 0,007
– water: еraces
5. Insulating strength at (25 ± 10) °С, AC and frequency 50 Hz, MV / m, not less than: 15

Cable oil C-220
To impregnate the height voltage cables of high-pressure in steel pipes, cable oil of medium viscosity (P-100 and P-220) are used. Cable oil C-220 is made from air oil which has a low freezing point and their purification by dewaxing. It is used for impregnating oil-filled cables of high pressure, in contrast to the transformer oil, this oil does not contain aromatic hydrocarbons, which provides better electrical characteristics
Viscous Cable Oil P-28
For cables with voltages up to 35 kV one can use the compound of a viscous oil P-28 (bright stock) and rosin. Viscous cable oil P-28 (bright stock) is made of the viscous oil concentrate from Surakhan selective crude oil by acid cleaning. Technology of this oil production has its own peculiarities. Due to the fact that the oil is highly viscous (about 250 cSt at 50 ° C), it can’t be exposed to an alkaline cleaning. Therefore, immediately after acid cleaning and sediment of acid sludge, acid oil contacts with gumbrinom at high temperature.
Oil MH-2
Low viscosity oil MN-2 is for oil-filled cables for low and medium pressure (1-3 am).
Conclusion. As we see, the cable oil has its own characteristics and better properties than other sorts of insulation oil: it can be very viscous with good dielectric properties. Therefore the requirements for oil reclamation equipment increase. GlobeCore’s offer comprehensive custom solution for reclamation of cable oil.

обновлено: August 29, 2017 автором: Helen Galchenko