Tag Archives: transformer oil

Oil Reclaiming and Oil Degassing Unit CMM-0.6 Launched in Italy

October 8, 2016Newsoil degassing, oil reclaiming, oil reclamation, transformer oil

October 2016: GlobeCore technical support team commissions an oil reclaiming and oil degassing unit CMM-0.6 in Italy.

The oil reclaiming equipment will be operated in Carpenedolo, Brescia. The CMM-0.6 is a portable oil station that purifies electrical insulating oils, removing mechanical impurities, water and gas. It guarantees the desired oils parameters for oils with viscosity less than 70 cSt (at 50°C).

The equipment is in demand among facilities dealing with installation, repair and operation of oil-filled high-voltage equipment (high-voltage switches, power transformers, etc.).

Depending on the type of oil reclaimation needed, the station operates in oil heating mode, or in thermal vacuum mode, filtering and cleaning the oil.

Specifications of the unit for oil reclaiming and oil degassing can be found here. Use the “Contact” tab to receive buying advice on the CMM-0.6.

El Paso, Texas: CMM-12R Regeneration Unit Gets Ready to Regenerate Transformer Oil!

December 17, 2015NewsCMM-12R, El Paso, GlobeCore, oil regeneration, transformer oil, USA

On 15 November 2015, in the city of El Paso, Texas, USA, GlobeCore employees completed the commissioning and start-up of a new GlobeCore CMM-12R oil regeneration unit.

This CMM-12R unit is designed for the complete regeneration of dielectric transformer insulating oil by removing moisture, contaminants and dangerous acids.

The GlobeCore CMM-12R unit processes insulating oil by directly hooking up to the power transformer and has a flow rate capacity up to 4 m3/1059 gals. per hour. The CMM-12R can process oil on an energized transformer, or with the transformer offline.

The CMM-R12 is able to perform oil regeneration operations on site. The unit will remove water, moisture, and contamination from the windings and solid insulation utilizing a Fuller’s Earth renewable sorbent. The sorbent itself can be reactivated many times eliminating the need to stop the regeneration process to unload and reload sorbent. Use of the GlobeCore Process regeneration technology can extend the service life of the electric power transformer up to 20 years and beyond.

**Parameters of Transformer Oil Processed with the GlobeCore SMM-12R Type Unit**

No.	Parameter description	Value
1	Filtration rating, micron, not more	3
2	Acid number, mg KOH/g in accordance with IEC 296; ASTM D-664	0.01
3	Corrosive sulfur as per ISO 5662; ASTM D-1275	absent
4	Surface tension, N/m, at 25ºС in accordance with ISO 6295; ASTM D-2285	45
5	Dielectric loss tangent at 90ºС in accordance with IEC 247; ASTM D-924	0.001
6	Oxidation stability. Acid number, mg KOH/g in accordance with IEC 1125А; IEC 1125B; IP-307	0.2

Please view our small photo report on the results of the start-up of the CMM-12R unit in El Paso, Texas, USA.

The Functions of Transformer Oil And Oil Restoration Methods

November 30, 2015Case Studies Of Oil ReclamationRestoration Methods, transformer oil

Transformer oil is a petroleum product that is used as a heat transfer medium in the transformer’s core and windings as well as an insulating fluid preventing short circuits and arching inside the transformer.

One of the important parameters of transformer oil is viscosity. Higher viscosity reduces the oil’s heat dissipation efficiency. The oil you are using, or want to use, should be checked for compliance with the required specifications before using the oil in a transformer.

Dielectric properties of the oil are defined by several parameters: dielectric strength, acidity, dissipation factor, particulate matter content, the content of water and water soluble acids, alkali, and flashpoint. The established parameters must not fall below the required specifications. Critical limits are usually given in regulatory documentation and will reflect national and international industrial standards.

Why does the transformer oil degerade over time?

During the operation of a transformer, several adverse factors influence the transformer oil that cause contamination, ingress of moisture and oxidation. The result is the progressive degradation of the dielectric fluid that includes both the chemical and physical properties the oil. The adverse elements affecting the oil are oxygen, high temperature and metal salts that become the catalysts of the detrimental oxidation process.

Degraded transformer oil cannot function correctly; it must be either replaced or regenerated using specialized equipment.

Replace or Restore?

Simple replacement of old oil with new oil does not completely solve the transformer’s existing problems entirely. When used oil is drained from the transformer, contamination will remain in the tank, core, winding, and solid insultaion. The remaining contamination will accelrate the degradeation of the new oil. Additionally, the remaining contamination will continue to harm the solid insulation.

Once the oil has been drained from the transformer, the old oil must be disposed of properly. It cannot be simply dumped into the ground or water.

Oil products are a hazardous waste pollutant. Used oil will disrupt and harm the lives of animals, fish and birds and cause serious diseases in humans that include cancers. Properly disposing of used oil is mandatory, and expensive.

A less expensive alternative is the restoration of old transformer oil. Restoration will extend the service life of the oil without the need to replace the oil and is free from the many drawbacks of removing and replacing the used oil. Some methods of restoration include drying, purification and regeneration.

Transformer oil can be purified by removing particulate matter and moisture through the use of centrifuges and filters. The oil can be dried by sorbent materials with high water adsorption and retention such as zeolites and silica gels.

Essentially, regeneration involves the completerestoration of oxidized oil by removal of the aging products.

The GlobeCore Soluton

GlobeCore offers comprehensive oil purification solutions with simultaneous purification, drying and regeneration of transformer oil. This multifaceted approach facilitates complete restoration of the degraded performance of the oil making it suitable for continued use without the need for removal and replacement.

GlobeCore Process Provides the Following Benefits:

reduce need to purchase of new oil;
eliminate need to dispose of old oil;
reduce and/or eliminate the storage facilities required for collection and storage of used oil;
improves power transformer reliability; and
greatly decreases the chance of oil polluting the environment.

GlobeCore is one of the world’s leading manufacturers of equipment for processing of transformer oil, turbine oil, industrial oil, transmission fluids and other types of used oil.

Dissolved Gas Analysis of Transformer Oil

September 22, 2015Case Studies Of Oil ReclamationAnalysis, Dissolved Gas, transformer oil

In today’s modern electric power industry, transformer oil sampling and analysis has begun to enjoy wide popularity. A good oil analysis program provides equipment owners the ability to determine the current condition of a transformer and schedule prevetive maintenance so as to avoid possible failures in future. In addition, the assessment of the transformer’s potential service life requires performing a dissolved gas analysis of the dielectric insulating oil in order to have a complete picture of the health of the transformer.

The aging of dielectric insulating materials and other parts inside a transformer leads to the creation of harmful and unwanted gases. A thorough analysis of these gases that are generated in a transformer is a necessary tool in performing a comprehensive preventive maintenance service on the transformer.

Generally speaking, there are a lot of methods available to analyze the content of gases in oil, but a dissolved gas analysis is preferred since only a dissolved gas analysis can provide the truest and most accurate results. This analysis process consists of sampling and analyzing the oil to determine the kind and amount of gases in the oil.

According to ASTM D3613, ASTM D3612, and ANSI/IEEE C57.104 standards, a dissolved gas analysis of transformer oil should be performed every year so that year to year results can be compared and so that problems can be identified early.

This article considers the possible ways of interpreting the results of the annual analysis. Electrical perturbations and thermal destruction will cause the creation of gases in transformers. It is also important to remember that some gases are formed in a transformer even at normal operating temperatures and under normal conditions. It is therefore, important to perform a dissolved gas analysis annually.

The composition of dielectric insulating oil contains hydrocarbon molecules that break down into carbon-hydrogen and carbon-carbon compounds when subjected to thermal and electric failures. The breakdown process generates atoms of hydrogen and hydrocarbon fragments that create unwanted gases. Additionally, the slow degradation process of cellulose insulation results in the production of such gases as methane, hydrogen, and carbon monoxide. It is temperature and the amount of material that determine the speed of gas formation. A larger amount of cellulose insulation at normal temperatures will produce the same amount of gases as a smaller amount of insulation at higher or more extreme temperatures. That is why it is essential to check the content of dissolved gases in oil regularly.

After a thorough analysis of the samples taken, one should determine the level of each unwanted gas found in the oil. Large deviations from the normal/accapatable values of gas concentration in the oil can indicate potential future failures in the transformer’s operation. The table below shows the recognized values for gas concentration provided by ANSI/IEEE C57.104.

Gas description	Key gas concentration (in ppm)
Gas description		Normal limits (<)	Action limits (>)	Potential fault type
hydrogen methane acetylene ethylene ethane carbon monoxide carbon dioxide Total combustibles	H2 CH4 C2H2 C2H4 C2H6 CO CO2 TDCG	150 25 15 20 10 500 10,000 720	1,000 80 70 150 35 1,000 15,000 4,630	Corona, arcing Sparking Arcing Severe overheating Local overheating Severe overheating Severe overheating
This table is derived from information provided by ANSI/IEEE C57.104

If the results of dissolved gas analysis show that the amount of gas has increased, it is recommended to carry out additional testing to confirm the obtained results and to determine if the values are still increasing. If after rechecking, the results still show that the values are above the acceptabe limits, a transformer should be subjected to a thorough offline inspection.

If the gas concentration in the oil has increased, other methods such as Duval’s Triangle Model, Doernenburg ratios and Rogers ratios should be applied to evaluate the potential problems in the transformer’s operation.

Taking everything into consideration, we should say that dissolved gas analysis of transformer oil makes it possible to predict and prevent the possible breakdown of equipment. If there has been a sharp increase of unwanted gas concentration in the oil, it is desirable to use diagnostic techniques to detect the nature and cause of the possible problems.

In conclusion, we have determined that the majority of transformer breakdowns are caused by the degradation of the oil’s performance characteristics. With this in mind, GlobeCore’s engineering department has developed the CMM line of units that are designed to de-gas and purify transformer oils by removing particulate matter, water, moisture, gases and other contaminants. GlobeCore’s equipment has enjoyed wide acceptance and excellent results in more than 70 countries around the world.

Transformer Oil Restoration Methods

September 6, 2015Case Studies Of Oil ReclamationRestoration Methods, transformer oil

In high-voltage equipment, transformer oil is used to:

quench an arc of a switching device;
cool down the heated parts of a transformer;
isolate conductive parts from non-conductive ones;
protect the transformer’s solid insulation from moisture penetration; and
monitor the condition of the transformer’s solid insulation as a diagnostic tool;

Transformer oil should possess the necessary characteristics to transfer heat properly. In particular, we are talking about a low viscosity that allows a substance to penetrate to each and all holes and spaces and perform a heat exchange function properly. Additionally, a lower viscosity favors the operation of circulating pumps, significantly facilitating their operation. Transformer oil must have a high flash-point of at least between 135 to 145ºС that provides smooth operation under overload conditions.

Additionally it must have a high dielectric strength that is determined by testing and the “breakdown voltage.” The following statement is true: the higher the voltage class of the equipment is, the higher the requirements for its breakdown voltage will be. This value greatly depends on the mechanical impurities, moisture and sludge that can accumulate in the oil during the continuous operation of the high-voltage equipment.

Such factors as sunlight, high electric field strength, air humidity, aging of solid insulation and inter-winding faults accelerate the oxidation of transformer oils.

As the time goes by, oil’s characteristics degrade and they less able to perform their functions. In practice therefore, oil is restored to its original condition and then placed back into service which allows for multiple and continued use of the product without replacement.

Physical methods of transformer oil restoration contribute to the removal of solid impurities, micro-droplets of water and resinous and coke-like matter. Low-boiling point impurities are removed by evaporation. Transformer oil can be processed in a field of force where the forces can be of gravitational, centrifugal, electrical, magnetic or vibrational in nature.

The physical methods of oil’s restoration may also include filtration, vacuum distillation, and water flushing. The simplest method of transformer oil purification is considered to be sedimentation since the removal of water and mechanical impurities are performed by the natural sedimentation process that is influenced by gravitational forces. Sedimentation is considered to be an individual purification method as well as an intermediate one. It depends on the original contamination level of the product and the amount of time allowed for its processing.

The main disadvantage of such an approach is that it requires a lot of time for complete oil purification and then can only remove big particles with a size of between 50 to 100 microns.

Filtration is a removal of mechanical impurities and resinous compounds by passing oil through filtration barriers. There are two types of filters: screen-type and porous type. Most often, filters are made of metal and plastic mesh fabric, felted fabric, paper, composition material and ceramics. To improve the quality of transformer oil purification, the system may be equipped with both coarse-mesh and fine-mesh filters working together as a complete filtration system.

Centrifugal purification is the removal of mechanical impurities and water with the help and force of centrifuges. It consists in the separation of different fractions of non-homogeneous mixtures influenced by centrifugal forces.

Physico-chemical methods of transformer oil restoration are widely applied and include coagulation, adsorption and selective purification.

The ion exchange purification method is a kind of adsorption purification. Coagulation means a growth of small contamination particles with a help of electrolyte of organic and non-organic origin, surface-active agents, and hydrophilic high molecular compounds. With the help of coagulation, it is easier to retain big size impurities. The efficiency of such a purification method depends greatly on the amount of coagulant introduced, the current temperature, blending process and the time in contact with oil. In practice, coagulation lasts no longer than between 20 and 30 minutes. After that, big particles are separated by filtration, sedimentation, aor centrifugal purification.

Adsorption purification is carried out with the help of some substances called adsorbents that retain contaminants. Such naturally-occurring substances as bauxite, zeolites, bleaching clays as well as substances obtained by artificial means (silica gels, alumosilicates, synthetic zeolites, aluminum oxide ) may be used as adsorbents.

The disadvantages of such an approach include the need to dispose of a great amount of waste sorbent which is dangerous for the environment. There are however, technologies that are now able to reactivate the sorbent directly in the transformer regeneration equipment thereby elminating the need to dispose of hazardous waste sorbent materials. It is not surprising therefore, that this highly advanced, environmentally friendly technology is offered by GlobeCore.

Ion exchange purification is based on the ion-exchange resin that is able to retain impurities that have the potential to dissociate and separated into ions. Purification is realized by blending ionites with waste oil or using a percolation method (waste oil is passed through a column, filled with ionites). The ion exchange results in the change of ions in a space lattice of ionite by contaminated ions. It stands to reason that the performance characteristics of ionites degrade. They may be restored by flushing them with a solvent, drying or activation with a caustic-soda solution.

Ion exchange purification allows for the removal of acid compounds from oil and at the same time retains resinous substances. A selective purification is a selective dissolution of some contaminants that degrade the characteristics of transformer oil. Such substances as furfural, phenol, nitrobenzene, acetone, and cetone. Chemical methods of transformer oil restoration are based on the interaction of impurities with the introduction of reagents. After all changes are completed, we can obtain substances that can be easily removed from the oil product. This approach includes acid and alkali purifications, oxidation with oxygen, hydrogenation, purification and drying with the help of oxides, carbides and hydrides of metals.

The following are the most widespread methods of purification:

Sulphuric acid refining is the processing of transformer oil by a concentrated solution of sulphuric acid. Acid sludge is considered to be a by-product of this process that is very dangerous and is difficult to dispose of. Another disadvantage of sulphuric acid purification is that polycyclic arenes and high toxic chlorine compounds are not removed from the waste material.

Hydrofining is characterized by a greater ecological cleanliness when compared with sulfuric acid refining and adsorption purification. It does however, have an undeniable disadvantage as this method requires a great amount of hydrogen and the highest level of economically-viable efficiency of 30 to 50 thousands of tons per hour.

Todays, it is very difficult to distinguish one method that is the most appropriate in each specific case. Therefore, equipment designed for transformer oil restoration, as a rule, operates on a complex of different methods. Thus, it makes it possible to restore different brands of transformer oils and with different levels of contamination.

The schedule of transformer oil maintenance oil type transformer maintenance

June 16, 2015Case Studies Of Oil Reclamationdielectric strength, equipment, GlobeCore, oil degassing, oil maintenance, oil reclaimer, oil reclamation, oil reclamation systems, power transformer, reclaim oil, regeneration, testing, transformer oil, transformer oil reclamation

oil type transformer maintenance

The frequency of transformers maintenance depends on the importance, design features and durability of transformers. The first step towards a preventive maintenance program is testing. Testing helps us to determine when a treatment is necessary.

WHY DO WE NEED TO CHECK TRANSFORMER OIL?

Transformer oil is an insulator between the metal parts of the transformer and the wiring within the tank. Over time, the oil can be contaminated with moisture or create combustible gases. By sampling and testing that oil, we can plan repairing or replacing the transformer before a failure occurs.

Maintenance Schedule for Oil Filled Power Transformers

Maintenance or Test	Recommended Interval	Reference
Transformer physical inspection	Annually
Leakage of oil and reading of MOG (Magnetic Oil Gage) of tanks	Daily	In case of unsatisfactory oil level in the MOG, oil to be filled in transformer and also the transformer tank to be checked for oil leakage. If oil leakage is found take required action to plug the leakage. If silica gel becomes pinkish, it should be replaced.
Dielectric strength test (BDV) and moisture content (PPM).	Annually	A dielectric strength is a measure of the voltage which is conducted by the transformer oil. At times it is the presence of contaminants which conduct electricity faster than the oil which in turn lowers the dielectric breakdown voltage
Neutralization test	Annually	This test which is carried out to ascertain the level of acid which is present in the oil. When oxidation occurs in the transformer oil, it leads to build-up of acid.
Dissolved Gas Analysis Test (DGA)	Annually for 132 KV transformer, once in 2 years for the transformer below 132 KV transformer and in 2 years interval for the transformer above 132 KV transformer.	It helps to analyze the gases which are present in the transformer oil.
Bushings– check of oil level	Weekly	If it is required, the oil to be filled in the bushing up to correct level. Oil filling to be done under shutdown condition.
Bushings –visual inspection	Annually
Bushings – visual inspection and cleaning	5 years
Interfacial tension test		This is a test which is carried out to detect the presence of polar compounds such as paint, varnish and paper.
Tan & delta test	One in two years	Finally the presence of water too is measured as water can decrease the dielectric breakdown voltage of the transformer oil
Colour test		This test indicates aging, quality and the presence of contaminants in the transformer oil.
Transformer excitation current test	5 years
Insulating oil – DGA, physical, and chemical tests	Anually
Top oil and winding thermometer Inspection	Anually
Oil level indicator operation	5 years
Sudden pressure relay	5 years

oil type transformer maintenance

So, for getting high performance and long functional life of the transformer, it is desired to perform various maintenance activities. GlobeCores’s oil reclamation equipment will keep your transformer oil in the best condition, providing with oil degassing, water and solids removal as well as acids reducing. It’s a fantastic transformer life!

GlobeCore Has Presented its Equipment in Armenia

June 16, 2015Newsequipment, GlobeCore, oil reclaimer, oil reclamation, oil reclamation systems, power transformer, reclaim oil, transformer oil, transformer oil reclamation, used oil

In February, GlobeCore staff delivered another presentation on its equipment.

GlobeCore managers visited Yerevan in order to meet with representatives of the power industry in Armenia. The peculiarities of equipment, designed to purify and regenerate transformer oil and maintain power transformers were the main topics of the lecture. All the questions arouse were satisfied.

After the samples of used oil were processed on the GlobeCore unit, the people present had no doubts that GlobeCore equipment was able to solve even the most complicated tasks. It is easy-to-use and eco-friendly, reduces operational costs and valuable raw material.

In general, both parties were very satisfied by the results of the meeting. GlobeCore has gained new experience communicating with specialists of the electric power industry and the representatives of Armenia have received a great possibility to solve the problems, accumulated for decades.

Transformer Damage and Oil Regeneration/Oil Reclamation

June 9, 2015UncategorizedCMM-R, drying, equipment, installation, oil, oil contamination, oil purification, oil reclamation, oil recycling, oil regeneration, oil treatment, power consumption, power transformer, Recycling, transformer damage, transformer oil, types, used oil

An electric power transformer Damage is one of the most important elements of the modern electric grid no matter where in the world a particula grid may be located. Transformer failures result in significant financial expenditures, and will require the transmission company to buy new transforners or repair the damaged ones at significant cost and service interuptions.

Many historians note that there was great industrial boom observed in the first decade followintg the end of World War II. At that time, there was a rapid increase in electric power consumption. To meet the growing demand for electric power, new transformers had to constantly be put into operation. Since that time, mant of the older transformers have become outdated and pose a big risk of unscheduled service interuptions.

Older transformers’ obsolescence however, is not the only problem facing the modern power grids. The power loads on the obsolete transformers are increasing because of ever increasing power consumption. It requires significant expenditures to replace the broken or obsolete transformer since the price for a new transformer is very high.

It is therefore, advisable to take measures to extend the service life of transformers already in service. To succeed in undertaking a sucessful preventive maintenance program, one should understand the nature of the failures that make transformers unserviceable in the first place.

In 2003, the International Association of Engineering Insurers (IMIA) started to explore the reasons for transformer failures servicing the combined USA power grids. The results were rather interesting. Table 1 shows the economic losses caused by different types of transformer failures.

Table 1

Economical Losses Caused by Different Transformer failures

Nature of Failure	Amount of Cases	Economical Loss in $
Insulation defects	24%	149,967,277.00
Problems with designing, material or installation	22%	64,969,051.00
Unknown failures	15%	29,776,245.00
Oil contamination	4%	11,836,367.00
Overloading	5%	8,568,768.00
Inflammation/explosion	3%	8,045,771.00
Network overvoltage	4%	4,959,691.00
Operational failures	5%	3,518,783.00
Water ingress	2%	2,240,198.00
Poor contacts	6%	2,186,725.00
Lightning stroke	3%	657,935.00
Insulation moistening	1%	175,000.00
In total	94%	286,628,811.00

It is not an overstatement to say that if proper and timely preventive maintenance of the insulating systems is performed, many, if not all transformer failures can be prevented. The insulating system of the power transformer consists of bith solid and liquid insulation. The solid insulation is made of hygroscopic material (cellulose) also known as “Kraft Paper.” The liquid insulation features a dielectric fluid known as transformer insulating oil. In general, these two kinds of insulation are interdependent, but also help to contaminate each because degradation products from the solid insulation may get into oil and oil oxidation sludges may penetrate into the solid insulation from the oil. Simply changing the transformer oil therefore, will not completely resolve the problem of restoring and cleaning the entire insulation system. Unfortunatelt, oxidation products are accumulated in the cellulose insulation and are not removed when oil is simply changed. And when only an oil changed is performed, these oxidation products will migrate get into new oil accelerating the aging process of the new oil and shortening its effective service life. Additionally, the contamination that remains in the solid insulation will continue to degrade and damage the Kraft Paper leading to transformer failure.

This problem may be solved with the advanced GlobeCore regeneration technologies. The GlobeCore mobile oil recycling stations, designated as the CMM-R line of equipment may be connected to either an energized or non-energized transformer. In such a way, oil is circulated through a closed path: used oil flows to the oil treatment station and goes back to the transformer being cleaned and restored. The contaminants resulting from the aging process are washed out due to the constant circulation. This advanced type of equipment performs a complete oil regeneration service and removes all contamination for the transformer core, windings and solid insulation.

GlobeCore mobile oil stations perform the following operations:

filtration with or without heating (processed oil is of 9th ISO 4406 purity class and with nominal filtration fineness, ranging from 0.5…1 micron);
dehydration (the moisture content of the processed oil is no more than 5 g/t (5ppm);
degassing (volumetric gas content of the processed oil is no more than 0.1 %);
increase the dielectric breakdown voltage (no less than 70 kV (kilovolt));
drying of electrical equipment and oil purification simultaneously;
regenerate insulating oil, using bleaching clay;
vacuum transformers and other electrical equipment;
remove acids;
remove soluble oil decomposition products;
lighten insulating oil; and
restore oxidation and gasification stability;

The GlоbeCоre technologies provide for service life extension of transformers and reduction of financial expenditures on maintenance. Save money with GlоbeCоre!

Reliability of Low Voltage Power Transformers

June 7, 2015Case Studies Of Oil Reclamationlow voltage power transformers, oil reclaimer, oil reclamation, oil reclamation systems, Performance Characteristics, reclaim oil, regeneration, reliability, transformer damage, transformer oil, transformer oil purification, transformer oil reclamation, Transformer Oils

GlоbeCоre’s oil reclamation technology has been proven to cost effectively regenerate transformer oil thereby increasing the operational reliability of electric transmission equipment.

Before electric grid restructuring started, units with a voltage of between 110 and 500 kV (kilovolt) had constituted the greatest part of the fleet of transformers. But the things have recently changed, today power companies routinely use transformers with voltage that is less than 110 kV with the majority of the transformers having a capacity of less than 35 kV.

Table 1 analysis of the reasons for equipment damage depending on the point of fault.

Table 1

Damage Sources for Transformers with Voltage up to 35 kV

No.	Type of Fault	Rate of the total % of faults
1	Winding faults	19
2	Bushing insulator	3
3	Insulation faults	21
4	Insulation moistening	8
5	Oil	5
6	Voltage regulators	23
7	Contacts in windings	15
9	Other	6

As we can see, the greatest amount of damage is the result of insulation faults. That is why the condition of transformer oil is of such importance. The efficiency of the entire insulation system (both solid and liquid) largely depends on the quality and condition of the dielectric transformer oil. Such factors as temperature extremes, interaction with the atmospheric oxygen, and the accumulation of emulsion water have a negative impact not only on the performance characteristics of oil, but also on the condition of the solid insulation. As a result, transformers break down prematurely even though their service life should be much longer.

Unfortunately, once the transformer has experienced a catastrophic failure, there is only one solution to this problem. The failed transformer willl have to be replaced by a new one. But, such a strategy requires significant capital expenditures and leads to reduced profits and inefficient operations.

The solution to this problem is to call GlоbeCоre who is in the business of designing and producing equipment for purification and regeneration of transformer oils.

GlobeCore promotes and adheres to the principle of “preventive maintenance.” That means that the causes of transformer damage are prevented in the first place during transformer servicing. It is transformer oil purification that helps insulting oil maintain its performance characteristics at the proper level and slows down the process of its aging.

GlоbeCоre produces equipment that allows for complete processing of transformer oil (purification, dehydration, and degasifying) to restore the original performance characteristics of the dielectric oil.

GlоbeCоre equipment is also very eco-friendly: there are no harmful discharges into the air since it uses the sorbent that can be reactivated to prevent the penetration of oil residues into water and soil. The service life of transformers with a voltage up to 35 kV may be extended by 10 years if negative impacts are reduced.

Oil Reclamation as a Method of Improving Power SubStations

June 1, 2015Case Studies Of Oil Reclamationmethod of improving power stations, new technology, oil reclaimer, oil reclamation, oil reclamation equipment, oil reclamation machine, oil reclamation plant, oil reclamation systems, oil reclamation unit, Power SubStation's Oil Reclamation, power transformer, reclaim oil, transformer oil, transformer oil reclamation, transformer oil regeneration, used oil

Uninterrupted transformer oil regeneration

Industry is always looking for new ways in how to improve the efficiency of existing electric power transformers since the price for new equipment has been increasing significantly in the past twenty years. Distribution substations and the transmission network are constantly working at peak or near peak capacity and that leads to much more rapid transformer wear and aging. Especially hard hit is the transformer’s liquid and solid insulation.

If the insulating system is in bad condition, the dielectric properties of insulating oil will be reduced. For such a prolem, GlobeCore has developed technology for the regeneration and purification of contaminated oil that restores the oil to its original new like condition. Using this advance new technology, oil is circulated through the special regeneration columns filled with Fuller’s Earth sorbent materials. Contaminated oil flows to the oil station and is sent back to the transformer in a clean, new like condition.

Since oil is continuously circulated through the unit, the contaminated oil residues are washed out from the transformer. Fuller’s Earth (a naturally-occurring sorbent) absorbs impurities and contaminants. The regeneration time will depend on the amount of oil that needs to be regenerated and the degree of its contamination.

GlоbeCоre equipment is desiged to work on energized transformers so there will be no, or minimal service interuptions. Another benefit of GlobeCore equipment is that its mobility allows the operators to serve multiple pieces of equipment in remote locations without having to evacuate the transformer to a repair or maintenance facility.

GlobeCore regeneration technology allows transformer services companies to:

(1) restore oil to its original like new condition;

(2) extend the service life of transformers and improve their efficiency;

(3) carry out “preventive maintenance” in order to eliminate the need for corrective mainatenance;

(4) greatly reduce the need to by new oil;

(5) eliminate the need to dispose of used oil; and

(6) eliminate the risk of service trouble during power equipment operation;

GlobeCore technology provides for transformer service life extension, reduction in financial expenditures and improvement of equipment efficiency. Contaminated oil residues significanly reduce the service life of windings and operational reliability of transformers. Aging of oil-cellulose insulation may lead to irreversible consequences during its expected service life.

GlobeCore technology increases transformer service life thereby reducing operating costs and improving operational reliability.

Contaminated oil residues reduce significantly the service life of windings and the transformer’s operational reliability. Despite the fact that oil-cellulose insulation may be used for more than 25 years, contaminated oil will cause premature failure of the transformer long before the transformer is ready for retirement.

Factors that have a negative impact on the insulation system of the transformer

GlobeCore’s Equipment is Environmentally-Friendly

Oil Regeneration is better than an oil change

It is better to regenerate oil than to simply change it. Products of degradation that have accumulated in the transformer’s solid insulation will get into the new oil within a few months of the oil change. As a result, the new oil will lose its performance characteristics much more rapidly than with the GlobeCore rengernation process.

GlobeCore equipment is considered to be revolutionary since Fuller’s Earth (the active adsorbent filtering system) is able to absorb products of degradation. Additionally, oil that is regenerated with GlobeCore equipment is much more resistant to aging. When only changing the oil, there is always up to 15% of the contaminated oil left in the transformer that will accelerate the new oil’s aging.

Due to advanced GlobeCore technology, all contaminated oil residues are washed out of the transformer by the hot oil being circulated through a closed loop that includes the regeneration equipment and the transformer.

GlobeCore’s regeneration technology is eco-friendly does not generate hazardous waste while regenerating transformer oil and other industrial fluids and oils. The Fuller’s Earth, used in the GlobeCore CMM-R line of equipment, absorbs all impurities and is reactivated directly in the equipment precluding the need to stop and dispose of used sorbent during the processing job. Each load of Fuller’s Earth will last up to 300 regeneration cycles before needing to be replaced.

GlobeCore CMM-R line of equipment

GlobeCore technology distinguishes itself through the following features:

Continuous autmoated and remote internet operation;
Operating Cost reductions;
Long-lasting oil and fluid purification effect;and
Complete removal of contamnants from oil and solid insulation.

Removing Contaminants from Transformers

If your comapny does not perform reglarly scheduled preventive maintenance, unwanted sediments and other contaminants will accumulate in the crital areas of your transformers. As a result, the performance characteristics of dielectric insulating oil will be reduced and the likelyhood of a transformer insulation failure will be greatly increased.

The GlobeCore Process of regeneraing dielectric insulating oil is able to dissolve and remove sediments at high temperatures from the transformer’s core and solid insulation. Even previously accumulated sediments may be dissolved and removed from the entire transformer.

The following table shows the limiting values of transformer oil that indicate when it is necessary to regenerate the transformer’s dielectric oil.

Performance Characteristic	Value
Acid number	>0.08 mgKOH/g of oil
Dielectric losses at 90⁰C (40 and 60 Hz)	>0.2 for power transformers and reactors with voltage more than 170 kW.
Dielectric losses at 90⁰C (40 and 60 Hz)	>0.50 for power transformers and reactors with voltage less than 170 kW.
Inhibitor content	Inhibitor additve concentration <.4%
Acidity and surface tension correlation	Acidity > 0.6 mgKOH/g of oil and surface tension <30 mN/m
Sediments	perceptible sediments
Additionally, IEC Standard 60422 recommends to regenerate oil if the performance characteristics of the oil are reduced.

Benefits of Preventive Maintenance

The degradation effects suffered by the solid insultaion found in the modern oil filled electric power transformer are irreversible. Solid insulation degradation cannot be repaired through any modern regeneration technologies on the world market today. Regeneration therefore, should be considered as a preventive mantenance procedure as opposed to a corrective maintenance procedure. The GlobeCore “Service Life Extension Program” uses advanced modern technolgy to remove moisture and contaminants that degrade the transformer’s solid insulation. It provides for the service life extension of the transformer by removing the progressive aging contaminant from the solid insulation.

GlobeCore CMM-R oil processing units

The table below shows the results of the physicochemical analysis of transformer oil that has been regenerated using the GlobeCore CMM-R oil processing units.

The Results of Physicochemical Analysis of Transformer Oil

№	Characteristic	Before regeneration	After regeneration	IEC 60296 standard
1	Physical form	Cloudy, dark brown	Pure, clear	Pure, without sediments
2	Acid number, mg KOH/g oil	0.63	0.01	0.01
3	Corrosive sulphur	+	none	none
4	Moisture content, ррm, no more than	170	5	30-40
5	Breakdown voltage, kW	11	73	30-70
6	Dielectric dissipation factor at 90ºС, %	4.0	0.001	0.005
7	Gas content, %	12	0.1	–
8	Surface tension at 25ºС, mN/m	22	45	40
9	Mechanical impurities in microns	50	0.2	–
10	Oxidation resistance test:– acid number mg of KOH/g oil	–	0.2	1.2

After regeneration, oil that has been used for many years is restored to its original new like condition and its dielectric properties are kept stable during many years of future service.

GlobeCore regeneration units substantially extend the service life of electric power transformers.