Electrical equipment performance and protection are greatly enhanced by electro-insulating varnishes. The purpose of these specialized coatings is to improve durability and prevent short circuits by insulating electrical components. These varnishes protect electrical systems from moisture, dust, and other environmental elements, extending their lifespan and dependability.
KO-921 and KO-916 are two common varieties of electro insulating varnishes. Both have great insulating qualities and are simple to use, which makes them popular in a variety of industries. Knowing the distinctions between these two varnishes will assist you in selecting the best one for your particular requirements.
KO-921 varnish is renowned for having exceptional durability and heat resistance. It is frequently utilized in hot conditions where more conventional insulating materials might not hold up. For electrical motors, transformers, and other high-stress applications, this varnish offers strong protection.
Conversely, KO-916 varnish provides better flexibility and resistance to moisture. Because of this, it is ideal for usage outside or in high-humidity settings. Its capacity to keep its insulating qualities under a range of circumstances guarantees the safety and functionality of electrical components.
The particular needs of your application must be taken into account when choosing an electro-insulating varnish. The distinct compositions of KO-921 and KO-916 meet various operational and environmental requirements. You can choose wisely and extend the life of your electrical equipment by evaluating the technical specifications and comprehending the goals behind them.
| Type | Details |
| Definition | Electro insulating varnishes are coatings that protect electrical components by providing insulation and resistance to moisture, heat, and chemicals. |
| Usage | These varnishes are applied to motors, transformers, and other electrical devices to enhance performance and longevity. |
| KO-921 Composition | KO-921 is a silicone-based varnish known for its high heat resistance and excellent electrical insulating properties. |
| KO-916 Composition | KO-916 is another silicone-based varnish, offering good thermal stability and dielectric strength, suitable for a variety of applications. |
| Purpose | The primary purpose is to protect electrical components from environmental factors and improve insulation. |
| Technical Parameters | Both KO-921 and KO-916 have high temperature resistance, good dielectric strength, and strong adhesion to various surfaces. |
In order to ensure safe and dependable operation, electro-insulating varnishes are crucial for shielding electrical components from moisture, chemicals, and electrical leakage. This article explores the uses and compositions of two common varnishes, KO-916 and KO-921. It describes their specific functions, important technical details, and useful advice for efficient use. Gaining knowledge about these varnishes will help you select and use the appropriate insulating solution for a variety of electrical and electronic applications.
- The need to use electrical insulating varnishes
- Types of varnishes for electrical insulation
- Methods of varnishing devices and structural elements
- Applying varnish and vacuum
- Video on the topic
- A little about LKM
- No. 132 Why it is impossible to whiten reinforced concrete supports of power lines interesting for an electrician
- Electro insulating paints and varnishes for impregnation of windings (BT-99, ML-92, KO-916, GF-92)
The need to use electrical insulating varnishes
The following are the objectives of electrical insulating varnish impregnation:
- Strengthening heat from the inside of the winding (the heat conductivity coefficient of 0.003, and the electrical insulation varnish is approximately 0.2-0.3, t.e. Varnishes are carried out heat about 100 times more efficient than air, thereby reducing the temperature of electromechanism);
- Mechanical strengthening of electrical appliances and power tools, and increasing its resistance to vibration and movement;
- Reducing the penetration of external factors, such as: alkalis, acids, water, solvents, oils, etc., as well as a decrease in biological erosion;
- Reduction in ionization and partial discharges;
- Increasing the dielectric resistance of the insulation of the winding and the “correction” of defects of the primary insulating layer formed during winding.
Electro insulating varnish 921
The magnetic field’s action causes vibrations in electrical equipment. Electric motor rotors are subject to strong centrifugal forces. Windings of any motor: Internal stress and inertia act on power plants, ranging from the home blender to the turbine.
Types of varnishes for electrical insulation
Electrical insulating enamels and varnishes are two categories into which all of these insulation materials fall.
Electro insulating varnish
Based on the composition available for purchase:
- Bitumen;
- Melamino-alkidal;
- Based on organic compounds of silicon;
- Epoxesiefire;
- Glyftal with the addition of alkyd compounds;
- Based on epoxy.
Electro insulating varnish 921
It makes sense to group varnishes according to their chemical makeup and application technique. There are two types of typical electrical insulating impregnation varnishes: those that need solvents to dissolve them and those that don’t.
- Lacques based on solvents are a mixture of liquid polyester resins, epoxy alkids with sewing agents such as amino and phenolic resins. A characteristic feature of these varnishes is the presence of ~ 50% of volatile organic substances in their composition.
- Solvents during the drying process should evaporate, becoming a source of air pollution, rarely a source of energy after burning. The temperature class of these varnishes is b, f and sometimes h.
- Their advantage is the simplicity of application, usually low viscosity, resistance to pollution, very good storage stability, good flexibility of coatings. Disadvantages – high emission of volatile organic substances, long drying out, boiling in vacuum impregnation conditions.
- This varnish group also includes water -based varnishes, which sometimes differ in excellent operational properties after hardening, but always require maintaining the regime of high purity of lines and impregnated elements.
Electro insulating varnish 921
Reactive diluents, which are chemically incorporated into the polymer during paint drying, are responsible for the name of electro-insulating varnishes devoid of solvents.
Varnishes without solvents are classified as either varnishes with or without styrene, depending on the kind of reactive solvent that is used. These are solutions of unsaturated polyester or polyesmide resins in both situations.
Electric insulation varnish 916
Methods of varnishing devices and structural elements
The immersion method is the most straightforward way to process electrical insulating varnish. Because the impregnation varnish has a density higher than that of air, there is a pushing force at work that causes the varnish to penetrate the processed surface.
In certain instances, the varnish’s penetration results in less surface tension between the varnish and the winding wires’ surface stretch. This method’s low cost and ability to use varnishes based on solvents with high solvent vapor pressure are its advantages.
Electro insulating varnish 921
The risk of incomplete impregnation, particularly with regard to the wire windings with a silk braid, is the drawback of the immersion method.
- The further development of the immersion method is vacuum impregnation, it consists in the initial creation of a vacuum in an autoclave containing a soaked machine unit (wound stator or rotor), maintaining a vacuum for a given time and absorption of varnish into an autoclave under the influence of a vacuum created.
- This method, thanks to a good drying of a soaked device that removes most of the air from the inside of the winding, increases the buoyancy of the varnish, providing much more complete impregnation compared to the method of immersion, especially wirewash.
Tsaponlak
The method’s drawbacks include the installation’s high operating costs, the requirement for routine maintenance, and the increased requirements for the varnishes that are used (the lack of foam formation stems from boiling a mixture of solvents under low pressure).
Applying varnish and vacuum
The pressure-pressure method, a technological advancement of the vacuum method, is the most sophisticated way to impregnate devices.
There are four stages to the processing process:
- Heating the winding or other structural elements before its placement in autoclave;
- Drying in an autoclave in an intensive vacuum (~ 1 MBAR);
- The introduction of varnish into an autoclave and a cyclical creation of a vacuum;
- Reduction in vacuum and creating excess pressure to ~ 3 bar.
Tsaponlak
Even with high-haired impregnations, the best impregnation is achieved by the varnish seeping through the surface of the processed devices and inside the dried winding.
The method’s drawbacks include installation costs, the requirement for UDT supervision, and the need to use more costly varnishes devoid of solvents in order to prevent foaming varnish. Both large and small parts of machines can be impregnated using the previously mentioned techniques.
Electro insulating varnish 921
Electro-insulating varnishes are essential for guaranteeing the longevity and efficiency of electrical components by shielding them from external influences. These varnishes form an insulating layer that shields the parts from dust, moisture, and other potentially dangerous materials. In a variety of sectors, including electronics and automotive, where dependable operation is crucial, this protection is indispensable.
KO-921 and KO-916 stand out among the other varieties of electro insulating varnishes due to their distinct compositions and uses. Because of its exceptional moisture resistance and thermal stability, KO-921 is a great choice for applications involving high temperatures. However, KO-916 provides better adhesion and mechanical strength, which is advantageous for parts that need strong protection or are subjected to frequent mechanical stress.
It is crucial to comprehend the technical specifications of these varnishes in order to choose the best one for a given application. Power transformers, electrical motors, and other high-voltage equipment are ideal applications for KO-921 because of its exceptional dielectric strength and thermal endurance. Strong bonding capabilities and resistance to chemical exposure make KO-916 a popular choice for protective coatings on a variety of electronic components, including those in the automotive industry.
For best results, use these varnishes according to the recommended application and surface preparation methods. The surfaces that will receive the varnish application should be clean, dry, and free of contaminants. Different application techniques, such as brushing, spraying, or dipping, can be used, based on the component and the required protective layer thickness.
To sum up, electro insulating varnishes such as KO-916 and KO-921 are essential for preserving the functionality and integrity of electrical components. Users can choose the best varnishes for protecting their equipment and apply them efficiently by being aware of their compositions, uses, and technical specifications.
