Why is the paint on the outside of the enameled wire insulated?

The surface of the enameled wire is coated with a special layer of lacquer, which is called electrical insulating paint. It contains oils, resins, pigments, fillers and solvents. In order to meet the requirements of electrical insulation, the film structure of electrical insulating paint is different from that of general paint, it has a large resistivity, good thermal conductivity, and strong mechanical properties and good moisture resistance.

Because the resistivity of enameled wire is large, so its insulation performance is good, and the paint on the outer skin of enameled wire is usually polyester, polyurethane and other insulation materials, so it can not only play a protective role, but also play an insulating role. Enameled wire is a major variety of winding wire, which is composed of two parts: conductor and insulating layer, and the bare wire is annealed and softened, and then painted and baked many times. The lacquer on the outside of it can play an insulating role.

To improve the temperature resistance level and develop special-purpose enameled wire, composite insulation layer is generally used. Compared with single-coated enameled wire, composite coated enameled wire has the following advantages: to meet special use requirements, such as self-adhesive enameled wire for complex skeleton-free forming, refrigerant-resistant enameled wire for refrigerators and air conditioning compressors, etc., which can be met by composite coating structure; Through the composite of various insulating layers, its characteristics complement each other's strengths, improve and enhance the use of performance, to meet the requirements of use, such as polyester nylon composite coating enameled wire to improve the thermal shock performance and winding performance, suitable for hot impregnation process, can be used for motor windings that overheat due to overload; The cost of some enameled wires can be reduced, such as polyesterimide, polyamideimide composite coated enameled wire can replace a single coat of polyamideimide enameled wire, which can be greatly reduced.

Enameled wire is the main raw material of motors, electrical appliances and household appliances and other products, especially in recent years, the power industry has achieved sustained and rapid growth, the rapid development of household appliances, the application of enameled wire has brought a broader field, followed by higher requirements for enameled wire. For this reason, the product structure adjustment of enameled wire is inevitable, and the raw materials (copper, lacquer), enameled process, process equipment and testing methods are also urgently needed to develop and research polyamideimide composite enameled wire. Enameled wire for special purposes:

It refers to the self-adhesive enameled wire with certain quality characteristics, bare wire softened by annealing: it is mainly used for motors working in 180 and above temperature environments: polyurethane enameled wire (direct soldering), winding wire used in specific occasions, such as polyesterimide enameled wire, and then winding wire in working occasions such as polyesterimide and modified polyester enameled wire, such as polyester enameled wire.

That's the insulating varnish, which acts as an insulator. The insulating ability of this kind of insulating paint is stronger than that of ordinary paint or wire sheath, which means that a very thin layer can play a role in resisting the breakdown of the same voltage. Polyimide is currently the highest heat-resistant enamel among organic enameled wires, and its long-term use temperature can reach more than 220°C.

The paint was successfully developed by the United States in 1958. Polyimide enameled wire has high heat resistance, good solvent and freezer resistance. However, due to its high cost, poor storage stability and toxicity, it has affected its widespread use.

At present, the enameled wire is used in some special occasions, such as coal mine motors, space instruments and meters, etc. Polyamideimide paintPolyamideimide paint is the most comprehensive performance in the current enameled wire enamel, with high heat resistance, mechanical properties, refrigerant resistance and chemical resistance, so it is known as the king of enameled wire enamel. At present, the paint is mainly used for its unique properties, and is widely used as a topcoat for composite coating enameled wires, improving the heat resistance of composite lines and reducing costs.

At present, it is mainly used to coat refrigerant-resistant enameled wire in China, and this paint is produced in small quantities in China, mainly imported from the United States, Italy and Germany. <>

Insulation. Enameled wire is one of the main varieties of winding envy and empty wire, which is composed of two parts: conductor and insulating layer, and the bare wire is softened by annealing, and then painted and baked many times.

However, it is not easy to produce products that meet the requirements of the standard and meet the requirements of customers, it is affected by the quality of raw materials, process parameters, production equipment, environment and other factors, therefore, the quality characteristics of various enameled wires are different, but they all have four major properties: mechanical properties, chemical properties, electrical properties and thermal properties.

<> "Hello dear, I'm glad to answer for you, what is the reason for the poor inter-turn insulation of the enameled wire Answer: Dear, hello, it is that the paint film on the enameled wire is partially broken or the winding eggplant rubber mold is biased and the end of the winding extends long. Because the inner wall of the end cap is close to or touches the fault point after the end cap is covered, the insulation resistance of the winding is reduced.

To eliminate this fault, you should first determine which end of the motor is the fault. The judgment method is simplified: first install an end cover, and measure the insulation resistance of the winding with a 500V insulation resistance meter, if it is very low, it means that the winding at this end is faulty.

Then, remove this end cover, and then install the other end cover, measure the insulation resistance of the winding, if it is also low, it means that the other end is also faulty. In the process of disassembling and assembling the end cover, the rotor can not be installed. After determining the fault end, generally the end of the winding is slightly shaped, and coated with some insulating paint, if the problem is not solved, it can be easily touched on the outside of the end of the winding end and the inside of the end cover with a layer of film green shell paper, the fault can be eliminated, I hope my can help you!

Wishing you a happy <>

Summary. Hello dear, <>

1: The quality of enameled wire is poor, especially for thin wire, pinhole points are allowed in the wire standard, and it is easy to produce short circuit when winding.

2: The enameled wire is damaged during winding, such as the paint film is damaged, scraped, knotted, etc.

3: The solder joint pad paper is crushed or the solder joint is displaced.

4: There are burrs in the lead wire or solder joint, which breaks the insulation layer.

5: When using copper shielding, the interlayer insulation is not padded, and the shielding layer touches from end to end.

The consequences of poor insulation of transformer enameled wires.

Hello dear, <>

1: The quality of enameled wire is poor, especially for thin wires, pinhole points are allowed in the wire Nianmeng standard, and the first bridge of Rongzi is easy to produce short circuits when winding. 2：

Damage to the enameled wire during winding, such as damage to the paint film, scraping, knotting, etc. 3: The solder joint pad paper is crushed or the solder joint is displaced.

4: There are burrs in the lead wire or solder joint, which breaks the insulation layer. 5：

When using copper shielding, the interlayer insulation is not padded, and the shielding layer is used to touch each other.

Hello dear, <>

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The consequences of poor insulation of the enameled wire of the transformer may be caused by load or undervoltage, and the motor operating current is greater than the rated value when the voltage is lower than 360, which will burn out the three-phase winding. If there is a lack of one-phase electricity, the two-phase winding will be burned out. Damage to the insulation of the enameled wire causes a short circuit between turns.

It does not cause overpressure and undervoltage. I hope I can help you.

Categories: Education Science.

Analysis: a. Definition of enameled wire (self-adhesive enameled wire Non-self-adhesive enameled wire):

The production of enameled wire is to coat a high-purity, high-conductivity conductor with a layer of insulating coating, that is: conductor + insulating paint = non-self-adhesive enameled wire.

Conductor + insulating paint + adhesive layer = self-adhesive enameled wire.

Two. Classification and structure of wire rods:

1.According to the different materials of its conductors, it can be divided into:

Copper wire (copper), aluminum wire (AL), copper-clad aluminum wire (,2.).Classification according to the thickness of the insulating varnish:

2.Classification according to the thickness of the insulating varnish:

If the CNS (Chinese National Standard) or JIS (Japanese Industrial Standard) standard is used, the thickness of the insulating paint can be divided into 0 kinds, 1 kind, 2 kinds, and 3 kinds of wires, of which 0 kinds of wire insulating paint are the thickest, and 3 kinds of wire insulating paint are the thinnest;

If the IEC (International Electrotechnical Commission) standard is used, it is divided into Grade1, Grade2, and Grade3;

If the NEMA (International Electrical Manufacturers Association) standard is concerned, it is divided into type3

Because different customers have different requirements, different standards of wire can be selected.

Therefore, it must be judged according to the corresponding criteria.

PEI (Polyimide Polyester Enameled Wire) -- Grease with Polyester-imide resin as the main body.

The margin film is painted on the conductor; It has a heat resistance rating of 180 (class H).

UEW (Polyurethane Enameled Wire) -- Grease with polyester-thane resin as the main body.

The insulating film is painted on the conductor; Its maximum characteristics are that it can be directly soldered and has a heat resistance class.

130 (Grade B).

PEW (polyester enameled wire) - Polyester resin as the main body, grease as the insulating film, baked paint on the conductor; It has a heat resistance rating of 155 (class F).

AIW (polyimide enameled wire) -- polyamide-imide resin as the main body, grease as the insulating film, baking paint on the conductor; It has a heat resistance rating of 200 (H+).

3.According to the adhesive method, it can be divided into:

Alcohol threads --- wires that bond themselves under the influence of alcohol (e.g. lock).

Hot air wires --- wires that are bonded by heat (e.g., pei).

Dual-purpose wires --- wires that bond themselves under the action of alcohol or heat.

1. Everyone should have heard of the old first winding wire, which is what we often call magnet wire, and enameled wire is a kind of magnet wire.

2. Slowly heat and cool the bare wire, its hardness decreases and becomes soft, and then the bare wire is painted many times and baked with a shield, and the enameled wire is completed.

3. There are many types of enameled wire, no matter what the type is, or the quality is high, the enameled wire has certain performance.

The above is the content I have introduced to you about enameled wire, I hope it can be helpful to you.