The winding wire on the three-phase asynchronous motor is a conductive metal with an insulating layer, which is used to wind the coil winding of electrical products, its role is to generate a magnetic field through the current, to cut the magnetic force line to generate current, to achieve the mutual conversion of electrical energy magnetic energy, so it is also called electromagnetic wire.

The conductive core of the winding wire has round wire, flat wire, tape, foil, etc. Usually, copper wire, aluminum wire other metal wire is used as the conductive wire core.

At present, in addition to natural materials, the insulating layer of winding wire is mainly made of organic synthetic polymer compounds (such as acetal, polyester, polyurethane, polyester imide resin, etc.) inorganic materials (such as glass wire, alumina film, ceramics, etc.). Because the insulating layer composed of a single material has certain limitations in performance, some winding wires use composite insulation combined insulation. The winding wire on the three-phase induction motor can be divided into four categories according to the characteristics uses of the insulating layer, such as enamelled wire, wrapped wire, inorganic insulated winding wire special winding wire.

1, enamelled wire

The insulating layer of enameled wire is lacquer film, which is dried by coating insulating paint on the conductive wire core. It is characterized by thin, uniform smooth paint film, which is conducive to high-speed winding of coils, is widely used in small medium-sized motors, electrical appliances micro electrical electronic products. Enamelled wire can also be divided into the following types according to its long-term use temperature use characteristics:

Ordinary enamelled wire includes enamelled wire with a long-term use temperature of 155 ° C below, such as polyester, acetal, polyurethane, epoxy oil-based enamelled round (flat) wire.

High temperature resistant enamelled wire includes polyimide, polyester imide, polyester imide/polyamide, polyester imide/polyamide imide enamelled round (flat) wire with long-term use temperature of 180℃ above.

Special enamelled wire includes self-adhesive straight-soldered polyurethane enamelled wire, thermo-adhesive solvent-adhesive polyester enamelled wire, non-magnetic polyurethane enamelled wire freezer-resistant enamelled wire.

2. Wrap the wire

The insulating layer is formed by wrapping the conductive wire core tightly with natural silk, glass wire, insulating paper synthetic resin film. There is also a combination of insulation on the enameled wire then wrapped insulation layer. If the glass wire is wrapped, it must be impregnated with adhesive insulating paint form a combined ground insulation. In addition to a few natural silk wrapping, the general characteristics of wrapping wire are: the insulation layer is thicker than the enamelled wire, it is a combination of insulation. Therefore, it can withstand overvoltage overload load better, is generally used in large medium-sized electrical products. Film wrapped wire has higher insulation performance mechanical strength, which is used in large medium-sized motors high voltage motors.

3. Inorganic insulated winding wire

The insulating layer of inorganic insulated winding wire is composed of inorganic materials, such as ceramic alumina film. It is characterized by high temperature resistance radiation resistance, mainly used in high temperature radiation occasions.

4, special winding wire

Special winding wire is suitable for special occasions has special insulation structure performance. Such as water resistant multi-layer insulation structure submersible motor winding wire, transposition wire high frequency (intermediate frequency) winding wire so on.