Transformers usually use copper wire as the winding material, but there are some cases where aluminum enameled wire is used.

AWG and SWG are two different wire gauge systems used to identify the diameter of the wire. the AWG system is commonly used in North America, while the SWG system is used in places such as the U.K. AWG and SWG are numbered in reverse, i.e., the smaller the AWG number, the larger the diameter of the wire, while the larger the SWG number, the larger the diameter of the wire.


Aluminum enameled wire is slightly less conductive than copper wire because aluminum has about 61% of the electrical conductivity of copper. This means that under the same current conditions, the resistance of aluminum enameled wire will be a little higher than that of copper wire of the same wire diameter. Therefore, the conductivity of aluminum enameled wire needs to be taken into account when designing a transformer to ensure the efficiency and performance of the transformer.

The temperature characteristics of aluminum enameled wire are slightly different from copper wire. The conductive ability of aluminum decreases at high temperatures and the temperature coefficient of aluminum enameled wire is larger. Therefore, the effect of elevated temperatures of aluminum enameled wire on wire resistance and coil performance needs to be considered when designing a transformer.

Aluminum forms an oxide layer when exposed to air, which can negatively affect conductivity. To mitigate the problem of aluminum oxidation, a protective layer is usually applied to the surface of the aluminum enameled wire, such as a layer of aluminum oxide or a special coating material.

The lower cost of aluminum enameled wire compared to copper wire is one of the main advantages of using aluminum enameled wire. In applications where low power or economic considerations are important, the choice of aluminum enameled wire can reduce the manufacturing costs of the transformer.

When selecting and using aluminum enameled wire, applicable codes and standards should be followed to ensure that it meets the relevant electrical safety and performance requirements. These codes and standards may vary depending on the region and application.

Aluminum enameled wire is not commonly used in high power transformers and applications requiring higher electrical conductivity. For most transformer applications, especially in industrial and power applications, copper wire is still widely used because of its better conductivity and thermal stability.

The use of AWG or SWG aluminum enameled wire in transformers requires consideration of wire diameter selection, conductivity, temperature characteristics, and aluminum oxidation issues. Aluminum enameled wire is primarily used in applications where low power or economic considerations are more important and need to be evaluated and decisions made based on specific design requirements and criteria.

Most high power transformers and applications requiring higher conductivity still use copper wire as the preferred winding material. The use of aluminum enameled wire under certain conditions should be evaluated and decided by a professional based on specific application requirements and design criteria.