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Comparison of actual measurement of enameled aluminum wire and enameled copper wire used in motors

Update:27-10-2020
Summary:The silver-white coil on the left side of the figure below is a single-phase induction motor using enameled aluminum wire, and the right side is a tra
The silver-white coil on the left side of the figure below is a single-phase induction motor using enameled aluminum wire, and the right side is a traditional enameled copper wire motor. The test method is to compare the parameters of the motor performance standard with enameled aluminum wire, only changing the enameled aluminum wire The wire diameter of the copper wire is measured by measuring how much the wire diameter of the enameled copper wire has to be reduced before it has the same motor specifications as the enameled aluminum wire.
The biggest difference between enameled aluminum wire and enameled copper wire for single-phase induction motors is also caused by the poor conductivity of aluminum, so the wire diameter of enameled copper wire has to be reduced to 0.12 The same motor specifications as enameled aluminum wire can be reached by about mm. On the contrary, if the single-phase induction motor that originally used enameled copper wire is changed to enameled aluminum wire, the wire diameter must be somewhat larger. To increase, it can reach the specifications required by the original motor. Therefore, the motor will need more space to accommodate the increased wire diameter, but this more space is often the most difficult to provide among the motors.
In order to solve the problem of increasing wire diameter space when using enameled aluminum wire, it is better to replace it with a motor that does not need to consider the slot full rate. A few motors have such special values, among which the stator field coils of general motors This is an example of this. As shown in the figure below, the test conducted this time is to measure the effect of changing the sub-coil directly to enameled aluminum wire to enameled copper wire and the characteristics of the motor with the same specification of wire diameter and number of turns.
From the comparison of the above enameled copper wire and enameled aluminum wire, it is obvious that the efficiency, torque, speed and output power are greatly reduced, so simply use the same wire diameter and number of turns to replace it. If it is not feasible, it is necessary to re-plan and design a new wire diameter and number of turns to achieve the same output specifications.
The use of enameled aluminum wire as a replacement material for enameled copper wire failed and was not adopted in the use of electric motors. The difference in use between aluminum and copper, wire tension and spot weldability were the main rejected the reason.
The failure of the development of enameled aluminum wire did not hinder the development of replacing copper with aluminum. Instead, copper-clad aluminum, which is more convenient to use, was introduced. The outer ring uses 15% copper to cover the inner 85% aluminum. Such a composite approach will greatly improve the applicability, and the acceptance and possibility of substitution will increase.
Due to the addition of copper, the performance of the wire can be improved, but the composition of aluminum is still as high as 85%, and the decrease in conductivity is still an unavoidable problem. It is also necessary to increase the wire diameter to solve the difference in material. It must be used in a structure with sufficient space Among the motors, the technology of using enameled copper-clad aluminum wire has been very mature. Considering the cost and product competitive advantages, the number of manufacturers used has increased significantly, and there is a trend of full replacement.
Observed from the motor characteristic measurement data, in fact, there is still a small drop in the number of specifications, but it is very close, the difference is about 2%, so it is acceptable in practical applications.
Shaded pole motor is a kind of single-phase induction motor. It is a motor with simple structure but low output power. Its working efficiency is not good. It is suitable for occasional action occasions, such as vending machines. The appearance is shown in the figure below. It shows that the black part is the motor coil, which is simple to wind and has no space limitation. Therefore, enameled copper-clad aluminum wire can also be used to reduce production costs.
In conclusion
Today, when raw materials continue to rise, the price of copper is an unsolvable problem faced by electric motor factories. This alternative material of copper-clad aluminum is one of the solutions. Copper-clad aluminum wire has essential defects in any case, and it is difficult to compare performance with copper wire. However, as long as it is used properly, the difference can be greatly reduced. It still has excellent market value and can bring new products to the motor. The cost and additional lightweight competitive advantage.