SIMO Motor technical documentation: From the nameplate and manual of wound-rotor asynchronous motors, aluminum-core wound-rotor asynchronous motors feature more “l” or “a” characters in their model numbers than copper-core counterparts. Moreover, aluminum-core motors of the same rating are lighter but slightly larger in volume than copper-core ones. Counterfeit products may not be identifiable by surface inspection alone. The conductor core colors differ between wound-rotor asynchronous motors. Note that some conductors use aluminum-clad copper. Thus, if you cut a wire, the white interior material indicates aluminum. If disassembly is possible, try cutting a wire at a non-critical location; after inspection, reseal it with high-temperature tape. When disassembly is impossible, compare coil resistance—aluminum-core coils exhibit slightly higher resistance than copper-core ones.

　　1. Copper exhibits superior electrical conductivity to aluminum: copper wire carries 6 A per mm², whereas aluminum wire carries only 5 A per mm²; thus, aluminum-wound asynchronous motors tend to overheat during prolonged operation. Although temperature typically remains below 90 °C under normal conditions—and such cases rarely pose issues—the overall performance of aluminum-wound asynchronous motors is less stable than that of copper-wound models. Aluminum-core asynchronous motors deliver significantly lower power output and reduced current-carrying capacity, resulting in greater heat generation. Generally, aluminum-wire motors produce approximately 20% less power than equivalent copper-wire motors.

　　2. Pure-copper-wound asynchronous motors naturally offer superior durability. Aluminum’s higher resistivity leads to greater heat generation during operation, making wound-rotor asynchronous motors more prone to burnout. Furthermore, aluminum and copper cannot be reliably welded together, causing connection points (e.g., power leads) to overheat and fail. Consequently, the mechanical service life of aluminum-wound asynchronous motor pumps is substantially shorter than that of pure-copper-wound asynchronous motor pumps.

　　3. Pure-copper-wound asynchronous motors consume less electricity. In electrical circuits, component resistance is directly proportional to heat generation: higher resistance results in greater heating.

　　4. Pure-copper-core wound asynchronous motors generate less noise. A 3 dB increase in sound pressure level corresponds to a doubling of acoustic energy. Aluminum-wound asynchronous motors produce approximately 7 dB more noise than copper-wound models—meaning their noise energy exceeds that of copper-wound motors by over two times. The overall noise level of pure-copper-wound wound asynchronous motor pumps is merely 58 dB(A).

　　5. Pure-copper-wound asynchronous motorsSIMO Motorexhibit relatively higher durability. Aluminum’s higher resistivity causes elevated operating temperatures, increasing susceptibility to burnout in wound asynchronous motors.

　　6. For example, the resistivity of copper wire in vibrating-wound asynchronous motors is 0.017 Ω·mm²/m, while that of aluminum wire in vibrating-wound asynchronous motors is 0.028 Ω·mm²/m. The cross-sectional area ratio for equivalent copper-to-aluminum wire substitution is 0.79:1; thus, a 6 mm² copper wire corresponds to a 10 mm² aluminum wire. Aluminum wire has a larger diameter than copper wire; consequently, within the same stator slot, aluminum wire occupies more space, and current density per unit area differs: copper wire can carry approximately 5–8 A per mm²—hence, amperes

　　7. Aluminum wire is lighter and comparatively less expensive, yet possesses inferior mechanical strength. Aluminum wire termination points oxidize readily, and oxidation raises contact temperature, leading to poor connections—making them frequent sites of failure and breakage. Additionally, aluminum wire is difficult to weld due to its low melting point and strength, and it oxidizes easily, resulting in significant temperature rise and energy losses.

　　The above content—provided by Xiao Pian—covers methods for determining whether a wound-rotor asynchronous motor uses copper or aluminum windings. Customers requiring further details are welcome to call us for consultation. You may also continue monitoring our official website.