How to select the right three phase motor for your machine

As the three-phase asynchronous motor is the leading product of small and medium-sized motors. how can we select the right three phase motor for our machine ?

Compared with conventional motors, high-efficiency motors use energy-quality materials and optimized design, the energy consumption is reduced by about 20% on average, while ultra-efficient engines consume less than 30% less energy than ordinary motors. The price of high-efficiency motors is higher than conventional motors — 15 % to 30% or so. But in general, the investment of high-efficiency motors higher than conventional engines can be recovered within two years, and the company can save electricity for the whole life cycle. Energy efficient motor features: Saving energy and reducing long-term operating costs, it is very suitable for textiles, fans, pumps, compressors; Direct start, or use frequency converter to adjust the asynchronous motor; Rare earth permanent magnet high-efficiency energy-saving motor itself can save more than 15% than an ordinary engine; The motor power factor is close to 1, improving the quality factor of the power grid without adding a power factor compensator; The motor current is small, saving transmission and distribution capacity and extending the overall operating life of the system.

The principle of selecting the motor is that the motor performance meets the requirements of the production machinery, and the engine with a simple structure, low price, reliable operation, and convenient maintenance is preferred. In this respect, the AC motor is superior to the DC motor, and the AC asynchronous motor is excellent to the AC synchronous motor. The squirrel-cage asynchronous motor is superior to the wound-type asynchronous motor. For the continuous operation of the production machinery with no special requirements for starting and braking, the conventional squirrel-cage asynchronous motor should be preferred, which is widely used in machinery, pumps, and fans. Starting and braking are frequent, and production machinery with great starting and braking torque is required, such as bridge cranes, mine hoists, air compressors, irreversible rolling mills, etc., and winding asynchronous electric motor. Where there is no speed regulation requirement, if the speed is constant or the power factor is required to be improved, synchronous motors, such as medium and large capacity pumps, air compressors, elevators, mills, etc., should be used. For production machines with a speed regulation range of 1:3 or higher and continuous stable and smooth speed regulation, it is advisable to use a separately excited DC motor or a squirrel cage asynchronous motor or synchronous motor with variable frequency speed regulation, such as a massive precision machine tool. , planer, rolling mill, hoist, etc. It is required to produce a machine with massive starting torque and soft mechanical characteristics, using series or compound excitation DC motors, such as electric cars, electric cars, massive cranes, etc. Second, the rated power: the rated power of the engine refers to the output power, that is, the shaft power, also known as the capacity, is the motor's iconic parameters. It is often asked how big the engine is, generally not the size of the engine, but the rated power. It is the most important indicator to quantify the ability of the motor to drag load, and it is also the parameter requirement that must be provided when selecting the engine.

When we select the motor, we have to detect the performance of the motor, mainly the following aspects, rated power, rated speed, rated current, efficiency, power factor, locked rotor current, maximum torque, minimum torque, noise.

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Taizhou Dongchun motor Co, ltd. China


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