Why You Should Choose a Single Phase Motor With a High Starting Torque

Single phase motors are electric machines which can be run from a one period power source. They usually use an auxiliary winding to start and do not produce a rotating magnetic field, but rather a pulsating field. Single phase motors develop torque when the rotor is rotated at a different rate than the synchronous speed. Maximum torque is reached when the forward rotating phaser is at exactly 10% slip. High starting torque is desired in most applications as it is the most efficient option in many situations.

Capacitor-start single period induction models are great choices for high torque at starting. These single phase motors use a capacitor in sync with the auxiliary winding to start the machine. Once the machine is up to speed, the capacitor is switched off with a centrifugal switch. This additional starting power allows the auxiliary winding to be formed in a much heavier winding than normal, resulting in a high torque even when the machine is powering heavy loads such as air conditioning compressors.

Capacitor-run induction models are another choice which provides a high starting torque. These machines use two capacitors; one large starting capacitor that provides the high starting torque and a smaller one used during normal operation of the machine. This ensures that the machine runs efficiently and still provides high speeds and power as soon as it is turned on. Two capacitors are usually only put to use in larger machines as they require a more complex construction.

In comparison, resistance split induction models supply only a moderate starting torque and therefore are restricted in the applications they are suitable for. These electric motors use an auxiliary winding of a much smaller size, resulting in lower inducting rate and higher resistance. These simple models can only be used when the load is small and there is little starting drive needed.

Of course, some applications, such as small fans and grinders, do not require a motor with a high starting torque but generally, the higher torque at starting, the greater the load the machine can handle, resulting in a versatile and high performance machine. Single phase motors with high starting torques are typically more expensive than simpler split models, but the difference is worth it in every industrial application. A one phase motor with a high starting torque will deliver the performance you need as soon as the machine is put into operation, ensuring that no time or energy is wasted.