Electric motors of various designs differ from each other in the way they generate a rotating magnetic field. The circuit for switching on the motor, the type of current and the number of phases for its power supply, as well as its area of application, depend on this.
Instructions
Step 1
The collector DC motor has two leads. If you apply a rated constant voltage to it at a rated load on the shaft, it will start to rotate at the speed indicated in the passport. To reduce it, lower the supply voltage (but not too much, otherwise it will stop and may burn out). To change the speed of such a motor, reverse the polarity of the supply voltage. Powerful motors of this type cannot be switched on without load in order to avoid self-destruction by increased speed.
Step 2
The universal collector motor can operate on both DC and AC voltage. The dependence of its rotational speed on the supply voltage is not linear, as in the engine discussed above, but is expressed in a complex curve. When AC voltage is applied, it will rotate at the same frequency as when applied at the same load, DC voltage equal to the AC rms value. When supplying with direct current, the polarity reversal at the input will not change the direction of rotation of the motor. It can be reversed by changing the polarity of connection of either only the stator, or only the collector-brush assembly. Such a motor is even more sensitive to overloads and no-load switching than the previous one.
Step 3
An asynchronous three-phase electric motor can only be supplied with alternating current. On its case, two voltage values are indicated through a fraction: the smaller one for turning on with a triangle, and the larger one for turning on with a star. Ground the motor housing, connect it to a three-phase network, connecting the windings with a delta or star, depending on the value of the mains voltage, and do not connect zero anywhere. To reverse such a motor, turn it off, let it come to a complete stop, reverse any two phases, and turn it back on.
Step 4
Single-phase asynchronous motors are divided into single-winding and double-winding. In the former, the direction of rotation is determined by the design of the magnetic shunt and can be changed to can. Such a motor has one winding, for which it is enough to connect to the network with the voltage and frequency indicated on the nameplate. In a two-winding motor, connect a winding with a high resistance to the network directly, and with a smaller one through a capacitor (necessarily paper), the capacity and rated voltage of which are indicated on the motor. To reverse it, you must swap the terminals of either of the two windings.
