The difference between a three-phase electric motor and a single-phase one; In this article, we intend to introduce you to the differences between single-phase electric motors and three-phase electric motors, so stay with us.
At first, it is necessary to get acquainted with the differences between electric motors, and then we will explain each method: Three-phase electric motors have more starting cracks. Single-phase electric motors are limited in power and can produce up to 5 horsepower. Three-phase electric motors have less current draw than single-phase electric motors.
🔰Generally, three-phase electric motors have less vibration than single-phase electric motors. To familiarize you more with the features of single-phase and three-phase electric motors, and at first, we will introduce you to the features of each, and finally, we will conclude the differences in each.
Characteristic of single-phase electric motor
1- In single-phase electric motors, two coils are used, one of which is the main coil and the other is the starter coil, which places the stator in the electric motor at an angle of 90 degrees relative to the other. to give The role of the starter coil is to create a rotating electric field, which is necessary to start the electric motor. After starting the engine, the starter coil can be removed from the circuit.
2- Single-phase electric motors have different types, which include electric motors with broken phase, capacitor, slotted pole, repulsive, universal, synchronous. 3- In electric motors with broken phase winding The main coil with a large number of turns and diameter and a secondary coil with a small number of turns and diameter are selected, and after starting, the starting coil is removed from the circuit by means of a centrifugal switch. This type of electric motors have a small starting torque.
4- There is a capacitor in series capacitor electric motors that have a secondary coil, and these types of electric motors are made into three categories, which include temporary capacitors, permanent capacitors, permanent capacitors, and temporary capacitors.
Motor With a slotted pole, no secondary winding is made, instead there is a copper or aluminum shorting ring on the stator. This motor is made up to 120 watts.
5- Universal electric motor has a coiled rotor and can work with alternating and direct electricity. These electric motors have one number of brushes and one number of collector blades. The speed of this type of electric motors reaches twenty thousand revolutions per minute. And it is used in household appliances such as vacuum cleaners, meat grinders, and grinders. 6- To change the direction of rotation of single-phase electric motors, the direction of current in the main coil should be changed relative to the secondary coil or the secondary coil relative to the main coil.
7- From the relationship 60F/2P, it is possible to calculate the synchronous speed in induction motors, where F is the frequency and 2p is the number of pole pairs. The centrifugal switch operates at 75% of the rated speed and takes the secondary winding out of the circuit.
Characteristics of three-phase electric motor
The heads of each coil in the IEC standard are marked with the letters U1, V1, W1 and the ends of each coil are marked with the letters U2, V2, W2.
The heads of each coil in the VDE standard are marked with the letters U, V, W and the end of each coil are marked with letters X, Y, Z.
1- The three-phase electric motor can be started in two ways: star or delta, which depends on the type of electric motor. It is connected to U1, V1, W1 and phases L1, L2, and L3, respectively. 3- In triangular connection, L1 phase to U1, W2 and L2 phase to V1, U2 and phase L3 are connected to two ends of W1 and V2. 4- The voltage reached to each motor coil in delta mode is 1.7 times that of star mode. In other words, the voltage received to each winding of the motor in star mode is 1.7 times that of delta mode.
5- The current passing through each coil in delta mode is 1.7 times that of star mode. In other words, the current passing through each coil in star mode is 1.7 times that of delta mode.
6- The power of the electric motor in delta mode is 3 times the power of the same electric motor in star mode, so it can be concluded that in places where you need higher power, use delta mode, but you should also pay attention to the line voltage, which will be discussed later. Let's discuss. 7- There is a word similar to Y 380 on the nameplate of three-phase electric motors, which indicates the voltage that can be connected in star mode. In this example, the electric motor in delta mode should be connected to a grid whose line voltage is 220 volts, and it can be star connected to a grid whose line voltage is 380 volts. 8- Three-phase motor with 3 wires It is a screw that has a 120 electrical degree difference in place from each other on the stator.
At the end, it is necessary to say that you should pay attention to these differences before buying your electric motor.