In this article we are going to discuss about a starting component known as motor start capacitors, which are found in single-phase and three-phase motors. We will also discuss which type of motor is right for you on the basis of your need. Different Classifications of motors and how test them in terms of horse power, voltage etc.. After reading this article you will be able to differentiate between different kind of motors and you will also be able to select the motor that best suits to your needs. So, read this article till the end because every word in this piece is full of information you would not want to miss.
Deciding what type of motor you need can be a daunting task. There are many different types available today. Before ordering, there are some parameters that need to be addressed. How can this be properly achieved? This article was written to help you decide on the best engine for your application.
Lets Begin.
First of all, you need to know what voltage sources are available for your application. Electric motors can be classified as either alternating current (AC) or direct current (direct current). The alternating current type only operates with an AC voltage, and the DC type operates only with a DC voltage. Some general motors can operate on both AC and DC voltages.
Once you’ve created the power supply you’re using, you’ll need to select the appropriate pattern for your application. AC motors can be divided into single-phase induction, three-phase induction, two-phase multiplexes, and hysteresis synchronization. DC motors can be divided into brushless DC, DC brushless, and stepping types.
Characteristics Of Single Phase and Three Phase Motors
Next, you need to understand the different characteristics of each type in order to properly adapt the motor to its application.
Single-phase induction motors are connected to a single voltage line. An external capacitor is required to run this motor. Different types of single-phase induction motors are distinguished by the method of starting. The four basic types are split phase, start capacitor, permanent split capacitor, and capacitor run/execute capacitor.
Single-phase and three-wire motors use a commutator to cut off the starting winding when the motor reaches 75% of its rated speed. This type has a simple and inexpensive design for commercial use but is characterized by low starting torque and large starting current.
Different Types Of Capacitors In A Motor
The motor start Capacitors are basically a single-phase capacitor motor with a capacitor in series with the starting coil and produces more torque. This motor is more expensive due to switching and capacitor requirements.
Permanently split capacitor motors do not have a start switch. For this type, the capacitor is permanently connected to the starting coil. Since this capacitor is required for continuous use, it does not provide the starting power and therefore usually has a low starting torque. These motors are not recommended for heavy load applications. However, its low starting current, quiet operation, and high life/reliability make it suitable for high cycle rates. It is also the most reliable capacitor motor because it does not have a starter switch. It can also be designed to increase efficiency and power factor at rated loads at the same time.
Capacitors running/capacitor running motors have the motor start capacitors and a running capacitor in the circuit. The starting capacitor will turn off when the operation is completed. This type of motor has high starting, low load current, and high efficiency. The downside is the cost of the motor start capacitors and the switching device. Reliability also affects the consideration of switching mechanisms.
Connecting The Motors
A three-phase alternating current induction motor is wound to a three-phase alternating current. These are the simplest and most durable electric motors available. The motors can be designed for DELTA or WYE connections. This type is designed for continuous use and high starting torque. The engine speed is relatively constant. If three-phase voltage is available, this is the motor of choice.
Two-phase servomotors are so named because they are used in servo systems. They are very sensitive to voltage fluctuations in the control phase. This mode requires two voltages with a 90° phase shift from each other to generate a rotating magnetic field. Servo motors have a high torque-to-inertia ratio and are fast and suitable for speed control applications. Tachometer feedback devices are included with these motors.
Different Types Of Motors
Hysteresis synchronous motors are basically induction motors that operate at synchronous speeds. This is the best option if your application requires faster syncing. These motors can be designed for a single phase or three phases. For single-phase voltage, a capacitor is required. Idling synchronous motors develop what is known as pull-and-pull torque.
- Pull torque is the amount of torque/load the motor can handle when it pulls out of synchronous speed.
- Pull torque is the amount of torque on the output shaft that allows the motor to stay synchronized.
- Pull torque and pull torque are very similar.
These motors have low starting current and vibration. This style of motor is expensive because the rotor assembly is made of hard-to-find cobalt.
The direct current (DC) motors available are brushless DC (BLDC) motors, brush and stepper motors. If only DC voltage is available, you must use one of these motors. Brushless DC motors do not have brushes, so you don’t have to worry about brush wear or sparks. The process requires solid state control and feedback device. These engines feature predictable performance and high starting torque for high speeds. Electronic control makes this style of engine expensive, although smaller packages can achieve greater output.
Unlike brushless motors, brushless DC motors do not require controlled electronics. Brush motors use commutators and brushes to generate a magnetic field. These motors are usually inexpensive, but brush and commutator wear limits reliability and life.
Stepper motors are DC motors that generate incremental steps. If you need to be able to predict the position of the shaft, you can choose a stepper motor. These motors are reliable and low cost. However, its ability to handle large inertial loads is limited.
Final Step
Once you have identified the voltage and frequency sources available for your system, you can determine the number of phases and the type of motor. Second, to help motor design engineers choose the best motor, you need to know the following:
- Output/Horsepower: The designer needs to know the rated speed and torque parameters required for the system.
- Frame size: It is useful for the designer to be aware of mechanical limitations in order to correctly determine the size of the motor.
- Duty Cycle/Rating Time: The relationship between motor running time and idle time is an important criterion when designing a motor isolation system.
- Environmental Conditions: It is always important to inform the engine designer of what type of environment the engine will be seeing. This is important, so the correct enclosure is selected.
As you can see, there are different types of engines. There are also many factors used in the selection. Working with a design engineer will ensure that you have the right engine for your application. This is why it is important to find a manufacturer before finalizing the design of the system.
