Difference between Single Phase and Three Phase

Introduction:

Rahul: Abhishek, I want to buy an electric motor. Please suggest some options for it.

Abhishek: Rahul, numerous electric motors are available in the market; you can buy from there, but the best choice is a three-phase electric motor. This is a conversation between two friends; one wants to buy an electric motor, and the other provides an option for him.

From ancient times we witnessed that light is key to development. By keeping this in mind, someone rightly says we can achieve incredible progress with the proper light and electricity. Technological investment is one of humanity's most precious gifts; it helps develop some other things too. Electricity and its related concepts are something that helps humanity in every possible way.

With electrical tools, people effectively perform their work and raise their standard of living. It helps people in numerous ways by making tasks easy to do. By keeping the advancement in every field, the government started supporting the development of several electrical tools, which supported the nation's growth and development. Some of the electrical tools that are necessary for national growth are electric motors, transformers etc.

Today's world is witnessing rapid growth and development, and in this changing world, every sector of the economy has to play a very important role.

Electrical tools help make complex tasks very easy to do; they provide opportunities to develop products that are difficult to develop at any point. Out of the developing concept, the most notable that has shaken the world is the invention of electricity.

Every day the need of people is increasing; to fulfil these needs, firms must develop products quickly and efficiently. And for these, electricity is required. Electrical tools have to produce products very fast by running machines efficiently.

The most notable aspect of the electrical field is the starting of medium and small tools that supports other industries and sectors. Electric motors and transformers are considered the biggest achievement in the economic field. In today's time, everything is directly or indirectly related to the needs of people. Almost all fields currently design or develop their products by keeping consumers in mind. Electricity is not only required for running machines or tools, but at the same time, it offers jobs to a large chunk of the population. Numerous companies are running to provide and generate electricity that offers many people jobs. In this article, we will discuss the phases of electric motors and their differences.

What Constitutes Electric Motor as Greatest Achievements:

Electricity is considered one of the greatest achievements of humanity. Without electricity, nothing is possible because it supports all sectors of the economy. Benjamin Franklin and Michael Faraday are considered the fathers of electricity. They initially developed electricity for study, but soon after advancement in it, it is regarded as one of the most notable developments of modern times.

Michael Faraday discovered the electric motors. Electric motors in today's times are used for a variety of purposes. Small to large electric machines require electric motors to run or operate efficiently. Electric motors are the backbone of the agriculture and industrial sector. Both sectors required electricity to fulfil their task. For example, in agriculture, electric motors are required for irrigation purposes. In contrast, Industries required electric motors to run machines. So every sector requires electricity; most importantly, electric motors are the backbone of economic growth and development.

What are Electric Motors?

Electric motors are the electrical machine that Michael Faraday discovered. It is regarded as one of the greatest achievements of scientists in the electrical field. It is used to convert electrical energy into mechanical energy. Most electric motors interact with the motor's magnetic field and the electric current in a wire. It generates force through torque applied on the motor's shaft. Today, every sector of the economy requires electric motors, most importantly agriculture and the industrial sector. It forms the backbone of several industries; it helps the industries produce goods.

Phase in Electricity:

There are two ways in which current flows in electricity: Direct Current and Alternating Current. The major difference between Direct Current and Alternating Current is the direction in which current flow occurs. In Direct Current, the direction flow is unidirectional, or the current flows in one direction. And in alternating current, the current can be flown in both directions, or the current can be reversed in its direction. The Alternating Current majorly swings between zero and its peak value. And the current in alternating form constantly varies to form a sinusoidal waveform. The two notable things in single are frequency and phase. The signal frequency is defined as the number of cycles per second.

On the other hand, phase is the point or position during the waveform. Phase is always mentioned in degrees, ° or radians. When we talk about the Phases in the electrical system, it is considered several distinct sinusoidal AC waveforms, which have the same frequency but have a common phase difference.

Depending on the region, an alternating current is used to supply a 50/60 Hz frequency signal. The type of electrical system decides the phase of the system. The most notable aspect of a single Phase current supply is its power supply with only one AC wave. On the other hand, the three-phase supply has three equally separated waveforms with the same frequency. The 360° phase cycle is divided into three equal parts, meaning the phase difference between any two phases is 120°.

What is a Single-Phase Power Supply?

A single Phase, power supply system is a type of alternating current under which all the voltages vary in the same sinusoidal pattern. It is delivered using two wires: the power and the neutral wires. The power wire is also known as hot, live, line, or phase wire. The power flows between the neutral wire and the phase wire with the help of load. The role of the Phase wire is to supply the power to the load; on the other hand, the neutral wire is used to provide a return path for the current flowing through the load. Sometimes, it is also called the split phase.

Under a single phase, the voltage mainly fluctuates between zero and peak points. In a single phase, the maximum peak point occurs at 90°, while the minimum peak occurs at 270°. Sometimes voltage goes to zero point also. Because of this reason, single-phase power is not efficient compared to the three phases, which is why it is not used to power high-rated machines. Single-phase electric systems are mostly used for appliances below 1000 watts. A single phase's basic requirement is two wires; they are quite simple. Also, the costs of designing are very cheap. But it is not considered a reliable option concerning three-phase because a power failure can occur due to a fault in the line. Single Phase power supply system has a wide range of applications, from every household item to offices and small equipment in industries. It is efficient for powering small appliances below 1000W.

The cavities in single phase supply are that it cannot run motors independently. This is because it cannot generate a rotating magnetic field (RMF) in an induction motor, and it requires extra motor starting circuitry for proper operation.

What is a Three-Phase Power Supply?

Under the three-phase electric system, the phase power contains three voltages 120° apart from individual sinusoidal waveforms. It uses three different types of individual conductors with different colour-coded wires for individual phases. The voltage and current between any two power conductors are 120° phase apart. Three phase power supply is also known as the Poly-phase power system. The three power supply phases have different advantages over single-phase electric systems. They are used for powering a load connected in either of the two configurations, i.e. delta configuration and Star or Wye configuration. The basic difference between these two configuration types is that there is no neutral cable in the delta configuration. It only uses 3 phase or power cables to supply power to the load.

Difference between Single and Three Phase Power Supplies:

In the above paragraphs, we already discussed the definition of Phases and their types. These two phases are the most used electric system in electricity. Both are essential for supplying power to different electrical sources.

Let us now examine the major differences between single-phase and three-phase power supplies.

Types of Wires used:

The major difference between Single Phase and Three Phase power supplies is the types of wire used. In a single-phase electrical system, power is mainly supplied using two wires: a Phase and a neutral wire. While in Three Phase electric system, power is supplied with the help of three wires. And if a neutral wire is also used, it may be converted into a four-wire electric system.

Voltage:

The other major difference is the type of voltage used to supply power. In a single-phase electric system, the required voltage is 230V. With increasing Phases, the amount of voltage also increases. In a three-phase electric system, the required voltage is 415V.

Efficiency:

A single-phase electric system requires more wires than a three-phase electrical system to deliver the same amount of power. When we discussed the efficiency of both phases, the three-phase electric system offers more efficiency than the single-phase electric system. Three-phase electric systems have a higher frequency than single-phase electric systems. The capability of transferring power is also different in both Phases. Three-phase electric systems have a higher capability of power transfer.

This is because the number of wires in a single-phase electric system is two, whereas, in a three-phase electric system, there are four wires if neutral is included. Due to that complexity, transfer power is less.

Some other major differences are -

1. A single Phase electric system requires two conductors for power supply. On the other hand, the Three Phase electric system requires three conductors for supplying power.
2. The two wires used in the single-phase electric system are Phase and Neutral. The wires used in the Three Phase electric system are known as Phases.
3. Due to single phase wire, only one AC signal, mainly a Sinusoidal Wave. On the other hand, three wires in three phase supply carry AC signals of their own, and the three signals are 120° apart.
4. Another important point that creates differences between these two phases is the peak and dip in power supply. As the Single Phase power supply system contains two wires, the power delivery could be more consistent due to peaks and dips in voltage. In the case of a three-phase electric system, three conductors are involved in the power supply at 120°, due to which the power supply is steady and constant. Peaks and dips in three-phase electric systems compensate each other during power supply.
5. The supply voltage in a single-phase power supply is ≈ 230V. On the other hand, the power supply in the three-phase electric system is ≈415V.
6. When we talked about efficiency between these two phases, the three phases electric system is more efficient and effective than single phase electric system for the same amount of power delivery. The reason behind efficiency is that three-phase electric systems deliver three times more power than a single-phase power supply with just one additional wire.
7. Level of operation between these two phases is also different. Single Phase electric system used to supply power for residential and domestic purposes. On the other hand, the Three Phase electric system supplies power to large commercial centres and industries. Single Phase electric systems are generally used in small loads like lighting and heating. And Three Phase electric systems are installed in big Industries.
8. A single-phase electric system must have a Neutral wire, otherwise a phase wire. But in a three-phase electric system, the neutral wire is optional.
9. The chances of faults occurring are maximum in Single Phase electric system because it has only one available wire. The chances of faults are low in the Three Phase electric system. If any fault occurs in any wire, the remaining phase(s) will continue to deliver power in Three-Phase Power Supply. So, the chance of fault is less.

Conclusion:

Both types of phases are necessary as they supply electric power for different purposes.