Single Phase Electric Motor
Manufacturer
In China

Single Phase Electric Motor| The Ultimate FAQ Guide

Introduction

The electric motor is the most effective mechanism that converts energy from electrical to mechanical form. A Single-phase motor performs this job in the most convenient way. Its tremendous benefits allow you to utilize this motor in versatile fields.

Are you familiar with the operating principle, advantage, limitation, etc of a single-phase motor? “Xinnuo motors” is the leading manufacturer of single-phase motors in China.

You will get a sufficiently detailed and straight explanation of different types of single-phase motors and their uses here. So, let’s make a move.

1. What Is A Single Phase Electric Motor?

A single-phase motor is an electric revolving machine. It receives power from a single-phase power supply and then transforms it into mechanical energy. Usually, this type of electric motor is not capable of producing higher torque.

It operates through a single AC voltage and consists of neutral and hot wirings which always experience the same current flow. This motor generates an alternating magnetic field instead of rotating magnetic field intensity.

Figure 1_ Single Phase Electric Motor

2. How Does A Single Phase Electric Motor Work?

A single-phase electric motor is a highly functional electrical to mechanical energy converter device. It starts its operation when a magnetic field is produced and the rotor functions.

One kind of single-phase motor is unable to generate a self-induced magnetic field due to having no starting torque. Some motors contain duel capacitors. These motors have starting torque.

Figure 2_ Single Phase Electric Motor Operation

That’s why it is required to engage an auxiliary winding in this case. This winding is driven through an out-of-phase electrical current. The capacitor motor winding is connected to a capacitor.

This combination acts to initiate a magnetic field that results in the movement of the rotor. Here, the oscillating magnetic field helps to continue its rotation.

In a shaded pole motor, there is a shading coil that acts as an auxiliary winding. It causes a phase delay of the magnetic flux in this motor that renders the necessary revolving magnetic field.

3. What Are The Different Types Of Single Phase Electric Motors?

Different types of single-phase motors are found in the electronics world. Its most prominent types are –

• ML series single-phase capacitor run motor
• MY series single-phase electric motor
• YCL series heavy-duty single-phase induction motor
• YC series single-phase capacitor-start motor
• YL series single-phase dual capacitor motor
• Single-phase induction motors.
• AC series single-phase motor

4. What Are The Applications Of Single Phase Electric Motors?

Single-phase motors have numerous applications in versatile types of equipment. You can use them in offices, residences, commercial zones, etc. But, there is an output power limit in the case of single-phase motors.

Figure 3_ Uses Of Single Phase Electric Motor

  Its most noteworthy applications include-

• Refrigerator
• Compressor
• Home appliances
• Pump
• HVAC
• Drill
• Fan
• Opening and shutting down technology of doors.

5. What Are The Major Components Of A Single Phase Electric Motor?

A Single-phase motor consists of rotor, windings, and stator, cooling fan, centrifugal switch, etc. Among these components, the first three are its principal parts.

Rotor

Rotor takes part in rotating a 1motor. Its shape is cylindrical. So its whole surface consists of lots of slots. There are aluminum-based rotor conductors placed in these slots.

Stator

This is a non-movable part of a single-phase motor. The stator that receives an alternating current,  contains the windings. This AC supply causes Hysteresis and Eddy current loss here.

That’s why stators are constructed with laminated stamping reinforced by silicon steel. The stamping and silicon are worthwhile for reducing Eddy current loss and Hysteresis loss respectively.

Windings

A single-phase motor contains two types of windings. These are called primary and secondary windings. The primary winding is placed in a vertical position concerning the auxiliary winding. This winding is attached to a capacitor that is used in motor starting.

Figure 4_ Single Phase Electric Motor Components

Except for these, bearing, terminal box, power supply, etc are important components of a 1motor.

6. What Are The Differences Between A Three Phase And A Single Phase Electric Motor?

Single-phase and three-phase motors are two different electrical mechanisms to produce mechanical energy for electronic appliances. We are here to explain some distinguishing factors between these two effective motors.

• A single-phase motor contains a single frequency. Here, an alternator having a single winding delivers the source voltage. On the contrary, a three-winding alternator generates AC voltage having a uniform frequency in the case of a three-phase motor.
• Single-phase motors require lesser maintenance compared to three-phase motors.
• Its manufacturing cost is comparatively low.
• A motor operating via single-phase power can produce pulsating torque. But, three-phase motors are capable of generating uniform torque.
• Series operation is easier and more effective for a 1 But, 3 motor’s compatibility with parallel operation is impressive.
• Three-phase industrial motors are usually applied to industrial sectors. On the other hand, 1induction motors have superior uses in residential electronic appliances and commercial types of electronic equipment as well.
• A single-phase motor can’t deliver the same effectiveness and power factor in electronic applications similar to a three-phase system.

Figure 5_ Single Phase VS Three Phase Motor

Inquire us now. We render a one-stop manufacturing service of premium-quality dual capacitor single-phase motors and three-phase synchronous motors.

7. What Are The Advantages Of Using A Single Phase Electric Motor?

A single-phase motor provides significant benefits to electro-mechanical pieces of equipment. Here, the most notable advantages of this motor are explained for your convenience.

• The Single-phase motor does not contain commutators and slip rings. So its construction is easier than many other motors.
• It has simple wiring due to having only two wires.
• This motor doesn’t require enough maintenance and repair.
• Its durability in low-PF (power factor) machinery is impressive. It is resistant to extreme electrical, thermal, and mechanical stresses.
• 1motor’s working life is generally more than years.

Figure 6_ Highly Functional Single Phase Electric Motor

8. How Do You Test A Single Phase Electric Motor?

Testing of a single-phase motor is not a brainstorming task. You just need to follow some basic procedures to verify its performance. Such as:

Primary Inspection

First, inspect the motor’s bearing condition. You have to rotate the motor shaft manually to check this. If the rotation does not seem smooth, you should replace the bearing.

Resistance And Power Supply Test

Next, check if the resistance between the ground and body is less than 0.5 ohms or not. You should use a multimeter to determine the resistance.

Motor Winding Test

There is a start, common, and run terminal in this motor. You need to check the winding resistance between these terminals. Just ensure the highest resistance between the start and run terminals.

Besides, the common-run terminal should have the minimum resistance value and the common-start terminal’s resistance should be between the others.

Figure 7_ Single Phase Electric Motor Testing

Insulation Test

The insulation resistance between the ground and the windings needs to be greater than 1MOhm. That’s why you have to verify this resistance through a tester having 500V voltage. Its deviation causes serious damage to the single-phase motor.

FLA Test

At the running stage, determine the FLA (Full Load Amp) test by using a multimeter. All of these tests can ensure you of faultless performance from your projects driven by single-phase power.

9. How To Reverse A Single Phase Electric Motor?

The reversing process of single-phase motors is different concerning their types and mechanisms. Here, we are going to explain how to reverse split-phase and capacitor-start motors.

Reversing A Capacitor-start Motor

In the beginning, you need to be sure about whether the motor is reversible or not. You can find a label on this motor that indicates the reversibility of a single-phase motor. Then, you have to reverse the starting winding polarity of this motor.

This leads you to the change of rotating magnetic field direction. It is required to alternate the connections of the winding, capacitor, switch on any starting winding end.

Figure 9_ Single Phase Electric Motor Reversing

Reversing A Split-phase Motor

In this case, it is important to verify the resistance and power of the windings. You have to ensure the same resistance in both windings. Again, windings with more than 0.25 HP are not suitable for reversing due to having different turns ratio.

You have an opportunity to switch the direction of motor windings in the case of unequal resistance. If the windings have no binding, you can change the polarity of any winding.

10. How Does The Power Factor Affect The Performance Of A Single Phase Electric Motor?

Power factor indicates the voltage lagging with respect to current. This motor has a maximum PF value of around 0.9 with a full load. It decreases to 0.2 at no-load conditions.

Since the power factor is the proportion of real power to the inductive power, a low PF value is not desirable to any kind of motor. It increases the current flow at a specific load. Excessive current conduction leads to voltage fall.

Again, the power factor influences the system loss reduction in a 1motor. It also improves the load conduction capacity in a circuit. Besides, PF rating affects the design parameters of this motor like an air gap, conductor type, etc.

11. Why Does A Single Phase Electric Motor Have A Low Power Factor?

Several factors are responsible for having a low PF in a single-phase motor. The most considerable causes include-

Inductive load

It causes around 90⁰ lag between voltage and current. This is a significant factor in producing a low PF.

Load Variation

Frequent variation of current load also causes voltage fluctuation. Since a low current load increases the requirement of the stator’s magnetizing current. This property enhances the supply voltage that results in a decreased power factor.

12. Why Does A Split-phase Single Phase Electric Motor Run Slowly?

A split-phase single-phase motor runs slowly due to the rotor’s increased slip rate. The slip rate refers to the variation between the rotor’s revolving rate and the rotating field rate of the synchronous stator.

Its increased value is required for producing the output torque in this motor. That’s why its speed decreases. The following factors cause overload which is also responsible for slowing down the speed of a split-phase motor.

• Faulty bearing in the load.
• Pump’s increased outlet pressure.
• Damage of the run winding.
• Failure of the rotor cage circuit.

13. What Is The Single Phase Electric Motor Winding?

A Single-phase motor contains two windings in its stator. The principal winding’s size is bigger and is composed of thick wires. On the contrary, a smaller winding that is made of thinner wire is the secondary winding.

Both of these windings are connected through a common terminal. The common wires come from this terminal.

Figure 10_ Single Phase Electric Motor Winding

The single-phase power supply is placed between the common and run terminals. But, the capacitor stands amidst the run and start terminals.

14. What Is The Operating Principle Of  Capacitor-start Single Phase Electric Motor?

Capacitor-start single-phase motor requires a capacitor at the starting windings. Capacitor delivers the necessary phase difference in the running and starting winding current.

Here, the starting capacitor rating is very high along with low resistance in the valve of the auxiliary winding. So, its starting torque is around 3-4 times higher than the full-load torque.

Figure 11_ Capacitor-Start Single Phase Electric Motor

Xinnuo motors have been providing ISO-certified heavy-duty single-phase capacitor start induction motors for a long period.  So, contact us immediately to experience the best products.

15. Can A Single Phase Electric Motor Run Without A Capacitor?

Single-phase motors have several types. Among these, capacitor motors can’t run without a capacitor.

These single-phase motors can be classified into three categories based on the use of capacitors. Such as:

Capacitor Start Motor

It requires a capacitor to produce the starting torque. Then it continues its revolving.

Capacitor Run Motor

This motor never uses a capacitor to provide an initial force. But, a capacitor always delivers the required torque to rotate smoothly by connecting to the starting winding in series.

Capacitor Start Capacitor Run Motor

This motor is a combination of the previous two motors. That means a capacitor is used in both starting and running this motor.

16. What Are The Limitations Of Single Phase Electric Motors?

Single-phase motor renders impressive performance in power sectors. Despite having a lot of positive points, it has some negative impacts. Such as:

• It is not supportive of the self-starting process. So, you need to think about an auxiliary starting source for this motor.
• Its power factor is not up to the mark in all applications.
• This motor can’t deliver sufficient torque to run fast.

17. Which Capacitor Is Used In A Single Phase Electric Motor Operation?

Single-phase motors are unable to generate self-starting torque. So, except for shaded-pole and split-phase motors, these motors require a capacitor during starting or running, and sometimes in both cases.

DC capacitors are not applicable for single-phase motors. Usually, run capacitors rating varies from 1.5 to 100uF with a supply voltage of 230V, 250V, 440V, etc. Again, start capacitors are rated for more than 70uF.

18. What Is The Process Of Wiring A Single Phase 230V Motor?

A single-phase motor provides mechanical energy to many types of equipment like fans, air conditioners, etc. You can easily wire a single-phase 230V motor. Usually, power remains in 220V to 240V or 110V-120V forms.

The wiring process for single-voltage and double-voltage motors have the slightest differences. While opening the wiring box, you can find two wires having black color and a green grounding terminal in the case of single-voltage.

First, you have to make a connection between the ground terminal and incoming ground wires. Then it is required to strip and joint these wires through a wire nut. Again, two hot wires are coming from the switch. You have to join them with two loaded wires of this motor.

Figure 12_ Single Phase Electric Motor Wiring

During the wiring of a double-voltage motor, You can follow the instructions given below-

• Unwrap the wiring box and find out the specific wire used in 230V motor wiring.
• Join the ground wire to the green ground terminal.
• Connect the green ground wire to the ground wire for having a terminal connection at the ground.
• Connect both wires found in the wiring box by maintaining the design diagram for the 230 V single-phase motor.
• Then, the remaining segment is similar to the single-voltage motors.

If you face difficulties in wiring, contact a trustworthy manufacturer to handle this issue.

19. What Is The Average Operating Life Of A Single Phase Electric Motor?

The operating life of a single-phase motor depends on several factors. Like power rating, operating temperature, external stresses, chemical contamination, etc. That’s why you can think about a range of working life for this motor.

Usually, its average lifespan is around 6-10 years in the case of a 1-1.5 HP power rating. You can get long-term service through proper maintenance. Even with proper care and choice, it can suffer from multiple environmental issues.

Conclusion

Single-phase motors are supremely connected to our day-to-day life. Xinnuo motors manufacture versatile high-quality single-phase motors with great reliability.

This FAQ guide contains enough information to enlighten you and eliminate your confusion about its applications, wiring, winding, and so on. For any further queries, feel free to get in touch with us. Stay tuned.