An electric motor converts electrical energy into mechanical energy. It consists of a stator and a rotor, with magnetic fields interacting to produce torque and rotate a shaft. Common types include AC induction motors, DC motors, servo motors, and stepper motors. Electric motors are widely used in industry, appliances, vehicles, and other applications due to their efficiency, reliability and controllability. Proper maintenance and care is required to prevent issues with electric motors.

1. DIFFERENT ELECTRIC MOTOR
OPPERATIONAL DIFFICULTIES AND REMIDES

2. Topic Induction:
 What is electric motor?
 How electric motor function
 Considerations When Choosing Electric
Motors
 Types of Electric Motors
 Applications of Electric Motors
 Benefits of Electric Motors
 Drawbacks of Electric Motors
 Safety Rules of Electric Motors
 Cleaning and Maintenance Routine
 Electric motor problems and solutions
 Advantages of Electric Motors
 Disadvantages of Electric Motors:

3. What Is Electric Motor?
A device that transforms electrical energy into mechanical
energy is an electric motor. The majority of electric motors
produce force in the form of torque supplied on the motor
shaft by interacting the motor magnetic field and electrical
current in a wound wire. Although physically equivalent to an
electrical motor, an electrical generator uses a reverse energy
flow to transform mechanical power into electrical power..
Electric motors can be powered by alternating current (AC)
sources like a power grid, electrical generators, or inverters or
by direct current (DC) sources like batteries or rectifiers.
Concerns such the type of power source, the application, the
construction, and the type of movement output can be used to
categorize electric motors. They can be radially or axially fluxed,
brushless or brushed, three-phase, two-phase, or single-phase,
and liquid- or air-cooled.
Standardized motors provide sufficient mechanical energy for usage in industry. Blowers
and pumps, commercial fans, power tools, home appliances, disk drives, and automobiles
are just a few examples of the applications. Electrical watches contain tiny motors. Electric
motors can be used in reverse as generators to recover power that could otherwise be
wasted as heat and friction in specific applications, such as regenerative braking in traction
motors.

4. PRINCIPLE OF HOW MOTORS WORK

5. STRUCTURAL DESIGN
 An electric motor is all about magnets and
magnetism: A motor uses magnets to create
motion.
 A motor is consist of two magnets.

6. SPINNING ARMATURE IN A MOTOR

7. Electric motor construction The stator, which is permanent, and
the rotor, which is mobile, are the two mechanical parts of an
electric motor. A magnetic circuit is created by two electrical
components—a set of magnets and an armature—one of
which is attached to the stator and the other to the rotor. A
magnetic field is created by field magnets and it travels through
the winding. These could be electromagnets or permanent
magnets. Other motor types have the winding on the rotor and
the field magnet on the stator instead of the other way around.
Electric Motor Bearings
Bearings support the rotor and allow the rotor to spin on
its axis. The motor housing in turn supports the bearings.
Electric Motor Rotor
The rotor is the mobile part that supplies the
mechanical power. The rotor generally holds
conductors which carry current and the stator
magnetic field applies a force on to spin the shaft.
Alternatively, other rotors have permanent magnets,
and conductors are held by the stator. Permanent
magnets give high efficiency over a bigger power range
and working speed.

8. Electric Motor Stator
The stator surrounds the rotor, and generally holds the
field magnets, these are either electromagnets consisting
of wound wire on a ferromagnetic core of iron or
permanent magnets. These produce a magnetic field that
passes through the rotor winding, applying force on the
winding. The stator iron core is made of many thin metallic
sheets which have insulation from each other, known as
laminations.
Electric Motor Armature
The armature comprises wound wire on a
ferromagnetic core. Current flowing through
wire makes the magnetic field exert a
Lorentz force onto it, rotating the rotor, which
supplies the mechanical output. Windings
are wires which are applied in coils,
generally wrapped around a soft, laminated,
iron, ferromagnetic core to produce magnetic
poles when supplied with current.

9. Electric Motor Commutator
A commutator is a rotary electric switch which supplies
alternating or direct current to the rotor. It periodically
reverses the current flow in the rotor winding as the shaft
spins. It comprises a cylinder made of multiple metal
contact sections on the armature. Electrical contacts
named "brushes" consisted of a soft conductor material
like carbon pressed onto the commutator. The brushes
create sliding contacts with consecutive commutator
sections as it spins, offering current onto the rotor.
How an Electric Motor Functions
Electric motors function by changing electrical power
(AC or DC) to mechanical power in order to produce
motion. Force is created within a motor via the
interaction between winding direct (DC) or alternating
(AC) current and a magnetic field. As the current flow
strength rises, so does the magnetic field strength.
With Ohm's law (V = R*I) in mind, voltage should rise
so as to maintain constant current as resistance rises.

10. Considerations When Choosing Electric Motors
Voltage – Is there access to a wall socket or is there a need for a product that can run on batteries. If a wall socket
is available, the voltage standard could be 230VAC or more for industrial use.
Frequency – Motors operate at 60Hz for products working within the United States, but if a product will be utilized
outside of the United States, there is a need to consider a 50Hz option. Speed – Is there a speed range at which the
motor must operate. If adjustable or exact speeds are imminent, there may be a need to improve control to the
motor.
Torque – How much starting torque is needed for an application? Does the torque needed from the motor change
throughout the motor’s period of function? The worst case scenario torque amount of an application must be
considered.
Power – When offering specifications, it should be known if the motor will be running on maximum power
Duty Cycle – It is pertinent to know a motor's duty cycle. If the application will be running continuously such that
the motor reaches full operating temperature or in short spans for the motor to cool down completely between
cycles. Motors that run discontinuously can sometimes use small motors with the same torque and speed, but run
continuously.
Life Cycle – Applications that operate very
discontinuously can at times get on with a short life cycle
and high maintenance needs of Universal and DC motors.
Applications that operate continuously and need to
function for numerous hours without maintenance may
need a brushless DC or an AC motor with a very long
lifespan.

11. Types of Electric Motors
DC Motors
A DC motor is any motor of a type of rotary electrical machine which converts electrical energy from direct current
(DC) into mechanical energy. The most general types depend on the force created by magnetic fields. Almost all
kinds of DC motors have some internal operation, either electronic or electromechanical, to change the current
direction periodically in a part of the motor.

12. 12V Motors
A 12V DC motor is inexpensive and small, but powerful enough to be utilized for various
applications. One property of a 12V DC motor is its operating voltage. When a battery
powers a DC motor, low operating voltage is generally preferred because fewer cells are
needed to achieve the specified voltage. However, at high voltages, electronic devices to
drive a motor are generally more efficient. Although functioning is possible with voltage
as low as 1.5V which goes up to 100, the most usual are the 12V DC motor, 6V DC
motor, and 24V DC motor. Other key characteristics of a 12V DC motor include the
operating torque, speed, current, and power.
Brushless 12V DC motors are the most common type that can
function without using brushes to move electrical current.
Brushed motors, however, may experience issues because of
their more complex design. The majority of these problems
have been resolved by the 12V DC brushless motor's design. A
12V brushless DC motor's primary components are an external
rotor permanent magnet, which can have one, two, or three
coils. Drive electronics and a particular sort of sensor could be
accessories.12V DC brushless motors conduct electricity
through a sensor that is generally referred to as a Hall Effect
sensor rather than using brushes to do it. Although a type of AC
motor may also be referred to as a 12V DC motor,

13. Brushless Motor
A brushless motor is a type of DC motor (BL motor or BLDC motor), also referred to as an electronic
commutated motor (EC or ECM motor). It could also be called a synchronous DC motor. This is a motor utilizing
direct current electric power. It utilizes an electronic controller to turn on DC currents to the windings creating a
magnetic field that successfully rotates in space and the permanent magnet rotor rotates by following. The
controller adjusts the amplitude and phase of the DC current pulse to control the torque and speed of the motor.
This control mechanism is a substitute for the brushes or mechanical commutator utilized in numerous
conventional electric motors.
A brushless DC motor can be made in a manner that is usually
comparable to that of a permanent magnet DC motor, as well
as an asynchronous/induction motor or switching reluctance
motor. They can also use a neodymium magnet and come in
three different configurations: axial (rotor and stator are flat
and parallel), out-runners (rotor surrounds stator), and in-
runners (stator surrounds stator).High speed, high power-to-
weight ratio, nearly instantaneous torque and speed control
(rpm), little maintenance, and great efficiency are the
advantages of brushless motors over brushed motors.
Brushless motors are used in a variety of vehicles, including
model airplanes, automobiles, portable power supplies, and
computer peripherals (printers, disk drives). Brushless motors
have made it possible to replace gearboxes and rubber belts in
modern washing machines with a direct-drive system.

14. Stepper Motors
A stepper motor, also referred to as a stepping motor or step motor, is a
brushless DC motor that divides a full revolution into a number of equivalent
steps. The motor's position may be instructed to change and hold at one of the
equal steps without using any positional sensor for feedback, as long as the
motor is appropriately sized for the use in respect to speed and torque. Brushed
DC motors continuously rotate when direct voltage is put on their terminals. A
stepper motor is known for its characteristic of conversion of a chain of input
pulses square waves to precisely defined increments in the shaft’s rotational
point. Each pulse spins the shaft in a fixed angle.
In the end, stepper motors feature several toothed electromagnets
arranged as a stator surrounding a center rotor, which is an iron
component formed like a gear. An external driving circuit or a
microprocessor provides power to the electromagnets. One
electromagnet is powered, which magnetically pulls the gear teeth in
order to first rotate the shaft. The teeth are somewhat displaced
from the next electromagnet when they are aligned to the first
electromagnet. This indicates that when the subsequent
electromagnet is turned on and the initial electromagnet is turned
off, the gear rotates a little to line up with the subsequent
electromagnet. The process is then carried out once more. Each of
those spins is referred to as a "step," and a full rotation requires an
integer number of steps. In such manner, a motor could be turned by

15. AC Motors
An AC motor is an electric motor powered by an alternating current (AC). The AC motor generally comprises
two primary parts: an outer stator with coils energized by an alternating current to create a spinning magnetic
field. An inner rotor attached to the shaft creates a second spinning magnetic field. The rotor’s magnetic field
could be created by reluctance saliency, permanent magnets, or AC or DC electrical windings.
Less popular, AC linear motors function on similar rules as rotating motors but they have their moving and
stationary components laid out in a straight line set up, creating linear movement instead of rotation.
Synchronous motors and induction motors are the two main
categories of AC motors. The induction or asynchronous motor
is always dependent on slip, which is a very slight speed
difference between the rotor shaft and the stator's rotating
magnetic field. Slip causes rotor current to be induced in the
rotor's AC winding. Because slip (induction) disappears or
becomes irrelevant at synchronous speed, the induction motor
cannot produce torque there. A synchronous motor, in
contrast, uses either salient poles (projecting magnetic poles),
permanent magnets, or an individually energized rotor winding
to function and is not dependent on the induction of slip. At
precisely synchronous speed, the synchronous motor generates
its rated torque. An individually excited rotor winding makes up
the brushless wound-rotor double supplied synchronous motor
system.

16. 1HP Electric Motors
Horsepower or HP is a standard unit utilized to express
the rate of mechanical energy expenditure. A power
level of one HP is roughly equal to 746W or 0.746kW.
While the horsepower, and the kilowatt, can all be
reduced to similar dimensional units, the horsepower is
hardly utilized to express power in any manner besides
mechanical.
2HP Electric Motors
Just like the 1HP electric motor, a 2HP electric motor
works the same way by outputting power at its shaft. In
kilowatts, this power is about 1.49kWIt could either be DC
or AC type (Single phase or three phase). A 2HP electric
motor is used to power boat propellers and industrial
cooling fans or as an induction motor.

17. Single Phase Motors
A single phase motor is a rotary machine powered electrically which can convert
electrical energy into mechanical energy. It works by utilizing a single phase power
source. They have two types of wires: live and neutral. Their power can get up to 3kW
and input voltage varies in unison. They only have one alternating voltage. The circuit
functions with two wires and the AC current that flows across them is always constant. In
many cases these motors are small with a small torque.
However, some single phase motors can
function with connections up to 440V and
have a power of up to 10 HP. They can
only produce an alternating magnetic
field; they cannot produce rotating
magnetic fields, which suggests that a
capacitor is necessary for initial startup.
They are reasonably priced, easy to
maintain, and repair. This kind of motor is
primarily used in small, non-industrial
businesses, households, and retail
establishments. Their most common
applications are HVAC systems for homes
and businesses, drills, air conditioning
systems, and garage door closing and
opening mechanisms.

18. Industrial Motors
Industrial electric motors convert electrical power into
mechanical power. Industrial motors produce either a
rotary or linear force. Although there are types of industrial
motors powered by DC current sources, they are very
often energized by alternating current (AC) supplies like
the power grid or generators.
The main components of an industrial
motor are the rotor (armature), stator, air
gap, winding (coil), and commutator. Types
of motors used in industrial motors include
DC synchronous, AC synchronous, and AC
induction (asynchronous) to name a few.

19. Servo Motors
A servomotor or servo motor is a linear actuator or rotary
actuator which enables precise control of linear or angular
position, acceleration, and velocity. It comprises an
appropriate motor coupled with a sensor for feedback of
position. It also needs a relatively complex controller,
usually a dedicated device designed especially for usage
with servomotors.
Servomotors aren’t an exact class of motors, though
the name servomotor is often used to state a motor
appropriate for usage in a closed-loop control
system. Servomotors are utilized in applications like
CNC machinery, robotics, and automated
manufacturing.

20. A servo motor can use a variety of motor types; the kind chosen is not crucial. Due to their low cost and
simplicity, brushed DC motors (permanent magnet) are used in the most basic configurations. Small
industrial servo motors are typically electronic commutated brushless motors. AC induction motors are
typically used for large industrial servo motors, occasionally with variable frequency drives (VFD) to enable
speed control. Permanent magnet brushless AC motors, which are essentially larger brushless DC motors,
are used for the best performance in small packages.
Applications of Electric Motors
The applications of electric motors primarily include fans, blowers, machine tools, turbines, pumps,
power tools, compressors, alternators, rolling mills, movers, ships, and paper mills. The electric
motor is an important device in various applications like high voltage AC heating, cooling &
ventilating equipment, motor vehicles, and home appliances.
Benefits of Electric Motors
•The main cost of electric motors is less in contrast with fossil fuel engines, however the HP rating of
both are alike.
•Electric motors have moving parts, hence the lifespan of electric motors is longer.
•The capacity of electric motors reaches 30,000 hours when maintained properly.
•Electric motors are very efficient and automatic control allows for automatic stop and start functions.
•Environmental friendly since they do not release pollutants.

21. Drawbacks of Electric Motors
•Big electric motors are difficult to move, and consideration must be done for the exact current and voltage
supply.
•In other cases, costly line expansions are compulsory for isolated zones where electrical power is inaccessible.
•When utilizing a high HP motor and a low load factor, there may be a high expense per hour of working.
Safety Rules of Electric Motors
•Work area must always be kept well-lit and clean.
•All motors have many small components; young children must be kept away from the work area.
•Motors rotate very fast; PPE must always be worn.
•Motor must not be left unattended.
•If a battery is left shorted for long durations of time it might rupture or explode.
•Rated operating voltage must not be exceeded. High voltages might cause overheating and create fires.
•Motors must be operated by qualified personnel.
Cleaning and Maintenance Routine
Motor Lubrication
It’s possible to over lubricate an electric motor, which may lead to internal issues.
However, a motor needs lubrication to work at maximum performance level. Every
electric motor needs a different amount of lubrication. Lubricating a motor very early
or very late may lead to premature tear and wear. Also, manufacturers generally
recommend specific lubricants designed for their electric motor.

22. Bearing Inspection
Motor bearings face most of the tear and wear, so it’s natural to expect issues from them from time to time. To
prevent bearings from wearing out prematurely it must first be assured the motor is aligned appropriately.
Misalignment may significantly stress the bearings. Also, improper lubricants cause bearings to wear out earlier
than they must. One common sign a bearing becomes faulty is an overheating motor.
Reducing or Eliminating Vibrations
Every motor vibrates to some extent, but excess vibration may cause severe damage. The moment a motor
vibrates more than normal, it must be turned off. The cause is usually a mechanical misalignment, a damaged
bearing, or belt tension too high.

23. Rotor and Stator Inspection
The stator and rotor are the important parts of the motor. Any gaps around these parts must be measured and
also with the diameter clearance. Clearance may differ depending on the electric motor and bearings.
Recording Findings
Longevity and wear and tear can’t be monitored if findings are not being recorded. Every time a motor is
inspected and bearings must be replaced or the belt tension adjusted, and so on, note must be taken. In
addition, when lubricant is added to the bearings or motor it must be documented. Upcoming maintenance and
expenses can be better anticipated and planned accordingly.
Electric motor problems and solutions
Low resistance
Low resistance is the most common cause of failure in electric motors. It is also often the
most difficult to overcome. Under conditions such as overheating, corrosion or physical
damage, degradation of the insulation of the internal windings of the motor may occur.
This then causes insufficient isolation between the motor windings or conductors,
leading to short circuits, leakages and eventually motor failure.
Regularly inspect the insulation of the windings for signs of wear and replace before low
resistance leads to failure. If you are unsure, consult an expert.

24. Overheating
Overheating is generally caused by either a high temperature in the operating environment or poor power quality.
It is responsible for around 55% of insulating failures in electric motors. For every 10 degrees Celsius that the
temperature of a motor rises, the insulation life is reduced by half.
To avoid overheating, ensure that electric motors are kept as cool as possible. This can be done by maintaining
as cool an operating environment as possible and regularly checking the temperature of the motor.
Electrical overload
Electrical overload is also commonly referred to as overcurrent. It is caused by an excessive flow of current within
the windings of the motor, which exceeds the design current that the motor is able to carry efficiently and safely.
Overcurrent is often the result of a low supply voltage, which results in the motor drawing in more current in an
attempt to maintain torque. Electrical overload can also be caused by short-circuited conductors, or an excessive
voltage supply.
It is important to install effective overcurrent protection which is able to detect overcurrent and interrupt supply to
protect the motor.

25. Vibration
Vibration can be extremely damaging to electric motors, frequently causing premature failure. It is often caused by
the motor being positioned on an uneven or unstable surface. However, vibration can also be a result of an
underlying issue with the motor, such as misalignment or corrosion.
Electric motors should be regularly inspected for vibration using a motor analyzing tool.
Ensure that electric motors are positioned on a flat and stable surface. If vibration still occurs, check for signs of
wear, as well as misalignment or loose bearings. Consider contacting a specialist if the source of vibration cannot be
easily identified.
Contamination
Electric motors frequently operate in environments where dust, dirt and chemicals are present, which may find their way
inside the motor, leading to contamination and motor failure. These contaminants can dent bearing raceways and balls,
leading to high levels of vibration and wear. They may also block the cooling fan, limiting the motor’s ability to regulate its
temperature and increasing the chances of overheating.
As contamination is one of the leading causes of failure in electric motors, it is essential to prevent it from entering the
motor. Luckily, this is relatively easy.

26. Ensure that work areas, tools and fixtures are kept as clean as possible at all times to help eliminate the
chances of contamination entering the motor. When laying out the workspace, try to position motors
away from applications such as grinding machines which product large quantities of harmful
contamination.
Electric motors are the driving component of a vast range of applications across every industry, and
regular inspection is essential to reduce the risk of premature failure. If you are in doubt about the
condition of your motor, it is always advised to contact a specialist for further investigation.
Advantages of Electric Motors
1. Efficiency
Electric motors are highly efficient in converting electrical energy into mechanical energy. They can operate at
efficiencies above 90%, which means they waste less energy compared to other types of motors.
2. Environmentally Friendly
Electric motors produce no exhaust emissions during operation, which helps reduce air pollution and
greenhouse gas emissions. They contribute to a cleaner and greener environment, especially when powered by
renewable energy sources.
3. Cost Savings
Electric motors generally have lower operating costs compared to internal combustion engines. They require
less maintenance, have fewer moving parts, and do not need regular oil changes. Moreover, electricity is often
cheaper than gasoline or diesel, resulting in long-term cost savings.

27. 4. Instant Torque
Electric motors provide instant torque, meaning they deliver maximum power from the moment they start. This
characteristic makes electric motors well-suited for applications that require quick acceleration or high torque,
such as electric vehicles.
5. Regenerative Braking
Electric motors can be used as generators during deceleration or braking. This allows them to recover and store
energy that would otherwise be wasted as heat in traditional braking systems. Regenerative braking improves
overall energy efficiency and extends the range of electric vehicles.
Disadvantages of Electric Motors:
1. Limited Range
Electric motors rely on batteries for energy storage, and current battery technology has limitations in terms of
energy density. This results in limited driving range for electric vehicles before requiring recharging, which can be
a disadvantage for long-distance travel.
2. Charging Infrastructure
The widespread adoption of electric vehicles requires a robust charging infrastructure. While the charging network
is growing, it is not as extensive as traditional refueling stations. This limitation can pose challenges for long trips
or areas with limited charging options.
3. Initial Cost
Electric motors and associated technologies, such as batteries, can be expensive compared to their internal
combustion engine counterparts. Although the prices are gradually decreasing, the higher upfront cost is a
deterrent for some consumers.

28. 4. Charging Time
Charging an electric vehicle takes longer compared to refueling a conventional vehicle with gasoline or diesel.
While fast-charging stations are becoming more common, the overall charging time can still be a disadvantage
for those who require quick and frequent refueling.
5. Raw Materials and Recycling
Electric motors rely on rare earth elements, such as neodymium, for their magnets. The extraction and
processing of these materials can have environmental impacts. Additionally, the recycling of electric vehicle
batteries is still a developing industry, posing challenges for the disposal of spent batteries.
It's important to note that ongoing advancements in technology and infrastructure are continuously addressing
some of these disadvantages, making electric motors increasingly attractive for various applications.