Notesale: Turn your study into money

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A motor is an equipment utilized for the conversion of electrical energy to mechanical energy to act
upon a mechanical load
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Motors are used to turn mechanical devices such as fans, conveyor belts etc
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The centrifugal pump is the mechanical device the motor runs
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Such properties may
be the power drawn from the line, efficiency, speed, the amount of current etc
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Proper and necessary motor selection must be done to
efficiently match the motor to the requirements of the load
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Hence, knowing the load profile (speed range, torque and power) is essential
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In listing, they are namely:

I
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Adapted from 5 Most
Common Motor Load Types by Electrical Engineering Portal (2015)
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com/5-most-common-motor-load-types
Constant torque loads need fixed or invariable amount of torque at both high and low speeds
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Additionally, due to horsepower being directly
proportional to speed, with an increase in speed follows an increase in horsepower
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With this type of load, the torque of the load will
remain fairly fixed and the horsepower will change linearly with speed
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To exemplify, if the speed increases by 75%, the power required to keep the
operation running would also increase by 75% with the condition where the torque is fixed
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Some constant torque load applications are:
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II
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Adapted from 5 Most
Common Motor Load Types by Electrical Engineering Portal (2015)
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com/5-most-common-motor-load-types

This is the most common load type
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The torque of the load is directly proportional to the square of the speed while the load
power is directly proportional to the cube of the speed
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Conversely, such loads may require increased
torque when driven at speeds greater than the base speed of the load
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In exemplifying, when the speed of a variable torque
load is reduced by 50%, the torque is reduced to 25%
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5% of that required to drive the load at full speed
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Centrifugal Compressor
Centrifugal Blower
Centrifugal Fans
Agitator

Constant Power

Figure 3 – Typical torque and power curves in a constant power application
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Retrieved from https://electricalengineering-portal
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In other words, constant horsepower despite any changes in speed
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A decrease in operating speed causes an increase
in torque so that the horsepower would remain constant
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Power is constant so there will rarely be energy savings when the
speed is reduced
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Constant Power/Torque

Figure 4 – Typical torque and power curves in a constant power/torque application
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Retrieved from
https://electrical-engineering-portal
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As the speed increases, the torque is constant with the power linearly increasing
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This load type is a
result of dimensioning a system according to the need for certain power at high speed
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Constant power/torque load applications are typically used in the Paper Industry
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V
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Adapted from 5
Most Common Motor Load Types by Electrical Engineering Portal (2015)
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com/5-most-common-motor-load-types
This load type is characterized by high torque at relatively low frequencies
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As such, initial torque needed to move a stationary load is
called the breakaway torque
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The motor must
have enough breakaway torque to start the load
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These loads have high inertia and therefore may take a significant
period of time to accelerate or decelerate
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d
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Retrieved from:
https://avsld
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sg/3-types-of-loads/

Edvard (2015, May 20)
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Retrieved from:
https://electrical-engineering-portal
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d
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Retrieved from:
https://neutrium
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d
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Retrieved from:
https://www
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co
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Motor Driven Load
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openelectrical
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php?title=Motor_Driven_Load

Tpub (n
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Neets Module 05-Introduction to Generators and Motors
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tpub
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htm

Tynan, K
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What is Motor Load? Retrieved from:
https://www
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com/what-is-motor-load

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