TECHNOLOGICAL INSTITUTE OF THE PHILIPPINES

938 Aurora Blvd., Cubao, Quezon City

ELECTRICAL ENGINERING PROGRAM

In partial fulfilment of the Requirement for the Degree of Bachelor of Science in Electrical Engineering
Program and for the Completion of the course (AC Machinery / EE 403) through the Design of Experiment
entitled: “Design of Experiment to Evaluate 3 Phase AC Motor with 1.5 Horsepower”

Submitted by:

Billones, Elden Kyle B.

Pablico, Christian J.
Reñido, Kim Jeremiah F.
Salvador, Mark Kenneth S.
Valdez, Ryan M.

Submitted to:

Engr. Alvin T. Dela Cruz

Instructor

Engr. Ferdinand D. Milan

Program Chair

March 9, 2018

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 TABLE OF CONTENTS

Title of the Design Experiment 1

Table of Contents 2

Chapter I – Background, Purpose and Significance

Background of the Design of Experiment 3

Statement of Purpose 6

General Purpose 6

Specific Purpose 6

Chapter II – Methodology

Discussion of Methodology 6

Process Flow Diagram 7

Electrical Diagram 9

Chapter III – Actual Testing

Step by Step Procedure 10

Materials and Equipment 11

Actual Experiment 16

Schematic Diagram 17

Chapter IV – Presentation of Data and Test Results

Data and Results 18

Computation of Data 22

Statistical Analysis 27

Chapter V – Conclusion and Synthesis 35

Bibliography/References 37

Curriculum Vitae 38
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I. BACKGROUND OF DESIGN OF EXPERIMENT

3 Phase AC Induction Motor

An induction motor or asynchronous motor is an AC electric motor in which the electric current in

the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the

stator winding. An induction motor can therefore be made without electrical connections to the rotor. An

induction motor's rotor can be either wound type or squirrel-cage type.

In both induction and synchronous motors, the AC power supplied to the motor's stator creates a magnetic

field that rotates in synchronism with the AC oscillations. Whereas a synchronous motor's rotor turns at the

same rate as the stator field, an induction motor's rotor rotates at a somewhat slower speed than the stator

field. The induction motor stator's magnetic field is therefore changing or rotating relative to the rotor. This

induces an opposing current in the induction motor's rotor, in effect the motor's secondary winding, when

the latter is short-circuited or closed through an external impedance. The rotating magnetic flux induces

currents in the windings of the rotor; in a manner similar to currents induced in a transformer's secondary

winding(s).

Figure 1 – Inherent slip - unequal rotation Figure 2 – Three-phase power supply provides a

frequency of stator field and the rotor. rotating magnetic field in an induction motor.

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Construction

An induction motor consists essentially of two main parts which is the stator and the rotor. The

stator of an induction motor is, in principle, the same as that of a synchronous motor or generator. It is

made up of a number of stampings, which are slotted to receive the windings. The stator carries a 3-phase

winding and is fed from a 3-phase supply. It is wound for a definite number of poles, the exact number of

poles being determined by the requirements of speed. Greater the number of poles, lesser the speed and

vice versa.

Figure 2 – Unwound stator with semi-closed slots and completely wound stator for an induction motor.

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II. STATEMENT OF THE PURPOSE

The purpose of this design experiment is to familiarize the parts, how to re-wind magnetic copper wires and

to identify the function and how to wind magnetic

Main objective:

To repair and run a 3 Phase AC Induction Motor with 1.5 horsepower.

Secondary objective:

1. To evaluate the repaired motor.

III. DISCUSSION OF METHODOLOGY

Strategies and Methods:

1. Determine the title of “Design of Experiment”.

2. Discussion with the group members on what technique is going to use in the experiment.

3. Determine the problem to be solved based on the title of the assigned design of experiment.

4. Propose a solution for the problem

5. Task distribution among the group members.

6. Research about the assigned title.

7. Test the said motor, and record the needed data gathered during the test.

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Process flow diagram:

Start

 Design of Experiment to
Evaluate 3 Phase AC Motor
Design Title with 1.5 Horsepower

 1.5 HP SCIM unit

Needed Materials

 Use of electrical engineering

Application of knowledge in creating the
Concepts design of the SCIM

 Connect the necessary

Creating the components to the induction
circuit motor
 Conducting tests on the SCIM

Gathering of Data  Collecting all the important data

we got from testing the SCIM

Findings and  Solve unknowns using data

gathered along with the formulas.
Conclusion
 Create a conclusion

End

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 The operational flowchart shows how each step must be taken in the process of performing this

design experiment. First, we must know what type of AC induction motor will be using, along with the

needed materials needed. Next, we should know the technique used for the connection recommended for

the motor. Next, we measure the data that will be important for the test of induction motor and the

knowledge we gained in this EE 403 course. Next, we state our conclusion in regards to our findings in this

design of experiment. Lastly, we will compile all the papers and we will prepare for the project submission.

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Electrical Diagram:

Figure 3 – Exploded view of the squirrel cage motor showing the stator, rotor, end-bells, cooling fan, ball

bearings and terminal box. The fan blows air over the stator frame, which is ribbed to improve heat transfer.

Figure 4 – Schematic diagram of Squirrel Cage Induction Motor.

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Step by Step Procedure:

1. Make sure all the materials needed are complete and working.

2. Measure the dimensions of the induction motor.

3. Compute for the other values using the measured dimensions of the Squirrel Cage Induction

Motor.

4. Connect the 3-phase induction motor to the 3-phase plug to the circuit breaker

Figure 5 – Actual set-up on the 3-phase Induction Motor 1.5 Horsepower.

5. Turn on the circuit breaker, then turn on the induction motor.

6. When the induction motor is running get the RPM of it by using digital tachometer, and the current

by using clamp meter.

7. Record all the gathered data.

8. Turn off the induction motor

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IV. DISCUSSION ON HOW THE TEAM OBTAINED THE TEST RESULTS

Needed Laboratory Materials:

Name Picture Specification

 Three-Phase
 1.5 Horsepower (1119 Watts)
Induction Motor
 50/60 hertz
 Squirrel Cage

 240 Volts
Circuit Breaker  40 Amperes
 3 Phase

 3.4 A
Magnetic Contactor
 600 V (Maximum Voltage)
and Relay
 3 phase

 3 Phase
Plug
 220 volts

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 Clamp meter  DC Voltage 400/600 (V)
 AC Voltage 400/600(V)

Connecting Wires  Stranded wire with fuse

 Tondaj DT-6234B Digital

Digital Tachometer
Tachometer 2.5--99,999RPM

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Actual Representation:

Figure 6 – Rotor Design.

Figure 7 – Rotor Design and Squirrel Cage Induction Motor Casing.

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Figure 8 – Three Phase AC Induction Motor with 1.5 Horsepower.

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ACTUAL PICTURE OF THE MEMBERS PERFORMING THE EXPERIMENT:

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SCHEMATIC DIAGRAM

Figure 14 - Connection of Motor and Three Phase Source

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V. PRESENTATION OF DATA AND TEST RESULTS

Figure 15 – 1.5 Horsepower Three Phase Induction Motor Nameplate.

Current
Voltage W (kW) Power Power Factor Torque
Trial (A) Speed
(L-L) Total (N*m)
I1 I3 W’ W” p.f.1 p.f.2
1
2
3
4
5

Calculated Data and Tabulated Test Results

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 Design Sheet for a Squirrel Cage Induction Motor

Specifications: 1.5 hp, 3-phase induction motor, 220

Item No. Symbol: Numerical Values:
volts; 60 cycles, 1787 rpm, (induction)

1. Number of Poles p 4

2. Volts per phase (delta connection) E 220 V

3. Estimated full-load power factor cos θ 0.78

4. Estimated full-load efficiency η 0.8

5. Full-load current in stator winding (amp) 𝐼𝑐 1.22 A

6. Internal diameter of stator D 3.74 in.

7. Peripheral velocity of rotor v 2000 fpm

8. Gross length of stator core 𝑙𝑎 5.45 in.

9. Net length of iron in stator core m 4.545 in.

10. Number of slots per pole per phase 2

11. Number of slots per pole 6

12. Number of stator conductors per slot 𝐶𝑠 4

13. Thickness of slot insulation 0.284 in.

14. Size of wires no. .24

15. Depth of stator slots d 0.3543 in.

16. Total stator copper loss (watts) W 3.28448 W

17. Weight of iron in stator core 4.40 lbs.

18. Number of slots 𝑛𝑠 36

19. Width of rotor slot 𝑤𝑟 0.453 in.

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 20. Full-load speed (rpm) 1790 rpm

Computation: use of Engineering Theories and principle:

No. of poles 𝑣 = 10 𝑥 (60 𝐻𝑧)𝑥 (4)

120∗60 = 2000 𝑓𝑝𝑚

p= = 4.029
1790

Gross length of stator core

Volts per phase (delta)
165
E = 220 V 𝑙𝑎 = = 5.45 𝑖𝑛
5.552

Current in stator windings Net length of iron in stator core

1
(746) 𝑙𝑛 = 0.9 𝑥 (5.45 − 0.4) = 4.545 𝑖𝑛.
𝐼𝑐 = 2
= 1.22 A
√3 𝑥 (220 𝑉) 𝑥 (0.78) 𝑥 (0.8)

Air gap flux per pole

Distribution factor
220 𝑥 108
180° 4 𝑝𝑜𝑙𝑒
ɸ= = 81070.85
2.22 𝑥 0.966 𝑥 60 𝑥 2109
d = 𝑝𝑜𝑙𝑒 𝑥 36 𝑠𝑙𝑜𝑡
≈ 81071 maxwells
d = 20°
Ohms per phase
36
𝑛= 1.854
4𝑥3 Ω= 0.173 * 2

𝑛=3
Ω= 0.1603 ohm
20
sin(3 𝑥 )
𝐾𝑑 = 2
20
IR drop per phase
2 𝑋 sin ( )
2

IR = 3.2 x 0.1603
𝐾𝑑 = 1.44

IR = 0.5132 V
Peripheral velocity

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 Total stator copper loss Losses in stator teeth

W= 2 x 0.5152 x 3.2 𝑊𝑠𝑡 = 0.0.25 x 60 x 1.1

W= 3.28448 W 𝑊𝑠𝑡 = 8.58 W

Losses in stator core Total stator iron losses

𝑊𝑠𝑐 = 0.675 x 60 x 4.40 𝑊𝑡 = 17.82 + 8.58

𝑊𝑠𝑐 = 17.82 W 𝑊𝑡 = 26.4 W

VI. CONCLUSION

After doing our design of experiment we learned that three-phase induction motors use a squirrel-cage

winding in the rotor. And also there are no electrical connections to the rotor, but current is induced into the

rotor windings by electromagnetic induction. The squirrel-cage winding produces a magnetic field that's

pushed and pulled by the stator magnetic field.

Due to the copper windings inside the motor, SCIMs with higher output power rating are heavier. The

rotor is supported by a steel shaft that must rotate. The shaft is allowed to rotate with the application of

different types of bearings and various lubrications. Synchronous speed, speed regulation and percent slip

are all calculations used in determining the speed of the rotor. Motor electrical characteristics such as

power factor and starting current are related to the electrical design of the motor. Lastly, SCIM have a

stable or almost constant rpm, and is suitable for many industrial applications.

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VII. RECOMMENDATION

Based on the experience and the data gathered during the operation of the design experiment, the

group recommend for the future researchers to use a squirrel cage induction motor with different output

power rating and make a comparison of data based on their new design of experiment.

The group also recommends applying the used squirrel cage induction motor in an industrial

application in order for the researchers to be more familiar with the operating characteristics of the squirrel

cage induction motor.

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VIII. BIBLIOGRAPHY

Books:

Still, A. and Siskind, C., (1954). Elements of Electrical Machine Design. New York: McGraw-Hill Book

Company, Inc.

Theraja, A., (2005). A Textbook of Electrical Technology. New Delhi: S. Chand & Company LTD.

Guru, B., (2001). Electric Machinery and Transformers. New York: Oxford University Press.

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