(677390326) LAB_MANUAL-NEW - Copy.pdf

8/18/2019 (677390326) LAB_MANUAL-NEW - Copy.pdf

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INDEX

24/07/2015 INTRODUCTION TO COMPUTER AIDED DESIGN

AND DRAFTING (CADD)1

1 07/08/2015SIMPLE DRAWING TO FAMILIARIZE

BASIC COMMANDS IN AUTOCAD6

2 07/08/2015 DC DOUBLE LAYER LAP WINDING 7

3 21/08/2015DC DOUBLE LAYER LAP WINDING WITH

EQUILIZER RING10

4 21/08/2015 DC DOUBLE LAYER WAVE WINDING 12

5 04/09/2015 DC DUMMY COIL WAVE WINDING 15

6 04/09/2015 THREE PHASE SINGLE LAYER MUSH WINDING 18

7 11/09/2015 AC DOUBLE LAYER LAP WINDING(FULL PITCHED) 20

8 18/09/2015 AC DOUBLE LAYER LAP WINDING(SHORT PITCHED) 22

9 25/09/2015HALF SECTIONAL END AND FRONT ELEVATION OF

DC GENERATOR24

10 25/09/2015RIGHT HALF SECTIONAL END ELEVATION OF

DC COMPOUND MOTOR27

11 09/10/2015HALF SECTIONAL END VIEW AND FRONT

ELEVATION OF SQUIRREL CAGE INDUCTION

MOTOR

29

12 09/10/2015 HALF SECTIONAL END VIEW AND FRONT

ELEVATION OF SLIP RING INDUCTION

MOTOR

31


ELEVATION OF THREE PHASE SALIENT POLE

ALTERNATOR

34

14 30/10/2015 FRONT ELEVATION OF CYLINDRICAL TYPE ROTOR 37


ELEVATION OF ROTATING ARMATURE TYPE

ALTERNATOR

39

16 03/11/2015

ELECTRICAL SCHEMATIC DRAWING OF

AN INSTALLATION WITH SUPPLIES FROM

A TRANSFORMER AND STAND BY DGSET

41

17 03/11/2015 ELECTRICAL SCHEMATIC DRAWING OF AN 11

KV INDOOR SUBSTATION FOR AN

INDUSTRY

43


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EE 010 707: Electrical CAD

VISAT, Elanji Page | 1

INTRODUCTION TO COMPUTER AIDED DESIGN AND

DRAFTING (CADD)

The art of representation of engineering objects and structures on a piece of paper is called

engineering drawing. CADD is a tool which can be opted for the same purpose. It is both a visual and

symbol based method of communication whose conventions are particular to a specific technical field.

CADD activity is centered on CADD workstation. The typical CADD workstation consists of the

following.

1. Powerful computers

2. Graphics and Application Software

3. Input device such as mouse or digitizer pad with pen

4. Communications hardware and software for networking

Computer-aided design (CAD) is the use of computer systems to assist in the creation, modification,

analysis, or optimization of a design. CAD output is often in the form of electronic files f or print,

machining, or other manufacturing operations.

CAD may be used to design curves and figures in two-dimensional (2D) space; or curves, surfaces,

and solids in three-dimensional (3D) space.

CAD is an important industrial art extensively used in many applications, including automotive,

shipbuilding, and aerospace industries, industrial and architectural design, prosthetics, and many more.

CAD is also widely used to produce computer animation for special effects in movies, advertising and

technical manuals, often called DCC digital content creation. CADD software is much more than just

drawing lines for design purposes by electronic means

The advantages of CADD system are

a. Various automatic features like fillets and chambers help increase the help of designing

b. CAD program enable us to easily draw polygons, ellipses, multiple parallel lines and multiple

parallel curves that comprise a design

c. The ability to “sna p” automatically to create particular geometric points and features will spread

the accurate positioning of line work.

d. CADD information is stored in digital form and hence irrespective of the size of the final printeddrawing, it is possible to accurately dimension components automatically.

http://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/Designhttp://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttp://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttp://en.wikipedia.org/wiki/2D_computer_graphicshttp://en.wikipedia.org/wiki/2D_computer_graphicshttp://en.wikipedia.org/wiki/2D_computer_graphicshttp://en.wikipedia.org/wiki/3D_computer_graphicshttp://en.wikipedia.org/wiki/3D_computer_graphicshttp://en.wikipedia.org/wiki/3D_computer_graphicshttp://en.wikipedia.org/wiki/Industrial_artshttp://en.wikipedia.org/wiki/Industrial_artshttp://en.wikipedia.org/wiki/Industrial_artshttp://en.wikipedia.org/wiki/Prosthesishttp://en.wikipedia.org/wiki/Prosthesishttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Special_effecthttp://en.wikipedia.org/wiki/Special_effecthttp://en.wikipedia.org/wiki/Special_effecthttp://en.wikipedia.org/wiki/Advertisinghttp://en.wikipedia.org/wiki/Advertisinghttp://en.wikipedia.org/wiki/Advertisinghttp://en.wikipedia.org/wiki/Digital_content_creationhttp://en.wikipedia.org/wiki/Digital_content_creationhttp://en.wikipedia.org/wiki/Digital_content_creationhttp://en.wikipedia.org/wiki/Digital_content_creationhttp://en.wikipedia.org/wiki/Advertisinghttp://en.wikipedia.org/wiki/Special_effecthttp://en.wikipedia.org/wiki/Computer_animationhttp://en.wikipedia.org/wiki/Prosthesishttp://en.wikipedia.org/wiki/Industrial_artshttp://en.wikipedia.org/wiki/3D_computer_graphicshttp://en.wikipedia.org/wiki/2D_computer_graphicshttp://en.wikipedia.org/wiki/List_of_file_formats#Computer-aidedhttp://en.wikipedia.org/wiki/Design


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e. It has the ability to store entities, which is frequently applied on drawings, changes or/and

corrections can be easily made and it can be e-mailed or transmitted via internet instantly.

f. By using a macro or an add-on programming in CAD that allow customizing the program to

suit our specific needs and can implement our ideas which make the CAD system unique.

AUTOCAD

A product from Autodesk is a computer aided design program used by just about every

engineering and design office in the world. AutoCAD is used by Civil Engineers, Architects,

Electrical and Mechanical Engineers plus many other disciplines. AutoCAD software is one of the

wor ld’s leading 2-D and 3-D CAD design tools.

Basic drawing and modification tools used in AUTOCAD

TOOL COMMAND ALIAS DESCRIPTION

LINE L To draw line

ERASE E To erase unwanted objects

CIRCLE C To create a circle

ARC A To create an arc

RAY RAY To draw line to infinityPOLYGON POL To create a polygon having

required sides.

MOVE M To move objects from their

current location

COPY CO To copy an existing object

MIRROR MI To creates a mirror of selected

object

ARRAY AR To create copies of objects

arranged in both 2D and 3D

AUTOCAD ELECTRICAL

AutoCAD Electrical is AutoCAD software for controls designers, purpose-built to create and

modify electrical control systems. Autodesk, a world-leading supplier of software, provides tools that

let viewers experience ideas before engineering to be real.


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It contains all the functionality of AutoCAD and a comprehensive set of tools for automating

control engineering tasks, such as building circuits, numbering wires, and creating bills of material.

AutoCAD Electrical provides a library of more than 650,000 electrical symbols and components,

includes real-time error checking, and enables electrical and mechanical teams to collaborate on digital

prototypes built with software. This software makes it even easier to save time, reduce errors, and create

innovative electrical control designs.

ADVANTAGES OF USING ELECTRICAL CAD

Itis having:-

1. Full AutoCAD Functionality

2. Familiar AutoCAD Interface

3. Powerful Drafting Tools

4. Comprehensive Symbol Libraries

5. Electrical-Specific Drafting Features

6. Real-time Error Checking : Avoid costly errors at build time by catching and removing errors

during design

7. Schematic Design Tools

8. Panel Layout Tools

9. Terminal Management Tools

10. PLC I/O Tools: - The PLC module builder makes it easy to add PLC I/O modules to the standard

library. If desired modules are not included in the currently library

11. Symbol Builders:-Built on top of the AutoCAD Block Editor, the Symbol Builder helps create

electrical symbols and black boxes that can be added to the AutoCAD Electrical architecture.

12. Circuit Builder: - It reduces design time and increases dynamically generate rules-based

controls circuits based on defining functional requirements, such as components, wiring, ratings

etc.

SYSTEM REQUIREMENTS

System requirements for AutoCAD Electrical 2015

Operating System

Microsoft® Windows® 7 Enterprise Microsoft Windows 7 Ultimate Microsoft Windows 7 Professional Microsoft Windows 7 Home Premium Microsoft Windows 8/8.1 Microsoft Windows 8/8.1 Pro Microsoft Windows 8/8.1 Enterprise



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CPU Type

For 32-bit AutoCAD Electrical 2015:

Intel® Pentium® 4 or AMD Athlon™ Dual Core, 3.0 GHz or higher with SSE2 technology

For 64-bit AutoCAD Electrical 2015: AMD Athlon 64 with SSE2 technology AMD Opteron™ with SSE2 technology Intel® Xeon® with Intel EM64T support with

SSE2 technology Intel Pentium 4 with Intel EM64T support with

SSE2 technology

Memory 4 GB (8 GB recommended)

Display Resolution 1,280 x 1,024 (1,600 x 1,050 or higher

recommended) with True Color

Display

Card

Windows display adapter capable of 1024x768 with True Color capabilities. DirectX® 9

or DirectX 11 compliant card recommended but not required.

Installation 12.0 GB Disk Space

Network

Deployment via Deployment Wizard. The license server and all workstations that will

run applications dependent on network licensing must run TCP/IP protocol.

Either Microsoft® or Novell TCP/IP protocolstacks are acceptable. Primary login on workstations may be Netware or Windows.

In addition to operating systems supported for theapplication, the license server will run on the Windows Server® 2012, Windows Server 2012 R2, Windows Server 2008, and Windows 2008 R2 Server editions.

Citrix® XenApp™ 6.5 FP1

Digitizer WINTAB support

Tool Clips Media Player Adobe® Flash® Player v10 or up

.NET Framework .NET Framework Version 4.5



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2D / 3D CAD MODELS


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EXPERIMENT NO. 1

SIMPLE DRAWING TO FAMILIARIZE BASIC COMMANDS IN

AUTOCAD

AIM:

To draw a simple drawing shown below for getting familiar to basic shapes, drawing

commands/ tools, editing commands/tools and modifying commands/tools.

PROCEDURE:

1. Draw the LINE with given dimensions (length = 30mm)

2. From the end of the drawn LINE, by using relative polar co-ordinate system draw

another line of same dimension and repeat the steps.

3. Do the dimensions.

RESULT:

The given figure has been drawn in AutoCAD


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EXPERIMENT NO. 2

DC DOUBLE LAYER LAP WINDING

AIM:

slots.

Draw simplex progressive double layer l a p winding for a four pole DC machine with 16

THEORY:

Lap winding (parallel winding) is suitable for high current machines. Lap winding may be

classified into simplex and multiplex windings. The multiplex windings are used for low voltage high

current machines. Equalizer connections are used for minimizing circulating current. The cause for

circulating current is unequal induced emf across each circuit in a multi-pole lap winding. The

characteristics of lap windings are

a) The back pitch and front pitch must be odd.

b) The average pitch must be equal to pole pitch and is given by

Ya = (Yb+Yf)/2 = Z/P

Where Yb - back pitch

Yf - front pitch

Z-Number of coil side

P- Number of poles

c) If Yb>Yf the winding is progressive and Yb


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No. of poles, P=4

Ya = 8

Yb+Yf = 16; Yb=Yf+2

Therefore Yf=7 &Yb=9

Table can be prepared as follows,

SLOT

NO.

BACKPITCH

Yb = 9 FRONT PITCH

Yf = 7

1 1 + 9 = 10 10 – 7 = 3

2 3 + 9 = 12 12 – 7 = 5

3 5 + 9 = 14 14 – 7 = 7

4 7 + 9 = 16 16 – 7 = 9

5 9 + 9 = 18 18 - 7 = 11

6 11 + 9 = 20 20 – 7 = 13

7 13 + 9 = 22 22 – 7 = 15

8 15 + 9 = 24 24 – 7 = 17

9 17 + 9 = 26 26 – 7 = 19

10 19 + 9 = 28 28 – 7 = 21

11 21 + 9 = 30 30 - 7 = 23

12 23 + 9 = 32 32 – 7 = 25

13 25 + 9 = 34(2) 34 - 7 = 27

14 27 + 9 = 36(4) 36 - 7 = 29

15 29 + 9 = 38(6) 38 - 7 = 31

16 31 + 9 = 40(8) 40 - 7 = 33(1)

PROCEDURE:

1. Draw a vertical line using line command which shows a single conductor.

2. Take the offset option and draw the rest 31 conductors and do numbering.

3. Start the winding from the back side of conductor number 1.

4. Add the back pitch (9) and connect it to the next conductor (1+9 = 10).5. Subtract the front pitch (7) from the current conductor and connect it to the corresponding

conductor (10-7 = 3) on the front side.


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6. Repeat the above procedure till it reaches the front side of conductor number 1.

RESULT:

The winding diagram of simplex progressive double layer lap winding of a DC motor with 16 slots

and 4 poles is drawn using AutoCAD.


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EXPERIMENT NO. 3

DC DOUBLE LAYER LAP WINDING WITH EQUALIZER RINGS

AIM:

To draw simplex progressive double layer lap winding of a DC motor with 24 conductors and

4 poles. Also show the equalizer connections.

THEORY:

Lap winding (parallel winding) is suitable for high current machines. Lap winding may be classified

into simplex and multiplex windings. The multiplex windings are used for low voltage high currentmachines. Equalizer connections are used for minimizing circulating current. The cause for circulating

current is unequal induced emf across each circuit in a multi pole lap winding. The characteristics of

lap windings are:

a. The back pitch and front pitch must be odd.

The average pitch must be equal to pole pitch and is given by Ya=(Yb +Yf)/2=Z/P

Where Yb - back pitch

Yf- front pitchZ-Number of coil side

P- Number of poles

b. If Yb>Yf the winding is progressive and Yb


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Therefore Yf=5 &Yb=7

No. of equalizer rings =24/8=3

No. of connections to each equalizer rings = 2

Table can be prepared as follows,

SLOT

NO.

BACKPITCH

Yb = 7 FRONT PITCH

Yf= 5

1 1 + 7 = 8 8 - 5 = 3

2 3 + 7 = 10 10 - 5 = 5

3 5 + 7 = 12 12 - 5 = 7

4 7 + 7 = 14 14 -5 = 9

5 9 + 7 = 16 16 – 5 = 11

6 11 + 7 = 18 18 - 5 = 13

7 13 + 7 = 20 20 - 5 = 15

8 15 + 7 = 22 22 - 5 = 17

9 17 + 7 = 24 24 - 5 = 19

10 19 + 7 = 26 (2) 26 - 5 = 21

1121 + 7 = 28 (4)

28 - 5 = 2312 23 + 7 = 30 (6) 30 - 5 = 25 (1)

PROCEDURE:


2. Take the offset option and draw the rest 23 conductors and do numbering.3. Start the winding from the back side of conductor number 1.

4. Add the back pitch (7) and connect it to the next conductor (1+7 = 8).

5. Subtract the front pitch (5) from the current conductor and connect it to the corresponding

conductor (8-5 = 3) on the front side.

6. Repeat the above procedure till it reaches the front side of conductor number 1.

7. Draw two horizontal lines for equalizer rings and do appropriate connections from conductors.


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RESULT:

The winding diagram of simplex progressive double layer lap winding of a DC motor with 24

slots and poles with equalizer connections is drawn using AutoCAD.


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EXPERIMENT NO:4

DC DOUBLE LAYER WAVE WINDING

AIM:

Draw developed diagram of two layer wave winding for a 4 pole DC machine with 13 slots.

THEORY:

Wave winding is also known as series winding. In wave winding the finish end of one coil under

one pole pairs connected to the start of a coil under the next pole pair. This means that the start of two

consecutive coils is nearly two pole pitch apart. The winding has the appearance of a wave and hence

it is called wave winding. The characteristic of wave winding are

a. Both back pitch (Yb) and front pitch (Yf) must be odd.

b. Back pitch and front pitch must be nearly equal to pole pitch and may be equal.

c. The average pitch Ya must be a whole number and is given by Yb = (Yb + Yf) /2.

d. For simplex progressive wave winding, the back pitch (Yb) and front pitch (Yf) are equal. i.e.Yb

= Yf.

e. In wave winding, there are only two parallel paths irrespective of the number of poles and only

two brushes are required.

CALCULATION:

No. of conductors or coil sides, Z = 13*2 = 26

No. of poles = 4

Ya = (Yb + Yf) / 2 = (Z+_2) / P =7 or 6

ie; Yb+Yf =7*2 = 14

Since Yb = Yf, then Yb=Yf=7

A table can be prepared as follows


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SLOT

NO.

BACKPITCH

Yb = 7

FRONT PITCH

Yf= 5

1 1+7 =8 8+7=15

2 15+7 =22 22+7 = 29 (3)

3 3+7=

10 10+7 = 174 17+7 =24 24+7 = 31 (5)

5 5+7 =12 12+7 = 19

6 19+7 = 26 26+7 = 33 (7)

7 7+7 = 14 14+7 = 21

8 21+7 =28 (2) 2+7 = 9

9 9+7 =16 16+7 = 23

10 23+7 =30(4) 4+7 = 11

11 11+7 =18 18+7 = 25

12 25+7 =32(6) 6+7 = 13

13 13+7 = 20 13+7 = 20

PROCEDURE:



3. Start the winding from the back side of conductor number1.

4. Add the back pitch (7) and connect it to the next conductor (1+7 =8).

5. Add the front pitch (7) from the current conductor and connect it to the

corresponding conductor (8+7 =15) on the front side.

6. Repeat the above procedure till it reach the front side of conduct or number 1.

RESULT:

The developed diagram of two layer wave winding for a 4 pole dc machine with 13 slots is

drawn using AutoCAD.


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EXPERIMENT NO:5

DC DOUBLE LAYER WAVE WINDING

(WITH DUMMY COILS)

AIM:

Draw developed diagram of two layer wave winding for a 4 pole DC machine with 22 slots.

THEORY:

In simplex wave winding the average pitch YA (or commutator pitch YC)should be a whole number.

Sometimes the standard armature punching available in the market have slots that do not satisfy the

above requirement, so that more (usually only one more) are provided and that can be utilized. These

extra coils are Dummy coils or Dead coils. The Dummy coil is inserted into the slots in the same way

as the others to make the armature dynamically balanced. At the same time it is not the part of the

armature.

a. Both back pitch (Yb) and front pitch (Yf) must be odd.

b. Back pitch and front pitch must be nearly equal to pole pitch and may be equal.

c. The average pitch Ya must be a whole number and is given by Yb = (Yb + Yf) /2.

d. For simplex progressive wave winding, the back pitch (Yb) and front pitch (Yf) are equal. i.e.Yb

= Yf.

e. In wave winding, there are only two parallel paths irrespective of the number of poles and only

two brushes are required.

CALCULATION:

No. of conductors or coil sides, Z = 22*2 = 44

No. of poles = 4

Ya = (Yb + Yf) / 2 = (Z+_2) / P =11.5

or 10.5


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SLOT

NO.

BACKPITCH

Yb = 7

FRONT PITCH

Yf= 5

1 1+11 =12 12+11=23

2 23+11 =34 34+11 = 45 (3)

3 3+11 =14 14+11 = 25

4 25+11 =36 36+11 = 47 (5)5 5+11 =16 16+11 =27

6 27+11= 38 38+11 = 49 (7)

7 7+11 = 18 18+11 = 29

8 29+11 =40 40+11 =51(9)

9 9+11 =20 20+11 = 31

10 31+11 =42 42+11 = 53(11)

11 11+11 =22

22+13 =35

12 35+11 =46(2) 2+11 = 13

13 13+11 =24 24+13 = 37

14 37+11=48(4) 4+11=15

15 15+11=26 26+13=39

16 39+11=50(6) 6+11=17

17 17+11=28 28+13=41

18 41+11=52(8) 8+11=19

19 19+11=30 30+13=43

20 43+11=54(10) 10+11=21

21 21+11=32 32+13=45(1)

PROCEDURE:



3. Start the winding from the back side of conductor number1.

4. Add the back pitch (11) and connect it to the next conductor (1+11 =12).

5. Add the front pitch (11) from the current conductor and connect it to

the corresponding conductor (12+11 =23) on the front side.

6. Repeat the above procedure till it reaches the front side of conduct or number 1.


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RESULT:

The developed diagram of two layer wave winding for a 4 pole dc machine with 13 slots is

drawn using AutoCAD.


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EXPERIMENT NO.6

THREE PHASE SINGLE LAYER MUSH WINDING

AIM:

To draw the winding diagram for a 4pole, 36slots, 3-phase mush connected armature of an induction

motor.

THEORY:

This is a single layer winding in which all coils have the same span. Each coil is first wound on

former making one coil side longer than the other. This winding is so arranged that the long and short

coil sides occupy alternate slots around the armature. The coils are of same span and there is only on

coil side per slot and the coil span should be odd.

CALCULATION:

Slots per pole = 36 / 4 = 9

Slots per pole per phase = 36/ (4*3) = 3 slots

Slot angle = 180/9 =20

Slot allotted to three phases are

R 1,2,3 10,11,12 19,20,21 28,29,30

B 4,5,6 13,14,15 22,23,24 31,32,33

Y 7,8,9 16,17,18 25,26,27 34,35,36

PROCEDURE:

1. Draw a vertical line represents single conductor and using OFFSET command, draw 32

conductors, such that the long and short coil sides occupy alternate slots.


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2. Since slots per pole per phase is 3 , each phase (R,Y,B) having 3 conductors under one pole

.This can be done either by using LAYER option or by giving red, yellow and blue colours

respectively.

3. Start the winding of R phase from slot number 1. Connect the winding from slot 1 to slot 10.

Similarly connect longest winding in one coil group to the next short one.

4. Start the winding of Y phase from slot number 7.Connect the winding from slot 7 to slot 16 and

so on.

5. Start the winding of B phase from slot number 13. Connect the winding from slot 13 to slot 22

and complete the winding as per the table.

6. Mark starting and finishing end of each phase coils.

7. Do the connections between the coil groups under each phase.

RESULT:

The winding diagram for a 4 pole, 36 slots, 3 phase mush connected armature of an induction

motor is drawn using AutoCAD.


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EXPERIMENT NO.7

AC DOUBLE LAYER LAP WINDING (FULL PITCHED)

AIM:

Draw a developed winding diagram of a double layer lap winding for a three phase, 6 pole,18

slots machine. Assume that the winding is full pitched.

THEORY:

Double layer windings are universally used for armature of synchronous generators and motors.

They can be either lap or wave type.

Double layer windings can be either 1) integral slot winding 2) fractional slots winding. When

the number of slots per pole per phase (spp) is an integer known as integral slots winding. When the

number of slots per pole per phase is not an integer, the winding is known as fractional slot winding.

CALCULATION:

Slot per pole per phase = 18/ (6*3) = 1 slot

For full pitch coil, pole pitch coil span = 18/6 =3

Angle between two consecutive slots = 180/3 = 60

= (380/18) *3 = 60

No. of slots by which phases are displaced = 120/60 = 2 slots

PROCEDURE:


conductors, such that bolded line and dotted line occupy alternate slots, since it’s double layer

winding.

2. Since slots per pole per phase is 1 , each phase (R,Y,B) having 2 conductors under one pole

.This can be done either by using LAYER option or by giving red, yellow and blue colours

respectively.


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3. Connect the front end coil side to the back end coil side of the same phase under next pole and

complete the winding.



RESULT:

The developed winding diagram of a double layer lap winding for a 3 phase, 6 pole, 18 slots

machine is drawn using AutoCAD (full pitched).


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EXPERIMENT NO.8

AC DOUBLE LAYER LAP WINDING (SHORT PITCHED)

AIM:

Draw the winding diagram for a 3 phase 4 pole machine having 24 slots. The coil span

reduced by one slot.

THEORY:

Double layer windings are universally used for armature of synchronous generators and motors.

They can be either lap or wave type.

Double layer windings can be either 1) integral slot winding 2) fractional slots winding. When

the number of slots per pole per phase (spp) is an integer known as integral slots winding. When the

number of slots per pole per phase is not an integer, the winding is known as fractional slot winding.

CALCULATION:

Slot per pole per phase = 24/ (4*3) = 2 slot

For full pitch coil, pole pitch coil span = 24/4 =6

Angle between two consecutive slots = 180/6 = 30

No. of slots by which phases are displaced = 120/30 = 4 slots

Since it is short pitched in one slot coil span = 5 slots

PROCEDURE:


conductors, such that bolded line and dotted line occupy alternate slots, since it’s double layer

winding.

2. Slots per pole per phase is 2 , each phase (R,Y,B) having 4 conductors under one pole .

3. Since it is short pitched by one slot, draw R phase having 3 conductors in the first group and

other phases with 4 conductors itself. From next coil group, draw the conductors with spp 4


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itself. This can be done either by using LAYER option or by giving red, yellow and blue colours

respectively.

4. Connect the front end coil side to the back end coil side of the same phase under next pole and

complete the winding.



RESULT

The winding diagram for a 3 phase, 4 pole machine having 24 slots is drawn (short pitched)

using AutoCAD.


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EXPERIMENT NO.9

HALF SECTIONAL END AND FRONT ELEVATION OF DC

GENERATOR

AIM:

To draw the half sectional end and front elevation of DC generator with the following details.

Diameter of shaft : 40

Diameter of armature : 415

Number of armature slots : 36

Dimension of armature slots :

Length of armature core :

35 × 12

240

Armature winding overhang on each side : 110

Diameter of commutator

1. Up to contact surface : 220

2. Up to riser : 240

No of spider legs : 6

Diameter of spider wheel : 210

Outside diameter of yoke : 840

Thickness of yoke : 40

Number of main poles : 4

Number of inter poles : 4

Height of main pole : 160

Width of main pole : 140

Height of inter pole : 150

Width of inter pole : 44

Shaft is supported by end plates.

Missing data may be assumed suitably. All dimensions must be in millimeters.


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THEORY:

DC machine convert either electrical power into mechanical power (dc motor) or mechanical power

into electrical power (dc generator) based on the principle of production of dynamically induced emf.

The main parts of dc machine are

1) Yoke: it provides mechanical support to the pole and end shields and low reluctance path to the

magnetic flux to complete the circuit. It is made up of cast iron.

2) Field magnets: it is having pole core and pole shoe. The pole core made up of cast iron or cast

steel laminations of 0.35 mm to 0.5 mm thickness. Pole shoe spreads flux into the airgap, also

it supports field winding.

3) Field winding: it is made up of insulated copper wire either shunt or series winding.

4) Armature Core: It is a laminated steel cylinder whose stampings are 0.35mm to 0.5 mm thick

and having slots on the outer periphery.

5) Commutator: It is to facilitate collection of current from armature conductors. It rectifies the

ac induced in armature conductor into unidirectional current for the external loads.

6) Brush Holders: Used to hold the brush against the commutator surface.

PROCEDURE:

1. Draw the shaft with diameter 40mm

2. Draw the armature with diameter 415mm.

3. Draw a single armature slot with the given dimension on the surface of the armature.

4. Use polar array to construct 36 such slots on the periphery of armature

5. Draw the yoke with thickness 40mm.

6. Draw the main pole with given dimension on the vertical axis. Draw field windings Use polar

array to construct 4 such poles around the armature.

7. Draw the interpole with given dimensions and construct around the armature. Provide suitable

hatch to yoke and shaft.

8. Construct the hook on top of the generator and legs for mounting the generator with suitable

dimensions.

9. Provide provision of screws, nut &bolts for mounting the field poles to yoke and for mounting

armature to spider wheel.

10.Do the dimensions and make it half sectional view.

11. The diameter of shaft, rotor and stator can be projected from end view.

12. Draw the armature core length with 240 mm and overhangs with 110mm on each side.


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2) Field magnets: it is having pole core and pole shoe. The pole core made up of cast iron or cast

steel laminations of 0.35 mm to 0.5 mm thickness. Pole shoe spreads flux into the air gap, also

it supports field winding.

3) Field winding: it is made up of insulated copper wire and consists of both shunt and series

winding. The shunt coil has large number of turns and series winding has large conductor

cross section and lesser turns, which is placed below shunt field.

4) Armature Core: It is a laminated steel cylinder whose stampings are 0.35mm to 0.5 mm thick

and having slots on the outer periphery.

5) Commutator: It is to facilitate collection of current from armature conductors. It rectifies the

ac induced in armature conductor into unidirectional current for the external loads.

6) Brush Holders: Used to hold the brush against the commutator surface.

PROCEDURE:

1. Draw the shaft with diameter 83 mm

2. Draw the armature with diameter 406 mm.

3. Draw a single armature slot with the given dimension on the surface of the armature.

4. Use polar array to construct 39 such slots on the periphery of armature.

5. Draw the yoke withoutsidediameter840mmand thickness60mm.

6. Draw them in pole with given dimension on the vertical axis. Draw shunt field windings ofthickness 30 mm and series winding of thickness 20mm by choosing suitable length and

hatch it. Use polar array to construct 4 such poles around the armature.

7. Draw the inter pole with given dimensions and construct around the armature.

Provide suitable hatch to yoke and shaft.

8. Construct the hook on to pole of the motor and legs for mounting them rotor with suitable

dimensions.

9. Provide provision of screws, nut & bolts for mounting the field poles to yoke

and for mounting armature to spider wheel.

10. Do the dimensions and make it right half sectional view.

RESULT:

The right half sectional end elevation of DC compound motor has drawn.


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EXPERIMENT NO.11

HALF SECTIONAL END VIEW AND FRONT ELEVATION OF

SQUIRREL CAGE INDUCTION MOTOR

AIM:

To draw the half sectional end view and front elevation of a 3 phase, 415V, 5HPsquirrel cage

induction motor with the following dimensions.

Outside diameter of stator Stamping : 230

Inside diameter of stator stamping : 164

Thickness of stator frame : 25

Length of stator core : 120

Stator slots (a) open type

(b) Number : 36

(c) Size : 15* 8

Air gap : 2

Outer diameter of rotor stamping : 160

Inside diameter of rotor stamping : 35

Shaft diameter: at centre : 35

At bearing : 30

The rotor has totally closed type slots and contains bare conductors short circuited at both ends.

Missing data may be assumed suitably. All dimensions are in millimeters.

THEORY:

Most commonly used AC motor is Induction motor since it is rugged in construction, require

less maintenance etc. Three phase induction motor is widely used for industrial applications.

The main parts of squirrel cage induction motor are,

Stator: It consists of cast fabricated rolled steel frame and laminated hollow cylindrical core of CRGO.

Laminations are separated from each other by varnish/paper. Inner periphery slots (open/semi

closed/closed) are provided to house stator windings.


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Rotor : It consist of insulated silicon steel stampings having 0.3 to 0.5 mm thickness, which are keyed

directly to shaft .The outer periphery of rotor core is provided with slots to house the rotor windings,

the bars are braced to end rings.

End cover: it is bolted with stator frame on each side and contains bearings in which rotor shaft is

supported. Ball or roller bearing is commonly used.

PROCEDURE:

For drawing end view:

1. Draw the shaft with diameter 35 mm by using CIRCLE command.

2. Construct the rotor with outer diameter 160 mm.

3. Choose suitable dimension for the rotor slots to house the rotor windings and construct

them on the outer periphery of the rotor by using ARRAY command.

4. Construct the stator stampings with inside diameter 164 mm and outside diameter 230 mm.

Place 36 stator slots of dimension 15 × 8 mm inside the periphery of the stator frame. Construct

the yoke of the motor with thickness 25 mm i.e. diameter 280 mm.

5. Use EXPLODE command, the drawing can be exploded and delete the lower half section of

the end view.

6. Construct the hook on top of the motor and legs for mounting the motor with suitable

dimensions.

7. Provide suitable hatch to yoke and shaft.

8. Give detailing on the drawing by using suitable commands.

For drawing Front elevation:


2. Mark the stator core length as 120 and draw the rest of the parts of the machine

3. Take the shaft diameter as 30 at the bearings.

4. Draw other parts of the machine such as fan, bearing cover, eye bolt, end cover etc and make

it half sectional view.

RESULT:

The half sectional end view and front elevation of a 3 phase, 415V, 5HPsquirrel cage induction

motor is drawn using AutoCAD.


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EXPERIMENT NO. 12


SLIP RING INDUCTION MOTOR

AIM:

To draw the half sectional end view and front elevation of a 3 phase, 400V, 7.5HP, 1400 rpm

slip ring induction motor with the following dimensions.

Outside diameter of stator Stamping : 288




Stator slots (a) open type

(b) Number : 36

(c) Size : 18×6

Air gap: 2

Outer diameter of rotor stamping : 212

Inside diameter of rotor stamping : 36

Rotor slots (a) open type

(b) Number : 36

(c) Size : 12×8

Shaft diameter: at centre : 36

At bearing : 32

The stator frame has 8 and rotor stamping have 4 equally spaced ducts for ventilation. Missing data

may be assumed suitably. All dimensions are in millimetres.

THEORY:

Most commonly used AC motor is Induction motor since it is rugged in construction, require less

maintenance .The advantages of slip ring induction motor are

(1) It is having high starting torque with low starting current


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(2) speed can be adjusted by inserting resistance on rotor side

The main parts of slip ring induction motor are:

Stator: It consists of cast fabricated rolled steel frame and laminated hollow cylindrical core of CRGO.

Laminations are separated from each other by varnish/paper. Inner periphery slots (open/semi

closed/closed) are provided to house stator windings.

Rotor: It consist of insulated rotor slots with copper conductors similar to stator windings. Wave

windings are usually adopted and end of star/delta connected rotor are brought to three slip rings

mounted on shaft. External resistance can be connected to the rotor windings through brush and slip

ring.

End cover: it is bolted with stator frame on each side and contains bearings in which rotor shaft is

supported. Ball or roller bearing is commonly used.

Slip rings: Slip rings are made up of either brass or phosphor bronze, insulated from motor shaft and

are fitted on the shaft extension.

PROCEDURE:


1. Draw the shaft with diameter 36 mm by using CIRCLE command.

2. Construct the rotor with outer diameter 212 mm.

3. Draw rotor slots (open type, 36 no’s) to house the rotor windings and construct them on

the outer periphery of the rotor by using ARRAY command.


Place 36 stator slots of dimension 18 × 6 mm inside the periphery of the stator frame. Construct

the yoke of the motor with thickness 31mm.

5. Use EXPLODE command, the drawing can be exploded and delete the lower half section of

the end view.

6. Construct the hook on top of the motor and legs for mounting the motor with suitable

dimensions.

7. Provide suitable hatch to yoke and shaft.

8. Give detailing on the drawing by using suitable commands.


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2. Mark the stator core length as 106 and draw the rest of the parts of the machine


4. Show brushes and slip rings at the right end of the shaft.



RESULT:

The half sectional end view and front elevation of a 3 phase, 400V, 7.5HP, 1400 rpm slip ring

induction motor is drawn.


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EXPERIMENT NO.13

HALF SECTIONAL END VIEW AND FRONT ELEVATIONOF

3 PHASE SALIENT POLE ALTERNATOR

AIM:

Draw the half sectional end view and front elevation of a 25kVA, 400V, 1500 rpm, 3phase

alternator, the rotor is salient pole type. The main dimensions are:

Outside diameter of stator stamping : 400




Number of stator slots : 48

Dimension of stator slots : 32×12

Air gap : 2

Axial length of pole : 135

Pole Width : 70

Pole height with pole shoe : 75

Height of pole shoe : 18


At bearing : 55

Missing data may be assumed suitably. All dimensions are in millimetres.

THEORY:

An alternator (synchronous generator) is an electrical machine which converts the energies of

coal, gas, water etc. to alternating current, Based on Faradays laws of electromagnetic induction. The

frequency of generated emf can be defined as f= PNs/(120) where P is the number of poles and Ns is

the synchronous speed. An alternator can be classified as (1) rotating armature type and (2) rotating

field type. Due to many advantages, the field system is made rotating and armature winding is placed

on the stator. Following are the main parts of an alternator


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STATOR : It consist of cast iron yoke inside which is fitted a hollow cylindrical laminated core having

slots on inner periphery. The core is made up of CRGO or sheet steel stamping.

ROTOR : Rotor will supply necessary field flux to the air gap. Mainly two types of rotors are used

(1) SALIENT POLE TYPE ROTOR

(2) NON SALIENT POLE/CYLINDRICAL /TURBO ROTOR

In salient pole type rotor, poles are projected, attached to a spider. Spider may be a

fabricated cast steel wheel fitted on the shaft. Poles are made up of laminations riveted together to form

filed core, which carry field winding and are connected in series, excited by DC supply. The pole face

carries damper winding on its slots.

CALCULATION:

Speed of alternator (N) = 1500 rpm

Frequency (F) = 50 Hz

Therefore, number of poles (P) = 4

PROCEDURE:


1. Draw the shaft with diameter 70 mm using CIRCLE command.

2. The dimension of the poles is 75 × 70 mm including pole shoe. Draw 4 such poles placed at

90o apart around the periphery of the rotor shaft using POLAR ARRAY.

3. Choose suitable thickness and height for the rotor windings


Place 48 stator slots of dimension 35 × 12 mm inside the periphery of the stator frame.

5. Construct the stator frame having thickness 36mm.

6. Provide suitable HATCH to yoke and shaft.

7. Construct the hook on top of the alternator and legs for mounting the alternator with suitable

dimensions.

8. Provide provision of screws, nut & bolts of suitable dimension for mounting the field poles

rotor.


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2. Mark the pole axial length as 135mm and draw the rest of the parts of the machine.


4. Draw other parts of the machine such as fan, bearing cover, eye bolt, end cover etc. and

make it half sectional view.

RESULT:

Half sectional end view and front elevation of a 25kVA, 400V, 1500 rpm, and 3phase salient

pole alternator is drawn using AutoCAD.


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EXPERIMENT NO.14

FRONT ELEVATION OF CYLINDRICAL TYPE ROTOR

AIM:

Draw the slots and front elevation of a cylindrical (turbo) rotor of300MVA, 11KV, 3000rpm,

50 Hz air cooled turbo alternator from the following details:

Core Length : 2800

Stator Bore Diameter : 830

Air gap : 20

Diameter of rotor : 790

Number of wound slot : 16


THEORY:


coal, gas, water etc. to alternating current, based on Faradays laws of electromagnetic induction. The

frequency of generated emf can be defined as f= PNs/(120) where P is the number of poles and Ns is

the synchronous speed. An alternator can be classified as (1) rotating armature type and (2) rotating

field type. Due to many advantages, the field system is made rotating and armature winding is placed

on the stator. Following are the main parts of an alternator

STATOR : It consist of cast iron yoke inside which is fitted a hollow cylindrical laminated core having

slots on inner periphery. The core is made up of CRGO or sheet steel stamping.

ROTOR : Rotor will supply necessary field flux to the air gap. Mainly two types of rotors are used

(1) SALIENT POLE TYPE ROTOR

(2) NON SALIENT POLE/CYLINDRICAL /TURBO ROTOR

Non salient pole rotor consists of a smooth forged steel cylinder having a number of slots

milled out at intervals along the outer periphery and parallel to the shaft to accommodate the field

winding. The field windings are concentric type. Generally two third of the rotor is wound and the rest

one third is left to form the field pole arc. Here the solid field poles themselves act as sufficient dampers


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PROCEDURE:

1. Draw the rotor with diameter 790 mm and make 16 slots on the periphery.

2. Project from the rotor, draw the front view of rotor, as core length 2800mm and draw slots

on the periphery.

3. Do dimensions and complete the diagram.

RESULT:

The slots and front elevation of a turbo rotor of 300MVA, 11KV, 3000rpm, and 50 Hz air cooled

turbo alternator is drawn using AutoCAD.


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EXPERIMENT NO.15


ROTATING ARMATURE TYPE ALTERNATOR

AIM:

Draw the half sectional end view and front elevation of a Rotating armature type alternator.

The main dimensions are:

Outside diameter of stator stamping : 400



Length of rotor core : 135

Number of rotor slots :

Dimension of rotor slots :

Air gap :

48

32 ×12

2

Axial length of pole : 135

:Pole Width : 70

Pole height with pole shoe : 75

Height of pole shoe : 18


at bearing : 55


THEORY:


coal, gas, water etc. to alternating current, based on Faradays laws of electromagnetic induction. The

frequency of generated emf can be defined as f= P Ns/(120) where P is the number of poles and Ns is

the synchronous speed. The revolving armature alternator is similar in construction to the dc generator,


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in that the armature rotates through a stationary magnetic field. The revolving armature alternator is

found only in alternators of low power rating and generally is not used. In this, the generated ac voltage

is applied unchanged to the load by means of slip rings and brushes.

PROCEDURE:


1. Draw the shaft with diameter 70 mm using CIRCLE command.

2. Choose suitable thickness for the rotor and place 48 stator slots of dimension 35 × 12 mm

outside the periphery of the rotor frame.


4. The dimension of the poles is 75 × 70 mm including pole shoe. Draw 4 such poles placed at

apart around the periphery of the rotor shaft using POLAR ARRAY.

5. Construct the stator frame having thickness 36mm.

6. Provide suitable HATCH to yoke and shaft.

7. Construct the hook on top of the alternator and legs for mounting the alternator with suitable

dimensions.

8. Provide provision of screws, nut & bolts of suitable dimension for mounting the field poles

rotor.



2. Mark the armature core length as 135mm and draw the rest of the parts of the machine.




RESULT:

The half sectional end elevation and front elevation of rotating type alternator has been drawn

using AutoCAD.


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Load current of 50KW 3-phase load

Total connected load

=

=

50 × 1.7 = 85 A.

75 KW + 75 KW + 75 KW + 50 KW = 275 KW

Total current drawn by the loads

=

=

275/0.8 KVA = 344KVA

275 × 1.7 = 467.5 A

Maximum Demand = Connected Load × 0.65 = 344 KVA × 0.65

EXPERIMENT NO.16

ELECTRICAL SCHEMATIC DRAWING OF AN INSTALLATION

WITH SUPPLIES FROM A TRANSFORMER AND STANDBYDG SET

AIM:

To draw the single line schematic of an electrical installation having three numbers of 100

HP motor and a 50 KW 3-phase load with a diesel generator set with necessary metering and protection

equipment for back-up.

THEORY:

For every installation above 50 KVA of connected load should be supplied through a

11kV/415V, three phase transformer of suitable rating. In Indoor substations, all equipment of the

substation are installed within the station. .Necessary protection and metering instruments should be

provided at both the primary and the secondary side. HT SFU should be provided at the 11KV side and

4P MCCB should be provided at secondary for protection. The supply from the back-up generatorshould be provided to MSB/LT panel through 4P MCCB with necessary metering equipment.

The supply from the back-up generator and transformer should be supplied to MSB/LT

panel through. This relay automatically connects DG to LT panel when main supply power fails and

disconnects the DG when the main power supply restores. This relay ensures electrical and mechanical

interlocking between DG and main power supply.

CALCULATION:

Power of induction motor = 100 HP = 75 KW.

Full load current of induction motor = 75 × 1.7= 127.5 A


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= 224 KVA

Since the connected load is 344 KVA, choose 400 KVA, 11kV/415V transformer for main supply and

400 KVA DG as back-up.

Permissible Full load current at primary side of transformer = 400/19 = 21 A

Permissible Full load current at secondary of transformer = 400 × 1.33 = 532 A

Permissible Full load current of DG = 400 × 1.4 = 560 A

Choose 630 A, 415 V, 4P MCCB as circuit breaker on the primary of transformer and for DG. Choose

630A, 11kV High Tension Switch Fuse Unit (HT-SFU) with 20A fuse as circuit breaker in primary

side. Use a 100/5A CT and 11kV/110V PT and an energy meter for metering in HT side. Use a 100/5A

CT in neutral earthing for sensing the earth fault.

Use 3C × 150 SQ.MM cable 11kV grade in primary side and 3 runs of 3.5C × 300 SQ.MM LT cablein secondary of transformer.

Use 2 runs of 3.5C × 400 SQ.MM LT cable for the output of DG.

Use a 600/5A CT for sensing the output current and for measuring the power supplied and current in

each phase of DG.

Use a 125/5A CT in neutral earthing for sensing the earth fault in DG.

In the LT panel/MSB, use 250A, 4P, MPCB for protection of induction motors and three phase star delta starter

for starting the motor and 100A, 4P MCCB for protection of three phase load.

RESULT :

The single line schematic of an electrical installation having three numbers of 100 HP motorand a 50 KW 3-phase load with a diesel generator set with its necessary metering and protection

equipment for back-up has been drawn by using AutoCAD.


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EXPERIMENT NO.17

ELECTRICAL SCHEMATIC DRAWING OF AN 11k V INDOOR

SUBSTATION FOR AN INDUSTRY

AIM:

To draw the single line schematic of an electrical installation required for an industry with two

diesel generator set with necessary metering and protection equipment for back-up.

THEORY:

Sub stations serve as sources of energy supply for the local areas of distribution in which they

are located. In Indoor substations, all equipment of the substation are installed within the station.

Necessary protection and metering instruments should be provided at both the primary and the

secondary side. HT SFU should be provided at the 11KV side and 4P MCCB should be provided at

secondary for protection.

Air circuit breaker with 4 pole EDO/ SC/ OC with UV set is provided on the LT side as well as

on the bus bar through AMF panel. , so that one generator set can operate along with KSEB supply.

Permissible full load current in primary side of transformer= 750/19 = 40 A

Permissible full load current in secondary side of transformer = 750 ×1.33 =998 A

Permissible full load current of DG = 380 × 1.4 = 532 A

Maximum Demand = Connected Load × 0.65 = 695 KVA × 0.65

= 452 KVA

Total connected load on the bus bar is 695 k VA and considering future expansion choose the

transformer of 11k V /433V , 750 k VA with ONAN cooling and OLTC. The transformer can be of

dry type also.

Choose 600 A, 11KV, contactor switch on the HT side which is connected to a alarm hooter. Choose

630A, 11kV High Tension Switch Fuse Unit (HT-SFU) with 40A fuse as circuit breaker in primary

side. Use a 50/5A CT and 11kV/110V PT and an energy meter for metering in HT side. Use a 200/5A

CT in neutral earthing for sensing the earth fault.

Use 3C × 300 SQ.MM XLPE ( Cross linked poly ethylene) cable 11kV grade in primary side

and 3 runs of 3.5C × 300 SQ.MM 50KA,1250A LT cable in secondary of transformer.


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Use a 1000/5A CT for sensing the output current and for measuring the power supplied. Use 600/5A

CT to measure current in each phase of DG.

Use a 150/5A CT in neutral earthing for sensing the earth fault in DG.

IDMT (inverse definite minimum time) relay (51G) used to measure the fault current and it is connected to the

air circuit breaker.

Connect each load through Moulded case circuit breaker and CT, in the busbar. Three phase star delta starter is

used for starting the motor.

Capacitor banks are used for automatic control of power factor correction and maintains the power factor close

to the optimum level.


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GRAPHIC SYMBOLS USED FOR ELECTRICAL SCHEMATIC

WIRING ACCORDING TO NEC - 1985


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RESULT:

The single line schematic of an electrical installation for an industry with two diesel generator

set with its necessary metering and protection equipments for back-up has been drawn by using

AutoCAD.

Documents

(677390326) LAB_MANUAL-NEW - Copy.pdf