This document is a comprehensive training module on reading electrical drawings and schematics, covering the history, types, and anatomy of technical drawings. It includes detailed sections on various electrical symbols, device numbers, and different types of electrical drawings such as single line diagrams and wiring diagrams, aimed at facilitating understanding and practical applications in electromechanical contexts. The course emphasizes the evolution of technical drawing methodologies and provides practical information for effective communication through these diagrams.

1. Prepared By : Eng. Ahmed Hegab
November. 2019
CERTIFIED ELECTROMECHANICAL
TECHNICIAN TRAINING MODULE (II)
READING ELECTRICAL DRAWING AND
SCHEMATICS

2. COURSE CONTENTS
 PART ONE :
INTRODUCTION TO TECHNICAL DRAWING
 PART TWO :
READING OF ELECTRICAL DRAWING

3. INTRODUCTION TO TECHNICAL DRAWING
PART ONE

4. MAIN HEADLINES
- TECHNICAL DRAWING HISTROY
- AIM OF USE
- TYPES OF TECHNICAL DRAWING
- ANATOMY OF A DRAWING
- ISOMETRIC (MECHANICAL) DRAWING

5. MAIN HEADLINES
- TECHNICAL DRAWING HISTROY
- AIM OF USE
- TYPES OF TECHNICAL DRAWING
- ANATOMY OF A DRAWING
- ISOMETRIC (MECHANICAL) DRAWING

6. Eng. AHMED M. HEGAB
Nov. 2019
• Technical drawing is a reproduction tool of a documenting
an architecture or an engineering design.
• Introduced in the 18th century using a contact print
process on light-sensitive blue sheets.
• In the early 1940s this design is changed to be blue lines
on a white background which called blue-lines.
• Now, drawing are replaced by whiteprints to reduce the
time, cost and increase accuracy.
INTRODUCTIONTOTECHNICALDRAWING TECHNICAL DRAWING HISTROY

7. Eng. AHMED M. HEGAB
Nov. 2019
Drawing Evolution
INTRODUCTIONTOTECHNICALDRAWING TECHNICAL DRAWING HISTROY

8. MAIN HEADLINES
- TECHNICAL DRAWING HISTROY
- AIM OF USE
- TYPES OF TECHNICAL DRAWING
- ANATOMY OF A DRAWING
- ISOMETRIC (MECHANICAL) DRAWING

9. Eng. AHMED M. HEGAB
Nov. 2019
 Drawings are used to convey the information about a
specific equipment like:
- Layout and Dimensions
- Location
- Details (assembly – contents – manufacture date…etc)
- Electrical Wiring
AIM OF USEINTRODUCTIONTOTECHNICALDRAWING
Language for
COMMUNICATION !!

10. MAIN HEADLINES
- TECHNICAL DRAWING HISTROY
- AIM OF USE
- TYPES OF TECHNICAL DRAWING
- ANATOMY OF A DRAWING
- ISOMETRIC (MECHANICAL) DRAWING

11. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF TECHNICAL DRAWING
• Electrical
• Mechanical
• Civil
• Architectural
• Piping / Plumbing
INTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
TYPES OF TECHNICAL DRAWINGINTRODUCTIONTOTECHNICALDRAWING
Civil Drawing

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Nov. 2019
TYPES OF TECHNICAL DRAWINGINTRODUCTIONTOTECHNICALDRAWING
Architecture Drawing

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Nov. 2019
TYPES OF TECHNICAL DRAWINGINTRODUCTIONTOTECHNICALDRAWING
Piping Drawing
Do We’ve this type
In ABB ?!
Do We’ve this type
In ABB ?!

15. MAIN HEADLINES
- TECHNICAL DRAWING HISTROY
- AIM OF USE
- TYPES OF TECHNICAL DRAWING
- ANATOMY OF A DRAWING
- ISOMETRIC (MECHANICAL) DRAWING

16. Eng. AHMED M. HEGAB
Nov. 2019
Drawing Size
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

17. Eng. AHMED M. HEGAB
Nov. 2019
Drawing Scale
ANATOMY OF A DRAWING
Types of Drawing Scale
Fraction Inch Decimal Inch SI Metric
INTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
Drawing Scale
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

19. Eng. AHMED M. HEGAB
Nov. 2019
 A generic engineering drawing can be divided into the
following six major areas or parts:
1- Title block
2- Grid system
3- Revision block
4- Notes
5- Legends
6- Engineering drawing (graphic portion)
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

20. Eng. AHMED M. HEGAB
Nov. 2019
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING
1‐ Title Block

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Nov. 2019
1‐ Title Block
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
2‐ Grid System
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
2‐ Grid System
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
What Do You Need To Locate Any Point In
A Certain Drawing
ANATOMY OF A DRAWINGINTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
3‐ Revision Block
ANATOMY OF A DRAWING
Difference
??
INTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
4‐ Drawing Notes
ANATOMY OF A DRAWING
Drawing Notes TypesDrawing Notes Types
For Illustrating For Change
INTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
ANATOMY OF A DRAWING
Illustrating Notes
INTRODUCTIONTOTECHNICALDRAWING

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Nov. 2019
ANATOMY OF A DRAWING
Illustrating Notes
INTRODUCTIONTOTECHNICALDRAWING

29. Eng. AHMED M. HEGAB
Nov. 2019
Change Notes
ANATOMY OF A DRAWING
• There are two common methods of indicating where a
revision has changed a drawing that contains a system
diagram.
• The first is the cloud method, where each change is
enclosed by a hand-drawn cloud shape,
• The second method involves placing a (circle or
triangle or other shape) with the revision number next
to each effected portion of the drawing.
INTRODUCTIONTOTECHNICALDRAWING

30. Eng. AHMED M. HEGAB
Nov. 2019
ANATOMY OF A DRAWING
Change Notes
INTRODUCTIONTOTECHNICALDRAWING

31. Eng. AHMED M. HEGAB
Nov. 2019
5‐ Drawing Legends
ANATOMY OF A DRAWING
• Legends are boxes drawn
on the drawing to illustrate
some of the common or
uncommon symbols used.
INTRODUCTIONTOTECHNICALDRAWING

32. Eng. AHMED M. HEGAB
Nov. 2019
Lines of Drawing
ANATOMY OF A DRAWING
Center Line
Extension Line
Object Line
Dimension LineHidden Line
INTRODUCTIONTOTECHNICALDRAWING

33. MAIN HEADLINES
- TECHNICAL DRAWING HISTROY
- AIM OF USE
- TYPES OF TECHNICAL DRAWING
- ANATOMY OF A DRAWING
- ISOMETRIC (MECHANICAL) DRAWING

34. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Types of 3D Drawing
One Point Two Point Isometric

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Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

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Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

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Nov. 2019
Definition
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
• A cube shown with this type of
projection pivots 45º to show two faces
on the projection plane instead of a
single face.
• Isometric projection is a pictorial
projection of an object and it is a
single view, in which all the three
dimensions of an object are revealed.

38. Eng. AHMED M. HEGAB
Nov. 2019
Characteristics
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
All lines parallel to axes
1, 2 and 3 are isometric
lines.
2 3
1
120º
The isometric lines are
angled at 30º.
The lines not parallel to
axes 1, 2 and 3 are
non-isometric lines.
The sides of the cube
and all planes parallel to
them are isometric
planes.
Axes 1, 2 and 3 form
120º angles between
one another.
The projection is isometric
(equal measures) because
the height of axis 1, the
length of axis 2 and the width
of axis 3 are all
proportionally reduced.

39. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

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Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

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Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

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Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

43. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

44. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

45. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

46. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Let’s do this together …

47. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Isometric Projection

48. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Isometric Projection

49. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Isometric Projection

50. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Example #1

51. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING
Example #2

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Nov. 2019
Example #3
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

53. Eng. AHMED M. HEGAB
Nov. 2019
INTRODUCTIONTOTECHNICALDRAWING ISOMETRIC (MECHANICAL) DRAWING

54. READING OF ELECTRICAL
DRAWINGS
PART TWO

55. MAIN HEADLINES
- ELECTRICAL SYMBOLS
- ELECTRICAL DEVICE NUMBERS
- TYPES OF ELECTRICAL DRAWING
- PRACTICAL APPLICATIONS

56. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

57. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

58. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

59. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

60. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

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Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

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Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS

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Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS
Opened contact
Closed contact
Disconnector 89
Circuit Breaker
Magneto-thermal
breaker

64. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL SYMBOLSREADINGOFELECTRICALDRAWINGS
Auxiliary relay
coil
Tilting
auxiliary relay
Time-delay
relay coil
Three-winding
three-phase
transformer
Three-winding
three-phase
transformer
Three-phase
transformer of
multiple taps with
on-load tap
changer

65. MAIN HEADLINES
- ELECTRICAL SYMBOLS
- ELECTRICAL DEVICE NUMBERS
- TYPES OF ELECTRICAL DRAWING
- PRACTICAL APPLICATIONS

66. Eng. AHMED M. HEGAB
Nov. 2019
ELECTRICAL DEVICE NUMBERSREADINGOFELECTRICALDRAWINGS
ANSI STANDARD FOR NUMBERING

67. MAIN HEADLINES
- ELECTRICAL SYMBOLS
- ELECTRICAL DEVICE NUMBERS
- TYPES OF ELECTRICAL DRAWING
- PRACTICAL APPLICATIONS

68. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
Single (One) Line Diagram [SLD]
Layout Drawing
Wiring (Connection) Diagram
Schematic Drawing
Block Diagram
Logic Diagram
Interconnection Diagram
READINGOFELECTRICALDRAWINGS

69. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
1. Single Line Diagram
READINGOFELECTRICALDRAWINGS
• Shows the overall connections and interactions
between equipment and relay system components but in
a simplified manner.
• Do not show the exact electrical connections of the
circuits, just a simplified description of the connections
among the different elements.
• Also may called one line diagram that emphasizes the
power system equipment and does cover all details of
system components but not with connection.

70. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWINGREADINGOFELECTRICALDRAWINGS
1. Single Line Diagram
• This diagram shows the
connections among the
different elements in a
substation.
• It is defined by :
– Nº of transformers
– Nº source and feeder
lines
– Buses configuration
– Switching elements
220 kV
L1
EB
L2 L3 L4 T1 T2 T3
MT
10L
- - - EB1
10L
- - - EB2
10L
- - -
50MVA 50MVA 50MVA
PB

71. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
2. Layout Diagram
READINGOFELECTRICALDRAWINGS
• Give all details about
each level in a certain
location with dimensions.
• All directions should be
mentioned (N-S, E-W).

72. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
3. Wiring Diagram
• A wiring diagram is a simplified conventional pictorial
representation of an electrical circuit or component.
• It shows the components of the circuit as simplified
shapes, and the power and signal connections between
the devices in details.
• Usually gives information about the relative position and
arrangement of devices and terminals on the devices, to
help in building or servicing the device.
READINGOFELECTRICALDRAWINGS

73. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
3. Wiring Diagram
• A wiring diagram is
often used to
troubleshoot problems
and to make sure that
all the connections have
been made and that
everything is present
READINGOFELECTRICALDRAWINGS

74. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
4. Schematic Diagram
• Schematic diagram shows, by means of graphic symbols,
the electrical connections and functions of a particular
circuit arrangement in details.
• Details will include specific terminal numbers of devices
and test switches to which connections are made.
• It shows the electrical relationship of all the various
components.
READINGOFELECTRICALDRAWINGS

75. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
5. Logic Diagram
READINGOFELECTRICALDRAWINGS

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Nov. 2019
TYPES OF ELECTRICAL DRAWING
5. Logic Diagram
READINGOFELECTRICALDRAWINGS

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TYPES OF ELECTRICAL DRAWING
5. Logic Diagram
READINGOFELECTRICALDRAWINGS

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Nov. 2019
TYPES OF ELECTRICAL DRAWING
5. Logic Diagram
READINGOFELECTRICALDRAWINGS

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Nov. 2019
TYPES OF ELECTRICAL DRAWING
6. Block Diagram
READINGOFELECTRICALDRAWINGS

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Nov. 2019
TYPES OF ELECTRICAL DRAWING
6. Block Diagram
READINGOFELECTRICALDRAWINGS

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Nov. 2019
TYPES OF ELECTRICAL DRAWING
7. Interconnection Diagram
READINGOFELECTRICALDRAWINGS

82. Eng. AHMED M. HEGAB
Nov. 2019
TYPES OF ELECTRICAL DRAWING
Other Technical Submittals
READINGOFELECTRICALDRAWINGS
 Spare Parts List.
 Ladder Diagram
 Bill of Material List
 General Arrangement.
 Electrical Load List.
 Electrical ( Test – Study – Calculation - etc) Reports

83. Eng. AHMED M. HEGAB
Nov. 2019
PRACTICAL APPLICATIONS
Now, Time for Practical Drawings
READINGOFELECTRICALDRAWINGS

84. Eng. AHMED M. HEGAB
Nov. 2019
Voltage Levels
• Low voltage : up to 1000 V
• Medium voltage : above 1000 V up to 35 kV
• High voltage : above 35 kV to 230 kV
• Extra high voltage : above 230 kv to 800 kv
• Ultra high voltage : above 800 kv to 1200 Kv
REMEMBER

85. THANKS
ENG. AHMED MOHAMED HEGAB
ahegab50@gmail.com