Introduction to electricity chapter 1

1. 1
Chapter 1
Getting Started
Getting Started
ELPT 1311 Basic Electrical Theory
Chapter 01_Getting Started
Introduction to Electricity by Paynter & Boydell and Pearson Illustrations
WHAT ABOUT EXP CALCULATOR BUTTON FOR ENGINEERING UNITS???
CHECK TO SEE IF ANOTHER METHODE

3. 3
Outline
• Electrical Careers
• Components and Symbols
• Electrical Meters
• Electrical Units of Measure
• Engineering Notation
Getting Started

4. 4
Electricians
• A person who has been trained to install, operate,
maintain and repair of:
- power circuits
- control circuits
- security circuits
- voice and video systems
- industrial motors and controls
• Must have a working knowledge of:
- basic principles of electricity and electronics
- reading and interpreting blueprints
- wiring techniques
- safe working practices
- the National Electric Code (NEC® )
- first aid
- hazardous materials
Electrical Careers

5. 5
Residential Electricians
• Install, maintain, and repair electrical circuits found in
houses apartments and condominiums
- power receptacles
- service panels
- junction boxes
- inside and outside lighting
- appliance power circuits
• Qualifications generally require:
- two or more years of classroom training plus on-the-job
training
- demonstrated knowledge and use of the National Electrical
Code (NEC® )
- installing, terminating and splicing high-voltage cables
Electrical Careers

6. A residential electrician

7. 7
Industrial and Commercial Electricians
• Install, maintain, and repair electrical circuits found in
industrial and commercial buildings including:
- power distribution circuits
- motor and environmental power and control circuits
- lighting circuits and fixtures
- service panels and junction boxes
- fire alarm systems
• Qualifications may require:
- five years training, classroom and including on-the-job training
- thorough knowledge of (NEC® )
- installing, terminating and splicing high-voltage cables
• Qualifications are demanding, but pay, benefits and job
stability are generally better
Electrical Careers

8. Industrial, Commercial Electrician

9. 9
Telecommunications Technician
• Install, maintain, troubleshoot and repair residential and
commercial data, audio, video, and security circuits that
include:
- low-voltage networks
- voice data transmission circuits
- local area networks (LANs)
- audio and video distribution systems
- security and access control systems
• Qualifications may include:
- three years classroom and on-the-job-training
Electrical Careers

10. Telecommunications Electrician Connecting
Wires To A Termination Block

11. 11
Outside Linemen
• Install and repair power and distribution lines including:
- overhead high-voltage lines
- distribution lines and circuits
- transformers and connectors
- power substations
- underground residential power systems
• Qualifications may include 3 ½ years of classroom and
on-the-job training including:
- proper use of rigging equipment
- operating a bucket truck
Electrical Careers

12. Outside Linemen Working On Power Lines Near
A Utility Pole

13. 13
Electronics Technicians
• A person who locates and repairs faults in electronic
systems and circuits including:
- using electronic test equipment
- performing periodic maintenance
- install new systems
• Qualifications generally require
- 2-year Associate Degree at a Community College
or equivalent
- military training and experience
Electrical Careers

14. Computer Technician
Electronics Technician

15. 15
Resistors
• A resistor is a component that is used to
restrict the flow of current in an electrical
circuit
- somewhat analogous to a valve in a water line
Components & Symbols
variable
resistor
R
fixed
resistor
R
potentiometer
R
SCHEMATIC
SYMBOLS

16. 16
Capacitors
• Capacitors are components that
store energy in an electrostatic field
• They may be called condensers in
older manuals
•Capacitors oppose a change in voltage polarized
capacitor
C
+
-
variable
capacitor
C
C
un-polarized
capacitor
SCHEMATIC
SYMBOLS
Ceramic Capacitors Polarized Capacitors
Components & Symbols

17. 17
Inductors
• Inductors are components that store energy in a
magnetic field
• They may be referred to as coils or chokes
SCHEMATIC
SYMBOLS
variable
coil
Components & Symbols
• Inductors oppose a
change in current flow

18. 18
Transformers
• Transformers are components that
contain one or more inductors in a
single structure
• Transformers are used to:
- change one voltage to another
- transfer electrical energy from
one circuit to another
Pole
Transformer
Power
Transformer
Transformer
SCHEMATIC
SYMBOLS
tapped
transformer
Components & Symbols

19. 19
Switches
• Switches are components used to make or break an
electrical circuit
SPST
SPDT
DPST
SCHEMATIC
SYMBOLS
Components & Symbols

20. 20
Fuses and Circuit Breakers
• A fuse is a component that automatically
breaks an electrical connection if the current increases
beyond a certain value
- circuit fuses “burn open” in the case of an overcurrent
condition and thereby protects the circuit
• A circuit breaker also operates on an
overcurrent condition to protect
a circuit, but they can be reset
and be used again
- circuit breakers “trip”
open to break the
current path of the
circuit
FUSES
THREE
PHASE
CIRCUIT
BREAKER
SINGLE PHASE
BREAKER
Components & Symbols

21. 21
Check Your Understanding
• What do all circuits have in common?
a) capacitors
b) transformers
c) current
d) switches
e) resistors
Getting Started

22. 22
Check Your Understanding
• What do all circuits have in common?
a) capacitors
b) transformers
c) current
d) switches
e) resistors
Getting Started

23. 23
Check Your Understanding
• What components are used to limit current?
a) voltages
b) resistors
c) conductors
Getting Started

24. 24
Check Your Understanding
• What components are used to limit current?
a) voltages
b) resistors
c) conductors
Getting Started

25. 25
Check Your Understanding
• A capacitor stores energy in a/n __________ field
a) electro-resistive
b) capacitive
c) inductive
d) electro-magnetic
e) electric
f) dynamic
Getting Started

26. 26
Check Your Understanding
• A capacitor stores energy in a/n __________ field
a) electro-resistive
b) capacitive
c) inductive
d) electro-magnetic
e) electric
f) dynamic
Getting Started

27. 27
Check Your Understanding
• An inductor stores energy in a/n __________ field
The best answer/response is:
a) resistive
b) capacitive
c) inductive
d) magnetic
e) electric
f) dynamic
Getting Started

28. 28
Check Your Understanding
• An inductor stores energy in a/n __________ field
The best answer/response is:
a) resistive
b) capacitive
c) inductive
d) magnetic
e) electric
f) dynamic
Getting Started

29. 29
Check Your Understanding
• What component is used to make or break an electrical
connection?
The best answer/response is:
a) capacitors
b) inductors
c) transformers
d) switches
e) resistors
Getting Started

30. 30
Check Your Understanding
• What component is used to make or break an electrical
connection?
The best answer/response is:
a) capacitors
b) inductors
c) transformers
d) switches
e) resistors
Getting Started

31. 31
Check Your Understanding
• What component must be replaced after it protects a
circuit from a high-current condition?
The best answer/response is:
a) capacitors
b) resistors
c) fuses
d) conductors
e) inductors
Getting Started

32. 32
Check Your Understanding
• What component must be replaced after it protects a
circuit from a high-current condition?
The best answer/response is:
a) capacitors
b) resistors
c) fuses
d) conductors
e) inductors
Getting Started

33. 33
Digital Multimeter (DMM)
• A digital multimeter (DMM) is a meter that allows the
measurement of most basic electrical properties
- voltage in AC or DC
- current in AC or DC
- resistance in ohms
• A direct current (DC) voltage
measurement is the actual
voltage value
• Alternating current (AC)
measurements are in
"root mean square values"
(rms) not peak values
Electrical Meters

34. 34
DC Voltage & Current
AC continually changes in
value
Household voltage =
120 volts rms
Household peak voltage =
155.16 volts peak
Household peak to peak voltage =
310.32 volts peak to peak
Electrical Meters
AC Voltage & Current
Amplitude of DC
DC (such as from a battery) does
not change in value from one
point in time to another point in
time
0 VOLTS
1.5 VOLTS
TIME 
Amplitude of AC (AC SINE WAVE)
TIME 

35. 35
Volt-Ohm-Milliammeter (VOM)
• The Volt-Ohm-Milliamp meter (VOM) is an analog
electrical measuring instrument that allows the
measurement of many
electrical properties
• The VOM also measures rms
values, not peak values
• Often not preferred over the
DMM because the DMM has
an easier read out and is
more accurate
Electrical Meters

36. 36
Quantity Symbol Definition Unit of Unit
measure Symbol
Current I Measure of electron flow Ampere A
Voltage E or V Force that causes electrons to flow Volts V
Resistance R Opposition to flow of electrons Ohms Ω
Power P Heat dissipated in a circuit Watts W
Capacitance C Storage capacity of a capacitor Farads f
Inductance L Storage capacity of an inductor Henries H
Reactance X Opposition to current by L or C Ohms Ω
Impedance Z Opposition to AC circuit current Ohms Ω
Frequency f Number of cycles per second Hertz Hz
Time t Time elapsed or between pulses Seconds s
Electrical Units of Measure

37. 37
Engineering Notation
• Engineering Notation is a shorthand method of
representing large and small numbers
• Examples: 1,000 meters = 1 kilometer
12,000 meters = 12 kilometers
28,400,000 Hz = 28.4 MHz (megahertz)
0.00025 A = 25 milliamps
0.0000025 f = 2.5 microfarads
0.095 s = 95 milliseconds
Engineering Notation

38. ENGINEERING NOTATION CHART
CONVERSION FACTORS

39. To convert a number "to" engineering notation
Divide the number by the conversion factor for desired prefix
Convert 5860 Hz to kHz
Use Calculator to Convert
Kilo = 1,000 or 103

40. To convert a number "to" engineering notation
Divide the number by the conversion factor for desired prefix
Convert 84,450,000 W to MW
Use Calculator to Convert
mega = 1,000,000 or 106

41. To convert a number "to" engineering notation
Divide the number by the conversion factor for desired prefix
Convert 0.00346 A to mA
Use Calculator to Convert
milli = 0.001 or 10-3

42. To convert a number "from" engineering notation
Multiply the number by the conversion factor indicated
Convert 5.86 kHz to Hz
5.860 kHz = 5860 Hz
Use Calculator to Convert
Kilo = 1,000 or 103
Hz

43. (84.5) MW (x) (6) (10X ) (=) 84,450,000 W
84.5 MW x 1,000,000 = 84,450,000 W
To convert a number "from" engineering notation
Multiply the number by the conversion factor indicated
Convert 84.45 MW to W
84.5 MW = 84,450,000 W
Use Calculator to Convert
mega = 1,000,000 or 106

44. (3.45) mA (x) (-3) (10X ) (=) .00346 A
3.45 mA x 0.001 = .00346 A
To convert a number "from" engineering notation
Multiply the number by the conversion factor indicated
Convert 3.46 mA to A
3.45 mA= .00346 A
Use Calculator to Convert
milli = 0.001 or 10-3

45. 45
Check Your Understanding
• Complete the following
- 0.750 A = ________________ mA
- 0.20 mA = ________________ A
- 1,550 W = ________________ kW
- 330 kV = ________________ V
- 112 μF = ________________ F
- 12,550,000 Ω = _________________ M Ω
- 0.000000456 F = _________________ nF
- 222 kΩ = _________________ Ω
Engineering Notation

46. 46
Check Your Understanding
• Complete the following
- 0.750 A = ________________ mA
- 0.20 mA = ________________ A
- 1,550 W = ________________ kW
- 330 kV = ________________ V
- 112 μF = ________________ F
- 12,550,000 Ω = _________________ M Ω
- 0.000000456 F = _________________ nF
- 222 kΩ = _________________ Ω
750
0.0002
1.55
330,000
0.000,112
12.55
456
222,000
÷ .001
÷ 1,000
÷ 1,000,000
÷ .000,000,001
x .001
x 1,000
x .000,000
x 1,000
Engineering Notation

47. The End
"Assignment"
Read Chapter 2