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http://ndla.no/en/node/87808
http://ndla.no/en/node/51785#tools
http://ndla.no/en/node/52668?fag=42
http://ndla.no/en/node/80314 Tools Test
http://ndla.no/en/node/16092?fag=42 Safety Test
Beispiele:
Electric, Electrical or Electronic? Jan-Louis Nagel
Published: 09.06.2010 (20:44), Updated: 15.10.2013 (10:11)
Electric or electronic?
When a device is electronic it will run on controlled electric impulses. Small interconnected circuits
(semiconductors) enable the operator to control the device by giving the necessary impulse. Electronic
devices run on low voltage d.c (direct current) and have small IC-frames. Mobile phones, computers, MP3
players are examples of electronic devices. They will need a power source to work, such as mains voltage or
a battery.
An electric device is something that works directly on mains voltage, meaning they will need electric power
from the mains to work. An electric heater, an electric guitar, a toaster, an iron are examples of electric
devices. Some devices that are plugged directly to the mains may still run on low voltage d.c, as the high
voltage a.c. (alternating current) will be transformed and rectified inside the appliance.
The term electrical usually refers to the subject matter as such. You can do electrical studies and become an
electrical engineer.
Electric, electrical or electronic?
Fill in the correct word.
When a device is
it will run on controlled
impulses. Small interconnected circuits
(semiconductors) enable the operator to control the device by giving the necessary impulse.
devices run on low voltage DC (direct current) and have small IC-frames. Mobile phones, computers, MP3
players are examples of
a battery.
An
devices. They will need a power source to work, such as mains voltage or
device is something that works directly on mains voltage, meaning they will need
power from the mains to work. An
heater, an
guitar, a toaster, an iron are examples of
devices. Some devices that are plugged directly to the mains may still run on low voltage d.c, as
the high voltage a.c. (alternating current) will be transformed and rectified inside the appliance. The term
usually refers to the subject matter as such. You can do
engineer.
studies and become an
House Wiring / Schematic wiring diagrams / Electrotechnical Language
Make sure you understand these words before you read the text. Fill in any word you think is important.
1. solution
2. craftsman
3. customer
4. wiring
5. circuits
6. fuse
7. switch
8. socket
9. according
10. current
11. faulty
12. concealed
13. conduit
14. beam
15. bend (n)
16. junction box
17. mains
18. recommend
19. voltage
20. accessible
21. convenient
22. clamp (v)
23. skirting
24. sheathing
25. insulation
26. beams
27. bends
28. concealed
29. conduits
30. convenient
31. economical
32. electric
33. ground
34. insulation
35. mains
36. opne
37. skirting
38. sockets
39. wiring
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
amount
current
precaution
avoid
electrocuted
live
switch
circuit
fuse
fiddle (with) (v)
bracelet
conductive
insulate
appliance
damp
extinguisher
kit
severity
duration
cramp
voltage
convulsion
crucial
injured
resuscitation
Make the list longer, don’t mind if some words are double. Habe you an idea how Excel might help you to
clear the new list so that every word is included only once?
Preparing for the Installation
The construction of a new house will require cooperation
from the different craftsmen involved in the process. For
example, the architect and the electrician will have to
combine their skills to provide an optimal solution for the
customer when it comes to lighting and heating.
Then the electrician will set up the wiring diagram,
which must give full information about the electric
installation; the different circuits that go from the fusebox to all the outlets like switches, sockets and other
power-points. It will also tell you the kind of outlet /
switch which is to be put up where, e.g. a one-way or
two-way switch or whether the outlet will need to be
grounded. The diagram must also provide accurate
information about the required dimension of the cables
according to the amount of current they will carry. The
wiring diagram will later give important information in
case of troubleshooting a faulty system.
Concealed Wiring System
In a new house the wiring will usually be concealed, which means that the cables go in conduits inside the
walls and across the ceiling. Accordingly, the electrician must put up the conduits before the carpenter can
close the walls. The conduits go along posts and beams and must be mounted without sharp bends, and they
must be clamped to the beam where they enter the junction box. The cables are then pulled through the
conduits by means of a fish wire, or the conduits may be pre-cabled from the manufacturer. Usually there
will be three cables, one blue and one brown for the mains, and one green and yellow for ground connection.
Other colours may occur, but the ground cable will usually be two-coloured.
Concealed wiring gives a neat installation as all the cables are hidden. It is also more economical than an
open wiring system because it is quicker to put up and it will require less cable length, so it saves both time
and money. However, a concealed wiring system will be difficult to troubleshoot once the walls are up. This
is why for example built-in spotlights in the ceiling are recommended to go directly on the mains and not on
low-voltage via a transformer hidden in the ceiling, because the transformer is a weak link in such a system
and must be accessible for inspection.
Open Wiring System
When rehabilitating an old house it may be more convenient with an open wiring system since the walls are
closed. The cables are then clamped neatly next to the skirting along the floor and ceiling. The cables have a
double sheathing inside the insulation, and must be dimensioned according to the amount of current they
will carry. The cables must be mounted without any sharp bends to prevent damage to the sheathing and
insulation. Sockets, switches, and junction boxes are mounted on the wall and are connected in much the
same way as in the concealed system. The open system will take time to put up neatly, and it will require
more cable length as you have to follow all the bends and corners. The cables may be painted or covered
with wall-paper to make them less visible.
Remember that working with high voltage installations is highly dangerous. Safety regulations must be
observed at all times, both for your own safety (electric shock can kill) and to avoid the risk of fire due to a
faulty installation.
Tasks
Comprehension
1.
2.
3.
4.
What are the main advantages of a concealed wiring system versus an open wiring system?
Why should an open wiring system be put up without any sharp bends?
List some key-words about the information in you will get from a wiring diagram.
How will the different craftsmen (e.g. architect, carpenter, joiner, plumber, mason, and electrician)
need to cooperate during the construction of a new house?
And now it’s electrical tools!
Online: Electrical Tools Check the names of the Tools .
Safety first.
Working with electricity is highly dangerous. An electric shock can be fatal even with small amounts of
current. It is therefore essential that you take some safety precautions to avoid being electrocuted. Below are
listed some basic safety rules that should be observed when working with electricity.
1. Never work on a live installation. Make sure that the power is switched off, either by turning off the
main switch or by disconnecting the circuit you are going to work on. Put a note on the fuse box in
case someone else switches the power on by accident.
2. Never work alone on a high voltage installation. If something unforeseen should happen it could be
a matter of life and death to have someone there to give assistance.
3. Make sure that you know exactly what you are going to do before you start. Electric installations
are not for amateurs to fiddle with.
4. Remove rings, bracelets and watches. These things are highly conductive and may easily give you
the ground connection that is needed to give you an electric shock.
5. Always use insulated, clean tools. Keep your workplace tidy and concentrate on your work.
6. Two conditions are needed for you to get an electric shock: You must touch a live appliance, such as
an uninsulated cable or a terminal, and you must have a ground connection. To avoid being
earthed, it is smart to wear shoes with rubber soles, or stand on a rubber mat. For the same reason,
you should never work with wet hands or damp clothes, or in any damp or wet environment.
7. There should also be a fire extinguisher and a first aid kit at hand in case of emergency.
Electric Shock
The severity of an electric shock will depend on two factors - amount of current and duration of exposure to
electric current.
1. The amount of current. Even small amounts of current can be fatal; 10mA will give you a partial
shock and cramps and currents of 100mA and above will most likely be deadly. The human body
consists of nearly 75% water, so it is highly conductive. The voltage does not burn, but it will give
you serious convulsions and paralyze the muscles.
2. The shock will also depend on the amount of time a person is connected. If a person receives an
electric shock it can be hard for him to let go because of the cramps. Then it is crucial that you don't
grab the injured person by the skin to pull him away. In that way you will also get an electric shock.
Use a piece of dry cloth or some insulated object to pull him away.
Resuscitation Procedures
If current and voltage pass through a person's body, the heart will most likely stop and he will stop
breathing. It is therefore important to be familiar with first aid and resuscitation procedures, like mouth-tomouth and heart compression.
Tasks and Activities
Comprehension
1.
2.
3.
4.
What are the two conditions necessary to give you an electric shock?
What are the two conditions that will decide the severity of the shock?
How can you best avoid being grounded?
Which is more dangerous - voltage or current?
Electrical symbols and electronic circuit symbols are used for drawing
schematic diagram. Electronic components are parts of electrical & electronic circuits .
Find an image of the component and integrate it into the Word Chart like the „wire“ picture you see.
Symbol
Component name
Meaning
Wire Symbols
Electrical Wire
Conductor of electrical current
Connected Wires
Connected crossing
Not
Wires
Wires are not connected
Connected
Switch Symbols and Relay Symbols
SPST Toggle Switch
Disconnects current when open
SPDT Toggle Switch
Selects between two connections
Pushbutton Switch
(N.O)
Momentary switch - normally open
Pushbutton Switch
(N.C)
Momentary switch - normally closed
Jumper
Close connection by jumper insertion
on pins.
Solder Bridge
Solder to close connection
Ground Symbols
Earth Ground
Used for zero potential reference and
electrical shock protection.
Chassis Ground
Connected to the chassis of the circuit
Resistor Symbols
Resistor (IEEE)
Resistor reduces the current flow.
Resistor (IEC)
Potentiometer
(IEEE)
Adjustable resistor - has 3 terminals.
Potentiometer (IEC)
Variable Resistor /
Rheostat (IEEE)
Adjustable resistor - has 2 terminals.
Variable Resistor /
Rheostat (IEC)
Capacitor Symbols
Capacitor
Capacitor is used to store electric
charge. It acts as short circuit with AC
and open circuit with DC.
Capacitor
Power Supply Symbols
Voltage Source
Generates constant voltage
Current Source
Generates constant current.
AC Voltage Source
AC voltage source
Generator
Electrical voltage is generated by
mechanical rotation of the generator
Battery Cell
Generates constant voltage
Battery
Generates constant voltage
Lamp / Light Bulb Symbols
Lamp / light bulb
Generates light when current flows
through
Lamp / light bulb
Lamp / light bulb
Diode / LED Symbols
Diode allows current flow in one
direction only - left (anode) to right
(cathode).
Diode
Misc. Symbols
Motor
Electric motor
Transformer
Change AC voltage from high to low or
low to high.
Electric bell
Rings when activated
Buzzer
Produce buzzing sound
Fuse
The fuse disconnects when current
above threshold. Used to protect
circuit from high currents.
Fuse
Optocoupler
Opto-isolator
/
Optocoupler isolates connection to
other board
Loudspeaker
Converts electrical signal to sound
waves
Microphone
Converts sound waves to electrical
signal
Logic Gates Symbols
NOT Gate (Inverter)
Outputs 1 when input is 0
AND Gate
Outputs 1 when both inputs are 1.
NAND Gate
Outputs 0 when both inputs are 1.
(NOT + AND)
OR Gate
Outputs 1 when any input is 1.
NOR Gate
Outputs 0 when any input is 1. (NOT +
OR)
XOR Gate
Outputs 1 when inputs are different.
(Exclusive OR)
D Flip-Flop
Stores one bit of data
Solution Page
1. In a concealed wiring system the cables are hidden inside the walls and ceiling which gives the
installation a neat look. The system is also more economical than an open wiring system because it
requires less cable-length and takes less time to put up.
2. Because sharp bends may damage the insulation and sheathing.
3. The diagram gives information about the complete installation; all the outlets, switches and power
points, the dimension of the cables and which outlets that are grounded.
4. The different parts of a construction process have to be carried out in a certain order, e.g. the
electrician has to put down the cables in a heated floor before the mason can pour out the grout and
fit the tiles.
1.
2.
3.
4.
You must touch a live terminal and you must be grounded.
The amount of current and the period of time a person is connected.
Remove rings and watches, wear rubber soles and don't work in wet or damp environments.
They are both dangerous. Voltage will give you cramps so it is hard to let go, but current will burn
and cause damage to the heart.