9A405.66.ppt automobile electrical system

Automobile electrical system

1. 9A405.66 1
Department Of Technical Education
Andhra Pradesh
Name : V. Harikrishna
Designation : Lecturer
Branch : Automobile Engg.
Institute : D.A.Govt.Polytechnic,Ongole
Semester : IVth
Subject : Automobile Electrical System
Subject Code : A405
Topic : Wiring Systems,Lighting and Accessories
Duration :100 min.
Sub topic : Wiring Systems & Types
Teaching Aids : Diagrams
Revised by : A.Gangadhara Rao

2. 9A405.66 2
Recap
In the last period ,we have discussed about,
•Over running clutch drive

3. 9A405.66 3
Objectives
On the completion of this period you will be able
to know
•Types of wiring systems
•Difference between types of wiring systems
•6v and 12v system

4. 9A405.66 4
Known to Unknown
•How can you supply the water from a reservoir to the
cultivated lands?
Ans: Through the major and minor canals, pipes and
by using pumps in case of lift irrigation.
•How do you supply electrical energy to various
accessories in a automobile?

5. 9A405.66 5
Introduction
•Tosupplyanelectricalenergytovariouselectricalunits
suchasheadlight,parkinglight,sideandstoplight,
directionindicators,routelight,radio,fan,heater,ignition
circuit,standingcircuit,chargingcircuitandwipermachine
etc.electricalwiresareusedtocarrytheelectricityfrom
thebattery.

6. 9A405.66 6
Diagram of Wiring System of Automobile
This figure shows various connections made from the
battery

7. 9A405.66 7
Types of Wiring Systems
•To light any bulb or to make any electrical connection, we
need both positive and negative supply wires.

8. 9A405.66 88
Types of Wiring Systems
Wire connections are made in two ways in automobiles.
There are,
•Earth return wiring system (single wire system)
•Insulated return wiring system (two wires system)

9. 9A405.66 99
Earth Return Wiring System
•TheEarthReturnWiringSystemiscalledasasinglewire
systemasitconsistofasingleinsulatedcable
•Thissinglecableconnectsthebatteryterminaltothe
electricalunitthroughaswitch
•Theunitisearthedtothemetalframeorenginewhichacts
asacommonreturnpathtothebatteryterminal

10. 9A405.66 1010
Circuit Diagram of Wiring Systems
Ground
Ground
Ground
Ground

11. 9A405.66 1111
Insulated Return System
•Inthissystemtwowiresi.e.,positiveandnegativewires
aretakenfromthebatterytoeveryunit
•Thissystemisusedonlyincostlyvehiclesandis
compulsoryforthevehicleswhichareusedforcarrying
explosives
Contd..

12. 9A405.66 1212
Insulated Return System
•Thissystemisusedinpetroloroiltankerandinmilitary
vehicles
•Incaseofshortcircuitinthissystem,theconcernedunit
onlyfails
•Herethevibrationsofthevehicledonoteffectthewiring
system

13. 9A405.66 1313
Differences between Earth return wiring
system& Insulated return wiring system
Earth Return Wiring System
•The earthreturn wiring
system consist only one
cable or wire
•It is cheaper than
Insulated return wiring
system
•This provides negligible
resistance
Insulated Return Wiring
System
•The Insulated return wiring
system consists of two
wires
•It is costlier
•This provides a definite
resistance
Contd..

14. 9A405.66 1414
•It is easier to trace out the
faults
•In case of short circuit the
whole system fails
•Vibrations of the vehicle
effect the wiring system
•It is difficult to trace out
the faults
•In case of short circuit the
concerned unit only fails
•Vibrations of the vehicle do
not effect the wiring
system

15. 9A405.66 1515
6v and 12v system
•Thebatteryisanaccumulatorofelectricalchargeora
energystoragedevice.
•Itischargedbythedynamodrivenbytheengineand
suppliescurrentforstartingtheengine.
•Itisalsousedforoperatingelectricaldevices.
Contd..

16. 9A405.66 1616
•The battery voltage is usually 6volts or 12volts and it
depends upon the number of cells in the battery
•If three cells of 2volts each are connected in series , it
becomes a 6 volt battery
•When six cells of 2 volts each connected in series, it
forms a 12 volt battery
Contd..

17. 9A405.66 1717
•In the recent years there is a departure from 6v electrical
system
•This is because, it is the current flow in amperes that
determines the size of conductors
•By doubling the voltage the same amount of electrical
power can be delivered with half the amperage
Contd..

18. 9A405.66 1818
•It follows that these conductors can be employed to
deliver the same electrical power
•This results into economy of the system
•Either one 12v battery or two 6v batteries in series are
used in electrical system

19. 9A405.66 1919
Summary
In this period , We have learnt about
•Types of wiring systems
•Battery voltage selection
•wiring systems

20. 9A405.66 2020
Quiz
(1)Thefollowingareusedtocarrytheelectricitytothe
unitfromthebattery
(a) Electrical wires
(b) Rubber cables
(c) Plastic wires
(d) None of the above

21. 9A405.66 2121
Quiz
(2)TheearthreturnwiringSystemiscalledasasinglewire
systemasitconsistof
(a) A single insulated cable
(b) A double insulated cable
(c) Both single &double insulated cable
(d) None of the above

22. 9A405.66 2222
Quiz
(3)Inaninsulatedreturnwiringsystemthefollowingare
takenfromthebatterytoeveryunit
(a) positive and positive wires
(b) positive and negative wires
(c) negative and negative wires
(d) none of the above

23. 9A405.66 2323
Quiz
(4)Thefollowingbatteriesinseriesareusedinelectrical
system
(a) either one 12v or two no. of 6volts batteries
(b) two no. of 12v batteries
(c) One 6volt and one12volts batteries
(d) none of the above

24. 9A405.66 2424
Assignment
(1)What is wiring? Describe the necessity of wiring of
an automobile?
(2) Mention the types of wiring systems ? and explain
any one of them.
(3) Compare the earth return wiring system with
insulated return wiring system .