Electrical Fundamentals Parts Technician First Period Material Identification and Calculations 270103e

Electrical Fundamentals

Parts Technician

First Period

Material Identificationand Calculations

270103e

© 2012, Her Majesty the Queen in right of the Province of Alberta

Figure 1 - Commonly used electrical symbols.


Figure 2


Figure 3 - Carbon atom.


Figure 4 - Aluminum and copper atoms.


Figure 5 - Electrons moving in a wire.


Figure 6 - Semiconductors.


Figure 7 - Insulators.


Figure 8 - Hydrocarbon insulator.


Figure 9 - Insulation on a conductor.


Figure 10 - Insulation preventing conductor contact.


Figure 11 - Parallel twisted conductors.


Figure 12 - Plastic or vinyl insulation on wiring.


Figure 13 - Starter solenoid and alternator stator.


Figure 14 - Rear window defogger.


Table 1 - AWG and SI metric wire sizing.

Diameter

AWG Inches mm

4/0 0.46000 11.684 3/0 0.40960 10.404

2/0 0.36480 9.266

1/0 0.32490 8.252 1 0.28930 7.348

2 0.25760 6.543

3 0.22940 5.827 4 0.20430 5.189

5 0.18190 4.620

6 0.16200 4.115 7 0.14430 3.665

8 0.12850 3.264

9 0.11440 2.906 10 0.10190 2.588

11 0.09070 2.304

12 0.08080 2.052 13 0.07200 1.829

14 0.06410 1.628

15 0.05710 1.450 16 0.05080 1.290

17 0.04530 1.151

18 0.04030 1.024 19 0.03901 0.991

AWG = American Wire Gauge Standard CMA = Circular Mil Area


Figure 15 - Wire sizes.


Figure 16 - Trailer wiring cable.


Figure 17 - Protects battery terminals and cables.


Figure 18 - Insulation damaged and conductors shorted together.


Figure 19 - Protection of insulators and conductors.


Figure 20 - Iron filings placed over a permanent magnet.


Figure 21 - Horseshoe and bar magnets.


Figure 22 - Magnet and magnetic flux lines.


Figure 23 - Flux lines showing direction and parallelism (not crossing).


Figure 24 - Magnets attracting (unlike poles attract).


Figure 25 - Unlike poles attract and pull the magnets together.


Figure 26 - Like poles repel (magnets are forced apart).


Figure 27 - Devices with iron cores.


Figure 28 - Magnetic flux lines cannot be insulated.


Figure 29 - Non-magnetized and magnetized material.


Figure 30 - Magnetic flux lines surrounding a conductor.


Figure 31 - Conductor formed into a coil to make an electromagnet.


Figure 32 - Increasing current increases magnetic strength.


Figure 33 - Lightning shows the effects of voltage.


Figure 34 - Battery terminals labelled + (positive) and – (negative).


Figure 35 - Electromagnetic induction. (Courtesy Toyota Canada Inc.)


Figure 36 - Pyrometer and sensor.


Figure 37 - Knock sensor installed in an engine block.


Figure 38 - Resistance decreases as cross-sectional area increases.


Figure 39 - As length increases, resistance increases.


Table 2 - Resistance of a conductor 100 m long with a 1 mm2 cross-sectional area at 20C.

Material Resistance

Silver 1.5

Copper 1.75

Gold 2.2

Aluminum 2.86

Tungsten 5.48

Platinum 9.91

Steel 15

Nichrome 104

Cast iron 60 to 80 depending upon the carbon content


Figure 40 - Diagram showing conventional theory of current direction.


Figure 41 - Electron flow from a battery through a bulb.


Figure 42 - Two electronic components showing conventional current direction.


Figure 43 - DC current.


Figure 44 - Alternating current.


Table 3 - Applied voltage and resistance.

Device Applied Voltage Resistance Current

60-Watt Light Bulb 120 V 240 0.5 A

Headlamp 12 V 3 4.0 A

Starter Motor 9 V 0.064 140.0 A

Dome Lamp Bulb 12 V 24 0.5 A

Heater Motor 12 V 0.8 15.0 A

Heater Motor 14.5 V 0.8 18.1 A

Dash Lamp Bulb 12 V 48 0.25 A

Electric Fuel Pump 9 V 1.6 5.62 A

Electric Fuel Pump 14.8 V 1.6 9.25 A


Table 4 - Various things that electric circuits can produce.

Electrical Circuits

Produce Application

Heat Rear window defroster Cigarette lighter

Rotational force Starter motor Power window motor Electric fuel pump Gauges Heater motor Other motors

Linear force Starter solenoid Relays

Sense conditions Engine coolant temperature Throttle position Engine speed Fuel level Vehicle speed

Light Headlamps Dash lights Brake lamps

Current Recharge the battery Operate vehicle electrical circuits


Table 5 - Various ways of producing 2000 watts of power.

Various Ways of Producing 2000 Watts of Power

Component Cranking Volts Amps Watts

12 V Starter 10 200 2000 6 V Starter 5 400 2000

24 V Starter 20 100 2000


Figure 45 - Manually operated switches.


Figure 46 - Pressure switches.


Figure 47 - Relay.


Figure 48 - Transistors.


Figure 49 - Electrical panel containing circuit protection devices and relays.


Figure 50 - Fuses.


Figure 51 - Circuit with blown fuse.


CAUTION

Never replace a defective fuse with a fuse with a larger ampere rating. Installing a larger ampere rated fuse may cause circuit conductor and component overheating and damage.


Figure 52 - Fuses and the amperage of each fuse.


Figure 53 - Cycling circuit breaker.


NOTE

Always replace a circuit breaker with one of the same ampere rating. Repair the cause of the excessive current flow in the circuit before replacing the defective circuit breaker.


Figure 54 - Circuit breakers.


Figure 55 - Fusible link.


Figure 56


Figure 57


Figure 58

Documents

Electrical Fundamentals Parts Technician First Period Material Identification and Calculations 270103e