Electrical Workshop - Quia

Electrical WorkshopModule 1: SafetyPREPARED BYAcademic Services UnitAugust 2012 Applied Technology High Schools, 2012

ATE210 – Electrical WorkshopModule 1: SafetyModule ObjectivesUpon successful completion of this module, students should be ableto:1. Outline safety rules that apply to conditions at homes, labs andworkshops, and jobs.2. Identify electrical hazards and learn how to avoid them.3. Explain the factors that determine the severity of an electricshock.4. Learn how to respond to emergency situations in case ofelectrical hazards.Module Contents:TopicPageNo.1.1Introduction to Electrical Safety31.2Home Safety41.3Outdoor Safety61.4Lab & Workshop Safety71.5Safety and Accident Prevention Signs101.6Introduction to Electricity111.7Electric Shock141.8How to Act in Emergency Situations151.9Class and Lab Activities172Module 1: Safety

ATE210 – Electrical Workshop1.1 Introduction to Electrical SafetyElectricity is a useful and powerful tool in our daily life. Everythingaround us works with electricity such as lamps, TVs, computers,mobile phones and DVD players. Today, electricity has become suchan essential part of our life that it is difficult to imagine life withoutit. Figure 1.1 shows examples of equipment that work on electricity,which demonstrate the importance of electricity in our daily life.Figure 1.1: Importance of electricity in our daily lives.However, electricity is very dangerous. It can cause shock, burn orkill you.Electricity can also damage sensitive devices. Figure 1.2gives examples of the dangers of electricity. This module covers thebasic safety rules and practices that apply at home, outdoor, labsand workshops.Figure 1.1 Dangers of electricityModule 1: Safety3

ATE210 – Electrical Workshop1.2 Home SafetyTo protect your home from electrical risks and hazards, you need tofollow some home safety tips that are illustrated below:DON'T overload plugs as this Never use an electrical appliancein a wet area. This can cause ancan cause electrical fire.electric shock.DON’T pull on the cable to Never allow children to play withremove a plug from the socket. outlets. Inserting conductors inThis can damage the insulation an electrical outlet is dangerousand cause an electric shock or and can cause shock, which canan electrical fire.4kill a person.Module 1: Safety

ATE210 – Electrical Workshoppushed Replace the socket outlet if thecarefully all the way into the plug is loose in the socket or if itshows signs of damage.power points.PlugsshouldbeDON’T make joints in a cable;replace it with one of adequatelength.DON’TSwitchesandpowerpointsshould not be cracked, brokenor loose.let leads from electrical Always use plug protectors toequipment, such as toasters or stop small children from pushingkettles, trail across your cooker things such as keys and pins intotops.Module 1: Safetythe power outlet.5

ATE210 – Electrical Workshop1.3 Outdoor SafetyThere are many outdoor electricity sources that can cause electricityhazards such as high voltage power lines, electricity substations andtransformer boxes. To avoid accidents and protect yourself fromelectrical injuries, follow the next tips:WHILE WORKINGNever bring ladders, long- Never touch the undergroundhandled tools or other items power lines.within 10 feet of an overheadpower line.While PlayingNever play with transformers Neverbecause they carry high voltages airplanesthat can be deadly.6flykitesnearorelectriclines.Module 1: Safetymodelpower

ATE210 – Electrical WorkshopWHILE PLAYING – cont.DON'T play near live DON'T play nearDON'T climb treespower lines. If you see electricity substations.that are neara downed power line, They contain powerfulpower lines. Thisstay as far away as electrical equipmentcan seriouslypossibleinjure you.andkeep that is dangerous.others away.1.4 Labs & Workshops SafetyBefore you can use equipment and machines orattempt practical work in a workshop or a lab,you must understand basic safety rules. Theserules will help keeping you and others safe in the workshop.Following safety rules will also prevent you and others fromaccidents, injuries as well as death. To avoid accidents and injuriesin the workshops and labs, follow the next safety rules andpractices:Before conducting workshop tasks, be familiar with thelocation of:Fire extinguishersModule 1: SafetyFire alarm pullstationsFirst aid kits7

ATE210 – Electrical WorkshopEmergency telephonenumbers.Emergency exits.Smoking, eating or drinkingare not permitted in labsand workshopsKeep the workshop floor dry8Emergency stopbutton.Keep the workshop clean andtidy at all timesKeep your tools and work areaorganizedModule 1: Safety

ATE210 – Electrical WorkshopWear safety shoes while workingReport accidents such as in a workshop. Sandals orspells, burns, cuts or injuries slippers are not allowed into the teacher immediatelyworkshopsDon’t joke or play with yourKeep your lab bench organizedfriends inside the laband free of bags and booksListen Carefully to all instructionsand lab procedures from yourteacher. Ask questions if youaren't sure.Module 1: SafetyAlways use the appropriatepersonal protective devicesand check that they are cleanand in good condition.9

ATE210 – Electrical Workshop1.5 Safety and Accident Prevention SignsWe have seen a number of safety signs that read, “Warning”,“Caution”, or “Danger”. Figure 1. 2 show some common safetyand accident prevention signs and their meanings.RespiratoryProtectionEye ProtectionFootwearprotectionHearingProtectionNo SmokingHandProtectionHard HatProtectionHighlyFlammableHigh VoltageHazardBiologicalHazardNo WalkingPoisonousHazardFigure 1. 2: common safety and accident prevention signs10Module 1: Safety

ATE210 – Electrical Workshop1.6 Introduction to ElectricityHave you ever thought how electricity comes to your house? Electricityis generated from different sources such as power stations, windturbines, water power, solar power and battery power. Figure 1. 3shows the sources of electricity. Figure 1. 4 shows how electricityreaches your home.Figure 1. 3: sources of electricityFigure 1. 4: How electricity comes to your homesModule 1: Safety11

ATE210 – Electrical WorkshopBasic Electrical Terms:Circuit: Complete path of the Current (I): Flow of electrons. Itcurrent. It consists of electricity is measured in amperes (A) by ansource, a conductor, and the Ammeter .output device or load (such as alamp, or a heater).Voltage (V) : is the pressure thatcauses the flow of electric currentin a circuit. It is measured in volts(V) by a Voltmeter.12Resistance (R): Restriction tocurrent flow. It is measured inunits called ohm (Ω) by anOhmmeter.Module 1: Safety

ATE210 – Electrical WorkshopConductors: Materials that allowInsulators: Materials that do notelectric current to flow easily suchallow electric current to flow suchas; metals and water.as; wood, plastic , rubber andpaper.Grounding: A conductive connection from all equipment to the earthwhich acts as a protective measure. It is a safety measure to helpprevent people from accidentally coming in contact with electricalhazards. For example, by connecting the metal frame of therefrigerator to the ground, if the chassis becomes charged for anyreason, the unwanted electricity will travel down the wire and outsafely into the earth; and in the process, trip the circuit-breakerstopping the flow of electricity.Module 1: Safety13

ATE210 – Electrical Workshop1.7 Electric Shock An electrical shock is received when electrical current passesthrough the body. You will get an electrical shock if part of your body completesan electrical circuit by:1. Touching a live wire and the electrical ground as shown inFigure 1. 5.2. Touching a live wire and another wire at a different voltage.Figure 1. 5: how can you get an electric shock?Severity of the shock depends on (see Figure 1. 6) :Path of current through the bodyAmount of current flowing through the body (amps)Duration of the current flow through the bodyFigure 1. 6: factors that determine the severity of electric shock14Module 1: Safety

ATE210 – Electrical Workshop1.8 How to Act in Emergency SituationsDowned WireStay away from allDonottouchdowned wires - even if Get help right away.anything, or anyone,there are no sparks.that is touching adowned wireDowned Wire Touching a VehicleIfyouareaIf you are inside a If you must get out,witness,stayclearvehicle, wait inside for jump without touchingthe ground and the and call for help.help.vehicle at the sametime.Module 1: Safety15

ATE210 – Electrical WorkshopElectrical FireGet help right away.Unplug the faultyappliance to turn offthe power, ifpossible.Never throw wateron an electrical fireElectrical ShockNever touch aperson who is beingshocked.16Unplug the faultyappliance or turn offthe power, ifpossible.Call for helpimmediatelyModule 1: Safety

ATE210 – Electrical Workshop1.9 Class & Lab ActivitiesActivity 1: Indicate the safe and unsafe behavior in thefollowing pictures. Give ReasonsBehaviorModule 1: SafetySafeNot safe17

ATE210 – Electrical WorkshopActivity 2: Sort the following items into conductors andinsulatorsConductorInsulatorMetallic keyCartoon boxPlastic rulerWaterPaper clips18Module 1: Safety

ATE210 – Electrical WorkshopActivity 3: Fill in the following table:TermResistanceVoltageSymbolUnitMeasuring DeviceRvolts (V)CurrentAmmeterActivity 4: Complete following sentences: The severity of the electric shock depends on:1.2.3. List three tips for workshop and lab safety:1.2.3. What should you do if you see a downed wire?1.2.3.Module 1: Safety19

ATE210 – Electrical WorkshopActivity 5: Identify and name the following safety equipment:Activity 6: Write the name of each of signs shown below.20Module 1: Safety

ATE210 – Electrical WorkshopActivity 7: Differentiate between the circuits shown in the figuresbelow by answering the following questions:C ircu it 1R u bberC ircuit 2Meta la) The lamp in circuit 1 is off. Give reasonb)The lamp in circuit 2 is on. Give reasonModule 1: Safety21

ATE210 – Electrical Workshop 14 Module 1: Safety 1.7 Electric Shock An electrical shock is received when electrical current passes through the body. You will get an electrical shock if part of your body completes an electrical circuit by: 1. Touching a live wire and the electrical ground as shown in Figure 1. 5. 2.