electrical principles and wiring materials
DESCRIPTION
Electrical Principles and Wiring Materials. Unit #31. Principles of Electricity. Electricity is a form of energy that can produce light, heat, magnetism, chemical changes Resistance: tendency of a material to prevent electrical flow Conductor: if electricity flows easily - PowerPoint PPT PresentationTRANSCRIPT
Electrical Principles and Electrical Principles and Wiring MaterialsWiring Materials
Unit #31Unit #31
Principles of ElectricityPrinciples of Electricity
Electricity is a form of energy that can Electricity is a form of energy that can produce light, heat, magnetism, chemical produce light, heat, magnetism, chemical changeschanges
Resistance: tendency of a material to Resistance: tendency of a material to prevent electrical flowprevent electrical flow
Conductor: if electricity flows easilyConductor: if electricity flows easily Insulator: material that provides great Insulator: material that provides great
resistanceresistance
Amps, Volts, WattsAmps, Volts, Watts
Amperes: measure of the rate of flow of Amperes: measure of the rate of flow of electricity in a conductorelectricity in a conductor
Volts: measure of electrical pressureVolts: measure of electrical pressure Watts: measure of the amount of energy Watts: measure of the amount of energy
or work that can be doneor work that can be done Ohms: measure of electrical resistance Ohms: measure of electrical resistance
to flowto flow
Ohm’s LawOhm’s Law
Ohm = ROhm = R Volts = EVolts = E Amps = IAmps = I Ohm’s Law: E = IROhm’s Law: E = IR
I=E/R I=E/R
R=E/IR=E/I
Electrical SafetyElectrical Safety Shock and FireShock and Fire Never disconnect any safety deviceNever disconnect any safety device Don’t touch electrical items with wet hands Don’t touch electrical items with wet hands
or feetor feet Don’t remove ground plug prongDon’t remove ground plug prong Use GFI in wet areasUse GFI in wet areas Discontinue use of extension cord that feels Discontinue use of extension cord that feels
warmwarm Don’t put extension cords under carpetDon’t put extension cords under carpet
Electrical SafetyElectrical Safety Install wiring according to NECInstall wiring according to NEC
Blown fuse or breaker, determine causeBlown fuse or breaker, determine cause
Don’t replace fuse with larger fuseDon’t replace fuse with larger fuse
Electrical SafetyElectrical Safety Don’t leave heat producing appliances Don’t leave heat producing appliances
unattendedunattended Heaters & lamps away from Heaters & lamps away from
combustiblescombustibles Don’t remove back of TV (30,000v when Don’t remove back of TV (30,000v when
off)off) Electric motors lubricated, free of grease Electric motors lubricated, free of grease
etcetc
Electrical SafetyElectrical Safety
Keep appliances dryKeep appliances dry Don’t use damaged switches, outlets, Don’t use damaged switches, outlets,
fixtures, extension cordsfixtures, extension cords Follow manufacturer’s instructions for Follow manufacturer’s instructions for
installation and use of electrical installation and use of electrical equipmentequipment
The path of ElectricityThe path of Electricity
Service EntranceService Entrance Power from from power companyPower from from power company Transformer: drops volts from 25,000 volts Transformer: drops volts from 25,000 volts
to 240 voltsto 240 volts Service drop: wires etc from transformer to Service drop: wires etc from transformer to
househouse Entrance head: weather-proof at houseEntrance head: weather-proof at house Meter: $$$Meter: $$$ Service Entrance Panel (SEP): box with Service Entrance Panel (SEP): box with
fuses or breakersfuses or breakers
TransformerTransformer
Service DropService Drop
Service Entrance PanelService Entrance Panel
Electric MeterElectric Meter
Kilowatthours: how electricity is soldKilowatthours: how electricity is sold Kilo = 1000Kilo = 1000 Watthour = use of 1 watt for one hourWatthour = use of 1 watt for one hour
100 watt light bulb for 1 hour - 100 100 watt light bulb for 1 hour - 100 watthourswatthours
Kilowatthour = 1000 watts for one hourKilowatthour = 1000 watts for one hour
Electric Meter BoxElectric Meter Box
Branch CircuitsBranch Circuits
usually begin at SEPusually begin at SEP branch out into a variety of placesbranch out into a variety of places only 1 motor or;only 1 motor or; series of outlets or;series of outlets or; series of lightsseries of lights use correct size wire and fuse or use correct size wire and fuse or
breakerbreaker
Branch CircuitsBranch Circuits
Types of CableTypes of Cable
Nonmetallic sheathed cable: copper or Nonmetallic sheathed cable: copper or alluminum wire covered with paper, alluminum wire covered with paper, rubber, or vinyl for insulationrubber, or vinyl for insulation
Armored cable: flexible metal sheath Armored cable: flexible metal sheath with individual wires inside. Wires are with individual wires inside. Wires are insulatedinsulated
Conduit: tubing with individually Conduit: tubing with individually insulated wiresinsulated wires
Sheathed Cable and Armored Sheathed Cable and Armored CableCable
Wire Type and SizeWire Type and Size coppercopper No 14 (14 gauge) = 15 amp circuitsNo 14 (14 gauge) = 15 amp circuits No 12 = 20 ampsNo 12 = 20 amps No 10 = 30 ampsNo 10 = 30 amps aluminum use one size largeraluminum use one size larger lower gauge number = larger wirelower gauge number = larger wire No 8 and larger use bundles of wiresNo 8 and larger use bundles of wires current travels on outer surface of wire, so a current travels on outer surface of wire, so a
bundle of smaller wires can carry morebundle of smaller wires can carry more
Voltage DropVoltage Drop
loss of voltage as it travels along a wireloss of voltage as it travels along a wire lights dim, motors overheatlights dim, motors overheat larger wires have less voltage drop for a larger wires have less voltage drop for a
given amount of currentgiven amount of current longer wire = greater problemlonger wire = greater problem must increase wire size as distance must increase wire size as distance
increasesincreases
Wire IdentificationWire Identification
Type of outer covering, individual wire Type of outer covering, individual wire covering, cable construction, number of covering, cable construction, number of wireswires
Wire type stamped on outer surfaceWire type stamped on outer surface
Wire TypesWire Types
Type T - dry locationsType T - dry locations Type TW - dry or wetType TW - dry or wet THHN - dry, high tempsTHHN - dry, high temps THW and THWN - wet, high tempsTHW and THWN - wet, high temps XHHW - high moisture & heat resistanceXHHW - high moisture & heat resistance UF - direct burial in soil but not concreteUF - direct burial in soil but not concrete
Wire IdentificationWire Identification
Color coded: black, red, & blue = Color coded: black, red, & blue = positive or hot wires which carry current positive or hot wires which carry current to appliancesto appliances
White = neutral wires carry current from White = neutral wires carry current from appliance back to sourceappliance back to source
Green or Bare = ground all metal boxes Green or Bare = ground all metal boxes and appliancesand appliances
Wire IdentificationWire Identification
Wire Size: 12-2 has two strands of No. Wire Size: 12-2 has two strands of No. 12 wire (black & white)12 wire (black & white)
12-2 w/g same, with one green or bare12-2 w/g same, with one green or bare 12-3 has three strands of No. 12 (black, 12-3 has three strands of No. 12 (black,
red, white)red, white) 12-3 w/g same, with green or bare12-3 w/g same, with green or bare
Electrical Tools & Components
Modified By: Jake Muller
Objectives
Identify wiring tools and wiring components.
Wire sizes and Types
American Wire gaugeWire Diameter in inches
180.040303
160.0508214
140.064084
120.08080810
100.10189
80.128496
60.16202
50.18194
40.20431
30.22942
20.25763
10.2893
00.32486
000.3648
Romex Color Codes
•14-gauge is white
• 12-gauge is yellow
•10-gauge is orange
Wire Types
10/ 2 with ground 12/ 3 with ground 14/ 2
Wire types Continued
Electrical Conduit Types
Breaker Box & SID
Recepticles
Light Switch
Single-Pole Switch
Three Way Switch
Light Sockets
Protection Devices
Circuit Protection Devices
GFCI Receptical
GFCI Breaker
Arc Fault Interrupter
Screw Fuses
Knife/Bar Fuses
Common Grounding
Outlet Grounding
Don'ts
Common Tools
Long-Nose Pliers
Diagonal-Cutting Pliers
Crimper
Multipurpose Tool
Wire Strippers
Cable Ripper
Lineman’s pliers
Automatic wire strippers
MultiMeter
Amp Meter
Review Objectives
Identify wiring tools and wiring components.