Electric Wiring

Conductor A material that allows electricity to move readily and offers low resistance Example: copper, aluminum and water

Insulator A material that will not conduct electricity Example: rubber and plastic

Wire Copper is one of the best conductors of electricity

Wire Aluminum wire has to be one size larger to carry same amount of current

Copper Wire Copper wire is preferred, but if aluminum wire is used, one size larger wire must be used to carry the same electrical current.

Copper Wire Example: go from a size 10 copper to a size 8 aluminum Remember: smaller number, larger wire

Romex™ Most wiring used in residential construction is this type

Wire Size is measured in gauge The smaller the gauge number, the larger the wire

Wire Kinds of wire include solid or stranded and copper or aluminum

TW Thermoplastic that is water resistant

TW TW outdoor is used to provide service in areas that have moisture

NM Cable ______ cable is installed inside buildings

NM Non metallic sheathed cable (vinyl or plastic)

Romex™ Non-metallic sheathed cable commonly called Romex ™ has copper wire covered with paper and vinyl for insulation.

UF _____ cable is buried underground as feeder wire

Hot Wire Usually black or red

Neutral Usually white

Ground Wire Usually bare (no insulation) or green

BRASS SCREW Black Wire connects to the_______ Screw

Silver Screw The white wire is attached to the _________ screw.

Green Screw The bare wire is attached to the _______ screw

Clockwise The wire should be looped ________ around the screw.

Types of Wire Indoor types Outdoor types

Indoor Wire T is thermoplastic used for dry locations indoors TW is moisture resistant thermoplastic for indoor dry or wet areas

Indoor Wire RHW is rubber and is heat and moisture resistant and is used for large appliances or service entrance in both wet and dry locations

Outdoor Wire UF is underground feeder wire used for underground service and can be buried directly in soil, but not in concrete

Outdoor Wire USE is unarmored service entrance cables used to bring service into the building

Outdoor Wire ASE is armored service entrance used to bring service into a building

Conduit Provides mechanical protection for wires and may be flexible or non-flexible and metal or plastic depending on NEC Code requirement

Electrical Boxes Outlet, Junction, and Switch Boxes are electrical boxes used anywhere wires are spliced or connected to a switch, light, or receptacle

Receptacles Duplex receptacle has places or holes to receive two plugs

Receptacles A 15a-240v receptacle has holes to receive one plug

Receptacles Dryer and range receptacles are 240v with holes to receive specific shaped plugs

Receptacles Porcelain receptacles for lights may have only a place for a bulb or they may include a chain for a switch, or they may also include an outlet for a plug

Blank Cover Are used to cover junction boxes

Wall Plate Used to cover switch and receptacle boxes

Connectors Cable connectors and split bolt connectors are used to fit knockouts in boxes and to connect outside wires to entrance wires

Connectors Solderless wire connectors are used to turn wires to make pigtail splices and to insulate the connection or splice in one operation

Other Connectors Include ground clamps, screws and clips, entrance elbow and caps or weather heads, and insulators

Meter Is used to measure the amount of electricity used

Circuit Breaker Is a switching device that automatically opens the circuit when too much current passes through it

Fuse Has a strip of metal in it that melts when too much current passes through it

Installation Procedures

Single Pole Switch Types of single pole switches to install include toggle, rocker arm, push button, and silent depending on use and location

Two Terminal A light fixture has two terminals A single pole switch has two terminals

Three-way Switch A three way switch has three terminals and uses two traveler wires-one red and one black

Four-way Switch A four-way switch has four terminals and can only be installed in between two three-way switches It has four traveler wires

Electrical Boxes Electrical or wiring boxes must be installed at every junction, splice, light, switch or outlet

NEC Codes Certain NEC codes require wires to be inside conduit Thin conduit may be cut with a hack saw or a metal cutter saw

Outdoor Wire Is selected according to use

USE USE outdoor is used to provide mechanical protection where wires enter and leave the ground (soil)

SE and SEU SE and SEU outdoor are used to bring electrical service into a building

Wire Loop The wire loop should be attached to a screw terminal in the same direction the screw turns

Rat Tail Splice Is used inside junction boxes

Western Union Splice Is used where strength of the splice is required

Electric Wiring