Electrical Installation AMI- 17.0. Class Notes. Objectives. 1. AM17.01 Describe materials used in electric wiring. 2. AM17.02 Explain the procedure for installing switches, making common splices, and doing other electrical wiring tasks. I. Materials used in electric wiring
1. AM17.01 Describe materials used in electric wiring.
2. AM17.02 Explain the procedure for installing switches, making common splices, and doing other electrical wiring tasks.
1. Size is measured by gauge.
a. The smaller the gauge number, the larger the wire.
2. Parts of wire
1). Solid or stranded
2). Copper or aluminum.
a). Copper is one of the best conductors of electricity.
b). Aluminum wire has to be one size larger to carry same amount of current.
b. Insulation- protects from shock
1). Made of colored plastic
a. Splice- Joining two wires together
b. Pig-tail- Joining 3 or more wires together
c. Western Union- strong way to join 2 wires
2. Solderless wire connectors (wire nuts) are used to join wires to make and to insulate the connection or splice in one operations.
a. Indoor types
1. T is thermoplastic used for dry locations indoors.
2. TW -thermoplastic for indoor dry or wet areas.
(9) 3. RHW is rubber and is heat and wet areas
a). Used for large appliances
b). Service entrance-power enters building
1. UF is Underground Feeder wire used for underground service and can be buried directly in soil, but not in concrete.
2. USE is Underground Service Entrance that has to have mechanical protection (conduit) where wires enter and leave the ground.
3. SE/SEU is unarmored service entrance cables used to bring service into the building.
4. ASE is Armored Service Entranceused to bring service into a building.
c. Non-metallic sheathed cable commonly called Romex ™
1. Has copper wire covered with paper and vinyl for insulation.
2. Most wiring used in residential construction is this type.
1. May be flexible or non-flexible
2. May be metal or plastic
3. Depending on NEC Code requirements.
C. Electrical boxes used anywhere wires are spliced or connected to a switch, light, receptacle, etc.
1. Outlet, Junction and Switch Boxes
1. Duplex receptacle has places or holes to receive two plugs.
2. 15a-240v receptacle has holes to receive one plug
3. Dryer and range receptacles are 240v with holes to receive specific shaped plugs.
4. Porcelain receptacles for lights may have only a place for a bulb
a. May include a chain for a Switch, or they may also include an outlet for a plug.
1. Single pole has two terminals and controls lights from one location.
2. Three-way has three terminals and controls lights from two locations.
3. Four-way has four terminals and is used in combination with three- way switches to control lights from three or more locations.
F. Blank covers are used to cover junction boxes-protection
G. Wall Plates are used to cover switch and receptacle boxes.
1. Cable connectors and split bolt connectors are used to fit knockouts in boxes and to connect outside wires to entrance wires.
I. Meter is used to measure the amount of electricity used.
J. Circuit breaker is a switching device that automatically opens the circuit when too much current passes through it.
K. Fuse has a strip of metal in it that melts when too much current passes through it.