Basic House Wiring. Electrical Measurement Terms Amp - measures the rate of flow of electrical...
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Transcript of Basic House Wiring. Electrical Measurement Terms Amp - measures the rate of flow of electrical...
Basic House Wiring
Electrical Measurement Terms
• Amp - measures the rate of flow of electrical current
• Volt - measure of pressure or force pushing electricity
• Ohm - measure of electrical resistance
• Watt - basic measure of electricity (amps x volts = watts)
Other Basic Terms• Ground - connector that runs between a
device or circuit to safely conduct current to earth
• Conductor - device intended to carry electrical current
• Insulator - material that is a poor conductor of electricity; used to prevent electrical flow
• Short circuit - accidental connection between two conductors
• Overload - to run equipment in excess of its normal full load
Where does electricity come from?• 1) Generation
– Nuclear fission - split atoms– Hydro power - moving water– Burning fossil fuels - power plants
• 2) Step-up transformer – Voltage stepped up in transformer to between
69 and 345 thousand volts (sometimes even higher)
• 3) Transmission lines– Electricity travels through wires over long
distances
Where does electricity come from? (continued)
• 4) Step-down transformer– Voltage stepped down in transformer at substation to
between 2000 and 13000 volts• 5) Distribution Lines
– Electricity travels around community (sometimes above ground and sometimes below ground
• 6) Distribution transformer– Steps down voltage to between 120 and 240 volts for
use in business or home• 7) Customer line
– Electricity enters homes or business
Circuit
• Path for electricity– Closed - electricity is allowed to flow– Open - electricity is stopped
• Many circuits within a home
Fuse/Circuit Breaker Boxes
• Each branch circuit is protected by fuses or circuit breakers
• If too much current is used, fuses or breakers will open the circuit – Fuse - if blown needs to be replaced– Circuit breaker - “trips” to open circuit; may be
reset
Voltage
• Two wires carry 120 volts each– 120 used for lights and small appliances
(outlets)
• Two wires combined for 240 volts – 240 volts used for large appliances (oven,
dryer, hot water heaters, air conditioners)
Basic Electrical Tool Kit• Screwdriver• Long-nose pliers (similar to needle nose but has
curved ends)• Lineman’s Pliers• Side Cutters - Diagonal-cutting pliers• Tin Snips• Wire Stripper/Cutter (Multipurpose tool)• Cable Ripper• Fuse Puller• Fish Tape• Conduit Bender
Testers
• Receptacle analyzer
• Voltage tester
• Continuity tester
• Multimeter (has specific settings to test all - voltage, amperage, and resistance)
Basic Electrical Relationship
• Ohm’s Law– I = amperage (the flow of electrons)
– R = resistance (resistance to the flow)
– E (or V) = voltage (force behind electrons)
– E = I x R
E (or V)
I R
Basic Skills for Replacing an Extension Cord End
• Use a wire ripper to slice cable sheathing
• Remove cable sheathing
• Use a wire stripper to remove insulation around each wire
• Make necessary connections– Hook wire clockwise over screws– Twist wire clockwise for wire nuts
Wire Identification
• Black wire - “hot”...electricity is brought to devices through this wire
• White wire - “neutral”...electricity goes back through this wire
• Bare Copper or Green wire - “ground”...safety for all stray electricity
Back
Long Nose Pliers
Back
Lineman’s Pliers
Back
Side Cutters
Back
Tin Snips
Back
Wire Stripper/Cutter
Back
Cable Ripper
Back
Fuse Puller
Back
Fish Tape
Back
Conduit Bender
Back
Receptacle Analyzer
Back
Voltage Tester
Back
Continuity Tester
Back
Multimeter