introduction to wiring (days 1,2, and 3)

INTRODUCTION TO WIRING

DAYS 1 AND 2

A. What is Electricity?

1. Electricity is the flow of minute charged particles of energy through conductors, such as wires.

2. What does each color mean?

a. Black: “hot”b. White: Neutral/returnc. Green: ground wire

B. What does that mean????

1. Black: This wire carries electricity away from the power source and to the device receiving power.

2. White: Returns power back to the power source…your breaker box.

a. Once the current reaches the breaker box we have a complete circuit.

3. Ground: a safe alternative pathway for the electricity to return to the power source if at any time an accident were to occur. (can be green or bare)

MAKE A CIRUIT LAB**we discussed circuits in the intro to electricity notes

1. Each group will be given a. 2 D batteriesb. 2 wiresc. One bulb (from a flashlight)d. Tape

2. Students need to make: a. 1 functioning series circuitb. 1 functioning parallel circuit.

C. HOW DOES POWER GET TO MY HOUSE??D. Power Stations: produce the electricity.

1. High Power Lines: transport electricity to a substation at a very high voltage (deadly!!)

2. Transformers convert this energy into 120 and 240 volts for use in the home.

3. Electricity enters home from a transformer to your service panel (outside your home)

4. Your circuit breaker distributes the electricity into your home on individual ciruits.

D. SERVICE PANELS

1. Older homes have fuse boxes instead….

2. These boxes are fed with 240 volts of electricity from a transformer!!!

3. We will not practice installing new breakers for obvious reasons!!!

E. WHAT IS A CIRCUIT BREAKER

1. A circuit breaker is a device that electricity will pass through directly before it is delivered throughout the home.

a. Can be 15, 20, 30, and even 50 amp breakers.

2. Function: to sustain the proper amount of current running into your home for the devices connected on that circuit.

a. Will trip/open when to many amps are being drawn. b. Designed to prevent fires and electrical

injuries/tragedies.

Image of Circuit Breaker

F. What is the purpose of a breaker?

1. A circuit breaker is designed to “trip” or shut itself off when it detects a fault current on the circuit.

1. It is important that we only have the appropriate amount of current running through a circuit to meet our household.

2. On/Off/Tripped: a. Depending on the manufacturer the breaker will either

display an orange/red indicator of will flip somewhere into the off position when tripped.

3. **Think about the name…Ciruit….Breaker…..

G. What to do if a breaker trips

1. Investigate what on that circuit caused the breaker to trip.

a. Is the circuit overloaded (to many items plugged in to the outlet)

b. Did water come in contact with the breaker?c. Is there a wire or wires that have been cut/frayed

by something that causes a short?

H. What wire to choose????

1. Types of wire we will discuss: a. Interior wireb. Direct burial outdoor wirec. 12-2 and 14-2 (indoor and outdoor)

2. Other types we won’t have time to go into detail

a. 12-3: This wire has 3 conductors and a ground….12-2 has only 2 conductors and a ground.

I. Images of Types of Wires

J. What does the gauge of the wire mean??

1. The smaller the gauge number….the thicker the wire.

a. 10 gauge is thicker than 12 gauge….and 12 gauge is thicker than 14.

b. The thicker the wire…the more current it can take without heating up.

i. Most 120 volt household wires are 10, 12, or 14 gauge.

2. On the outside of the cable there is a description of the gauge and the number of conductors.

K. Color coding of wires

1. This is a general rule…but def. not a law to live by!!!

a. 14 gauge wire is generally white (indoor)b. 12 gauge wire is generally yellow (indoor)c. 10 gauge wire is generally orange (indoor)d. MOST outdoor wire is gray….outdoor wire each

wire inside is coated individually…you will see when we practice stripping it!!!!!

i. Why would outdoor wire have more coating??

L. Amperage and Wires

1. Circuit breakers set the limit for how many amps can be used in that circuit.

2. Example: a. If an electrical device on 20 amp breaker is

drawing more than 20 amps of power, the wire may heat up….at that point the breaker will sense a potential dangerous situation and trip.

3. It is very important to use the correct gauge wire!!!

L. Amps and wires (continued)

4. The chart below will illustrate what size wire should be used with each size circuit breaker.

5. Using a 14 gauge wire on a 20 amp breaker may be a recipe for disaster in your home.

a. The wire may overheat…but because the current is less than 20 amps the breaker may not consider the overheating a dangerous situation.

b. The heat may end up causing a short circuit or fire.

M. What is a short circuit?

1. Most short circuits occur when a “hot” wire and a neutral or ground come into contact some unintended way.

a. Most of the current in these cases will continue back to the ground using the neutral wire instead of continuing on its intended path.

b. In this case heat builds up very quickly because the current has very low resistance.

c. A working breaker should sense this fault and trip. d. Most short circuits occur due to faulty wiring or bad

connections!!!

N. AMPS VOLTS AND WATTS

1. Amps: measure the volume of the electricity; or the amount of electrons passing a given point every second.

2. Volts: measures the pressure or the force under which electricity moves.

a. Power companies provide homes with electricity pressure of 120 or 240 volts.

3. Watts: what we use to measure electrical power or the measurement of the total amount of electricity used.

a. Watts= Volts X Amps

Connecting your outlets !!!

1. Your completed outlet must be wired to another persons completed outlet.

a. **you must remove the ground from the outlets. b. Grounds are then “sistered” or twisted together

then put on as one ground screw. i. There will be a demonstration!