15 Suggested Demonstratiots
20 Problems with Answers
Imade Eas r
I 2 3
4 5 6
Fig. 1.-The six steps in tying the electrician's knot.
Electricity Made Easy
A. M. PETTIS
Farm Electrification Specialist, Florida Agricultural Extension Service
This circular is written to help adults interested in electricity
and 4-H members enrolled in the 4-H Farm and Home Electric
Program. Some people think of electricity as something mys-
terious, hard to understand, and dangerous to use. There's
nothing hard about electricity-turn these pages and see.
PROBLEM I.-How can a broken plug cap on the wire going
to a radio, lamp, or other appliance be fixed?
First remove the broken plug cap. Use a pocket knife to take
about one-half inch of insulation off the two wires. Trim the
insulation like you would sharpen a pencil, being careful not to
cut or nick the shiny brass wires. Bring the wires through the
bottom of the new plug cap. The plug cap should be made of
hard rubber with a grip so it can be removed easily. Tie an
electrician's knot (underwriter's knot) as shown in Fig. 1.
The purpose of the electrician's knot is to keep the strain from
the screws of the plug cap and keep the wires from pulling out.
The wires go around the cap prongs as shown. The bare brass
wires should be twisted together and then put around the screws
in a clockwise direction (the way a clock's hands turn). This
will make the screws hold the wire firmly when tightened.
PROBLEM II.-How can a worn-out ironing plug be replaced?
Remove the old plug from the wires. Take a new ironing plug
and open it up as shown in Fig. 2. Use a pocket knife to take off
about one-half inch of insulation from the wires, as you did in
Problem I. Put the wires through the spring on the ironing plug.
The bare brass wires are twisted and put around the screws in a
clockwise direction. Then put the ironing plug back together,
making certain the spring is in place.
NOTE.-Ironing cords should be heavy asbestos covered cords
made for this purpose. DO NOT USE LAMP CORDS, as they
are not made for such heavy loads.
U. L. LABEL.-This label stands for Underwriters Labora-
tory, and it will be found on good cords and appliances. This
laboratory tests cords and appliances and will not approve them
unless they are good.
Fig. 2.-An ironing plug, showing details of wiring.
PROBLEM III.-How can I change a fuse that has blown?
Unplug equipment that caused fuse to blow. If the fuse box
has a switch, turn it off. Stand on a dry surface. With dry
hands, unscrew the fuse that is blown (it is usually blackened).
Replace with a new fuse. Use 15 A size for lights and wall outlets
in all rooms except kitchen and dining room. Use 20 A size for
kitchen and dining room wall outlets. Never, under any circum-
stances, put a penny or tinfoil behind a fuse. To do so will likely
cause a fire.
PROBLEM IV.-How can I turn on the electricity when a
circuit breaker has tripped off?
Some houses do not have a fuse box. They have a circuit
breaker box. This is a box with switches on it, and each switch
takes the place of a fuse. If the wiring is overloaded, the switch
will trip off, turning off the electricity.
The first thing to do when a switch has tripped off is to un-
plug the equipment that overloaded the wiring. Any switches
that have been tripped usually will be about halfway between
on and off. Throw switch to off position and then to on position.
The electricity will now be on.
PROBLEM V.-What should I do when the lights go out?
If only part of the lights are out, the trouble is in the home.
If all the lights are out there may be other troubles, so take the
1. Check fuse box or circuit breaker box for trouble.
2. If no trouble there, see if your neighbor has electricity.
3. If your neighbor's electricity is off, notify the power sup-
plier, giving all the information.
Caution.-If you find fallen wires, do not touch them! Report
trouble to the power supplier at once.
PROBLEM VI.-How can I read my own electric meter?
There are two types of electric meters, the speedometer dial
and the pointer dial. At the top in Fig. 3 is a meter with
Fig. 3.-Two types of electric meters.
speedometer dial. It is read just like the speedometer on a car.
The reading shown (Fig. 3) is 2359 KWH. At the bottom is the
face of a meter with pointer dial. When a pointer is between two
numbers always read the lowest number. The reading will be the
four numbers indicated by the pointers. For example, the read-
ing on the meter with pointers (Fig. 3) is 2359 KWH.
PROBLEM VII.-How can I tell how much electricity we use
in a month?
Read your meter, then read it again a month later. Subtract
the first reading from the second. The answer is the number of
kilowatt hours (KWH) used.
PROBLEM VIII.-We used 276 kilowatt hours (KWH) this
month; how can I figure the bill?
Electric rates vary throughout the State. Obtain a copy of
the rates from your power supplier. Electric rates are set up
in steps so that the more electricity used the cheaper the cost
per KWH. Here is a typical rate:
First 30 KWH @ 7 0 per KWH
Next 50 KWH @ 5 per KWH
Next 120 KWH @ 3% 4 per KWH
Additional KWH @ 2 ( per KWH
If 276 KWH are used in a month and the above rate applies,
here is how to figure it:
30 KWH @ 7 = $ 2.10
50 KWH @ 5 = 2.50
120 KWH @ 3/2 = 4.20
76 KWH @ 2% = 1.90
Total 276 KWH $10.70 Plus Taxes
Some power suppliers give a special low rate for water heaters
or other electric equipment. Every electric bill has a state
utility tax added, and those on city lines may have a city tax
added also. Many power suppliers in Florida add a fuel clause
to the bill, which means that the price of fuel oil at a certain
time in the past determines the base rate. Then each increase
in the cost of fuel oil means a small percentage increase added
to the bill. When the fuel oil price goes back down to normal
this extra charge will cease.
PROBLEM IX.-How much electricity do appliances use?
The amount of electricity (KWH) that an appliance uses de-
pends on the wattage of the equipment and on the hours used.
Remember, any heating appliance (toaster, iron, water heater)
takes more electricity than a light, a small motor or a radio.
Here are some amounts of electricity used by the average
IN THE HOME
Clock ...................... ................. ...... 2 KW H per month
Coffee percolater .------------------............ 5 KWH per month
Fan (household) .........-... ..............- 2 KWH per month
Iron (hand) ............................ ... 5 KWH per month
Ironing machine .. ................... ..... 10 KWH per month
Lighting .. ............................ ....... 20 KW H per month
Radio .. ........-----------.. -------------- 8 KWH per month
Range ....... ................. ---------- 120 KWH per month
Refrigerator ... .------------------------ 35 KWH per month
Sewing machine .................... ......... KWH per month
Toaster ....-------------.-----------... 3 KWH per month
Vacuum cleaner ...................... .......... ......... 2 KW H per month
Washing machine ........................................ 3 KWH per month
Water heater ................................... 240 KWH per month
Water pump .................................. .......... 8- 10 KWH per month
Home freezer ...................... -----. 30-100 KWH per month
ON THE FARM
Brooder ..................... --------- --------- % KWH per chick raised
Cream separator .................................. .. % KWH per 1000 lbs. milk
Electric fence ..----------....... .... 7 KWH per month
Milking machine ................................. 2 KWH per cow per
Poultry house lighting (during season).. 5 KWH per 100 birds per
Utility motor (1/ h.p.) ............................ % KWH per hour of use
W ood saw ........................ ................ .... 2 KW H per cord of wood
PROBLEM X.-If the voltage is 115 and the fuse is size 15A,
what wattage appliances could be plugged in before the fuse
To find total watts that can be plugged in, use the following
Watts = volts x amps
Watts = 115 x 15
Watts = 1,725
Appliances totaling 1,725 watts could be plugged in on this
circuit before the fuse would blow.
PROBLEM XI.-What do the terms volts and amps mean?
In a water system the amount of water flowing in a pipe is
called gallons per hour. In electricity the amount flowing in a
wire is called amperes or amps.
Amp is the electricity flowing in a wire. Fuses are rated in
amps, such as 15 amp or 15A. A 15A fuse would only allow 15
amps to flow before it blows out.
In a water system the pressure in a pipe is measured in pounds.
In electricity the pressure is called volts.
Volt is the electric pressure. Lights and most electric ap-
Amount of water flowing measured
in GALLONS PER HOUR
Fuse or Break
To water pump
To wall plugs (Kitch. a D.R.)
To other wall plugs
Amount of electricity flowing measured in AMPS
Fig. 4.-Measuring electric current is comparable to measuring water flow.
pliances need 115 volts (V). Electric ranges and water heaters
need twice as much, or 230V.
PROBLEM XII.-What is meant by the terms watt and kilo-
There is no term in a water system for power, but in electricity
the term for power is watt.
Watt is the unit of power. To find watts, multiply volts by
amps. 1 watt = 1 volt x 1 amp. Light bulbs and appliances are
rated in watts, to show how much power it takes to use them. A
100-watt bulb uses more power than a 60-watt bulb. Five 100-
watt bulbs use as much power as a 500-watt electric iron.
Kilowatt-a kilowatt is 1,000 watts.
Kilowatt Hour or KWH is a kilowatt used for one hour. Your
electric meter registers in KWH.
PROBLEM XIII.-What is meant by the terms circuit, horse-
power, three-way switch and four-way switch?
Water pressure measured in POUNDS
duplex wall outlet
Electric pressure measured in VOLTS
Fig. 5.-Electric pressure is measured somewhat as water pressure
A Circuit is all of the wiring system controlled by the last
circuit breaker or fuse in the system. In other words, when a
fuse blows or circuit breaker trips (not the main one) all the
outlets, lights, etc., that go dead are on that one circuit.
Horsepower-A horsepower equals 746 watts.
Three-Way Switch-A type of switch used to turn a light off
and on from two points, as at the top and bottom of stairs or at
two doors in a large room. Here is the way these switches are
connected. Note that three-way switches have three connecting
Fig. 6.-With two three-way switches connected as shown, you can turn
on or off a light from either of two places.
If a person wants to turn a light off and on from three places,
he must get a four-way switch in addition to the two three-way
switches shown. This 4-way switch has four connecting term-
inals. It is connected between the two three-way switches.
PROBLEM XIV.-What are wiring symbols?
Wiring symbols are used on house plans instead of writing,
"This is a light," or "this is a switch," etc. Here are some of
the commonly used symbols:
+ Lighting outlet in ceiling
-P 0 P Pull chain light
=, Convenience outlet (wall plug)
m 230 Volt outlet (range,water heater)
S Single pole wall switch
S3 3-way switch
S4 4-way switch
PROBLEM XV.-How can I draw a plan of my house wiring?
First make a floor plan of your house, as shown in Fig. 7.
(Bulletin "Planning the Farmstead Wiring and Lighting" will
be helpful.) Then put in the wiring symbols to show lights,
switches and convenience outlets.
P Porch "
LR- Living Room
U Utility Room
Fig. 7.-Floor plan of house, showing switches, lighting and convenience
PROBLEM XVI.-How can I draw an improved plan of my
Probably everyone's home could use more outlets and switches
and better lighting. Refer to Extension Circular 93, "Planning
Farm Wiring," for helpful rules in planning wiring. Draw floor
plan as before. Then put in all the convenience outlets needed,
the wall switches needed (be sure to place them on the lock side
of doors), and the lights that are needed (indicate fluorescent
lighting where used).
PROBLEM XVII.-What should I know about the use of
If electric motors are used properly and given care they will
do useful work for many years. Follow these rules:
1. Do not overload a motor-it will get hot and may "burn
out" if overloaded very long.
2. Oiling Motors.-Many motors are ruined every year be-
cause of oil-either too much oil or too little oil. Use a small
amount of oil at regular intervals instead of a lot of oil once a
year. The time between oilings depends on the amount a motor
is used. To determine need for oil see how hard the motor is to
turn and how long it "coasts" after switch is off and load is re-
moved. Use oil made for motors or oil made for car engines.
Do not use sewing machine oil, as it is not made for the heat in an
3. Don't let a motor get too hot. Motors are supposed to warm
up when running. If you can hold your hand on motor, it is not
too hot. If you can't hold your hand on it, it is too hot and you
should turn it off because it will burn up if you don't.
4. Use good wiring to a motor. Small wires and long ex-
tension cords cause voltage drop. This will cause the motor to
have much less power and it will probably heat up or burn out.
Plug 115V motors into convenience outlets, not into drop lights
or extension cords.
5. Ground all motors that are located in a permanent place,
such as water pumps and other farm equipment. Attach one
end of a wire to the frame of the motor and the other end to a
ground stake or pipe.
6. Protect all electric motors against rain, moisture, dust and
7. A small portable motor is useful for operating several
pieces of equipment. Obtain leaflet, "The Small Portable Motor."
8. Watch for smoking, overheating, excessive sparking at
brushes, and hum. These are danger signals. If any of them
occur, turn off the motor and see the repair department of a
dependable electric dealer.
PROBLEM XVIII.-How can I solder wires?
An electric soldering iron is handier and easier to use than
other types of irons. After obtaining a soldering iron, obtain
resin paste and a roll of solder. Use resin core solder instead of
acid core, as the latter will cause corrosion.
When the bare wires have been twisted together, apply paste
to the joint. Place the hot iron flat against the joint and hold
until the joint is hot enough to melt the solder. Apply the
solder to the joint (not fo the iron) until it flows freely through-
out the joint. Iron must be hot to do a good job. (Use a flat
file to clean soldering iron, then tin iron before using).
PROBLEM XIX.-How can two wires be spliced (tied) to-
Use pocket knife to remove 11/2 inches of insulation from end
of each wire, as done in Problem I. Put wires side by side and
twist bare wires as shown to make a pig-tail splice. Solder wires
Fig. 8.-An approved way of splicing electric wires.
Tape the wires after they are soldered. In taping wires use
rubber tape first, as this keeps moisture out. Bring the rubber
tape around the wire and stick tape against tape. Then continue
wrapping splice like a sore finger until completely covered.
Next take friction tape and wrap over the rubber tape in the
same way. The friction tape is tough and it protects the rubber
tape from being damaged.
PROBLEM XX.-What are some safe practices in using elec-
Always follow these rules:
1. Electricity and water do not mix. Never touch anything
electrical when feet or hands are wet.
2. If pull-chain switches are located near plumbing (for ex-
ample in the bathroom or kitchen), fasten an insulating link or
a string to the pull-chain. This reduces the danger of receiving
3. To keep a washing machine from "biting" or shocking, do
the following: Fasten a piece of wire, either bare or insulated
(with insulation removed at both ends), under a metal screw of
the machine. The base of the leg is a good place to fasten one
end of the bare wire. Fasten the other end with a clamp to a
cold water pipe that goes in the ground. This grounds the
equipment and keeps it from causing shock.
4. Do not work on wiring until the electricity is turned off.
5. Unplug an appliance before working on it.
6. Always replace blown fuse with another fuse of the right
size. Never-under any circumstances-place a penny behind
a blown fuse. To do so will likely cause a fire.
7. Always tape or replace bare wires that might cause shock.
8. If a tree or other object is on the electric line, do not at-
tempt to move it until repair crews arrive. Notify the power
9. Always avoid fallen wires and warn others who might en-
counter these wires.
10. When a person is overcome by electric shock, give arti-
ficial respiration if needed. Send for medical help.
SOME SUGGESTED DEMONSTRATIONS
1. A. Obtain a screw-type fuse that has blown and several
good fuses of different ratings. Explain how to change a fuse.
Stress importance of putting a fuse in the fuse box instead of a
penny behind the fuse.
B. Tell how easy it is to reset a circuit breaker that has been
tripped. Mention that appliance that caused breaker to trip
must be unplugged before breaker is reset.
2. Teach groups to tie the electrician's knot. Pass out pieces
of wire to the audience so they can tie the knot while you show
3. Show how to put a plug cap on a lamp cord or an extension
4. Show how to put an ironing plug on the ironing cord. Be
sure to use asbestos covered heavy ironing cord.
5. Explain the following electrical terms:
A. Volt F. Circuit
B. Amp G. Horsepower
C. Watt H. Three-way switch
D. Kilowatt I. Four-way switch
E. KWH (kilowatt hour)
6. Using a dummy meter face or a drawing on cardboard or
the blackboard, show how to read both types of meters.
7. Using a copy of your power supplier's electric rate, show
how to figure an electric bill. A blackboard or charts will be
8. Explain that the amount of electricity used by an appliance
in a month depends on the wattage of the appliance and the
hours used. Make a chart showing amounts of electricity used
by farm and home equipment.
9. Obtain two three-way switches and wire them on a board
to control a light. Use a chart to explain how the switches work.
10. Explain wiring symbols used on house plans. A black-
board or chart will be helpful.
11. Use a blackboard or charts to show a house plan with the
wall outlets, switches and lighting you would recommend. Tell
why wiring should be planned for future uses.
12. Show how to solder wires. Use wires, an electric solder-
ing iron, resin core solder, and resin paste to demonstrate how
to solder wires.
13. Show the right way to splice two wires together. Solder
the wires; then tape the wires, using rubber tape first, then
14. Present helpful information on electric motors. If pos-
sible use one or more motors in this demonstration. A black-
board or charts will be helpful.
15. Use blackboard or charts to present safe practices in
HELPFUL TOOLS FOR ELECTRICAL WORK
Pliars (electrician's side-cutter type)
Screwdrivers (several sizes)
Electric soldering iron
Resin core solder
Tester or test lamp
COOPERATIVE EXTENSION WORK IN
AGRICULTURE AND HOME ECONOMICS
(Acts of May 8 and June 30, 1914)
AGRICULTURAL EXTENSION SERVICE, UNIVERSITY OF FLORIDA
FLORIDA STATE UNIVERSITY
AND UNITED STATES DEPARTMENT OF AGRICULTURE
H. G. CLAYTON, DIRECTOR