Electricity for the 4-H Scientist Part 7

Credit Points 3

TAKING CARE OF ELECTRIC MOTORS

Through the magic of electric motors, much of our work is done faster and better at lower cost than we could do it without the help of the electric motor. People who use motors and treat them properly have much more time for other work and for leisure time activities. A 1/4-horsepower motor running quietly and steadily hour after hour will do the work of one man, and operate all day for about 5 cents without tiring. On many jobs it will work without "supervision", turning on and off automatically, as required. It does this on water pumps, in heating and cooling units, and on fans and similar appliances.

All that a motor needs to do its work is electricity and a little care.

Let's see what you can do to give proper care to motors in your home and on your farm.

You'll Need

A light oil (SAE 10) for motors of less than one horsepower and a slightly heavier oil (SAE 20) for larger motors. See if you need grease for cups which may be on large motors. If so, be sure you use ball-bearing grease and not ordinary cup grease. Cotton waste or clean rags will be needed for wiping off the motors, and a tire pump or vacuum cleaner for blowing out the dust or dirt.

[Ill.u.s.tration: Some motors have instructions for oiling on the name-plate.]

WHAT TO DO

1. First, make a list of all the electric motors that work for your home. You may wish to make a separate list for your farm buildings.

You'll probably be surprised at how many there are. Don't forget the sewing machine, the refrigerator, the freezer, the vacuum cleaner and other small but important motors. Don't touch any motor that is running.

Disconnect them before you touch them.

2. Make a motor service chart with columns headed: Use, Location, Horsepower, Volts, Amperes, Service Required, Date Serviced and What was Done. (See sample) Then list all the motors that require any servicing.

Some will have the instructions on the motor or appliance; the instruction booklet that came with the motor or appliance will also tell what servicing is required.

_Step 1._ Plan the job. Start with the motors in the home. Then you can care for the motors on the farm.

_Step 2._ Be sure that any motor on which you are going to work is disconnected. Then wipe the outside case clean with a cloth. If the motor has openings in the end, use a vacuum cleaner to suck out dust, dirt or chaff. A tire pump may also be used to blow out this dirt. If you use compressed air, be sure the pressure is not high as it may damage wiring inside the motor. Dust-proof motors should be used in dusty or dirty places.

_Step 3._

[Ill.u.s.tration: If there are oil holes, oil according to the manufacturer's instructions.]

If there are no instructions, remember a little oil goes a long way as far as motors are concerned. Motors of less than one horsepower require only 3 or 4 drops (not squirts) of oil every 3 or 4 months if the motor is used frequently. Too much oil can damage the motor. It spoils the insulation.

If there are no oil holes or grease cups on the motor, it is probably lubricated by means of grease sealed in the bearings at the factory, or it may use greaseless bearings, and does not need to be oiled or greased periodically. Indicate on your chart all motors which need periodic care and see that it is given according to schedule.

Wipe away any excess oil or grease. Be sure oil holes are capped or covered.

_Step 4._ Reconnect motor and run for a moment.

_Step 5._ Record on the chart the date you serviced the motor and what was done.

What Did You Learn?

How many motors are there in your home? ______ On the farm? ______

How many motors need regular oiling or grease? ______

How many are less than one-horsepower? ______

SAE Oil ______ is used to oil motors up to 1/2 horsepower. How much oil?______

SAE Oil______ is used for larger motors.

Demonstrations You Can Give

1. Show how to clean a small motor.

2. Explain proper lubrication of motors.

3. Using the chart prepared in this work sheet, give a talk about the motors that work for you-the job each one does, which ones need oil or grease, which need no attention, and why, etc.

4. Use a homemade toy motor to explain "what makes motors run."

5. Show proper way to replace worn cord on a small motor.

For Further Information

Ask your county Extension agent or 4-H leader for more literature on motors. They can help you obtain a film or a speaker such as a power supplier, a local electric dealer, or electrical contractor to discuss motors.

Also visit your public library and see a science teacher for more information on motors.

ELECTRIC MOTORS SERVICE CHART Sample

Use a table like the following to list the motors around your farm and home.

---------------------------------------------------------------------- Motor | Location |H.P.|Volt |Amp |Service |Date Serviced and Use | | | | |Needed |what was done ---------------------------------------------------------------------- Food | Kitchen |1/6 |120 |4.4 |Clean & Oil; |9/1-Cleaned Mixer | | | | |cord needs |w/cloth.

Repair | | | | |repair |Oiled w/#10 Oil; | | | | | |repaired cord ---------------------------------------------------------------------- Tool | Farm |1/4 |120 |5.8 |Clear, oiling; |10/6-Cleaned Grinder | Shop | | | |Have switch |w/vacuum Oiled #10 | | | | |Have switch |oil. 10/20-Had | | | | |repaired |switch repaired ---------------------------------------------------------------------- Pump |Pump |1/3 |120 |7.2 |Oiling, |9/26-Cleaned |house | | | |cleaning |w/tire pump; | | | | | |oiled w/10 oil ----------------------------------------------------------------------

LESSON NO. B-7

Credit Points 4

READING THE ELECTRIC METER

There is no question but what electricity is one of the lowest cost services in the home and on the farm. A few pennies worth of electricity will provide the power to run machines that take the place of a man or of several men working all day. However, we all like to know what things cost.

Sometime you may have to decide between different methods--man, horse, gasoline engine or electric motor power. Then you'll want to know how to figure the cost of electricity, as well as the cost of the original equipment. First of all, you should know how to read an electric meter.