Really Easy Electrical Tests

 Electrical Tests

The electrical testers shown here are a continuity tester (left), a multimeter (middle), and two circuit testers (right) available at hardware and parts stores. Continuity testers and multimeters require internal batteries.

The Fix-It Club goal is to make home repairs easier. With simple instructions and an inexpensive electrical tester, you can test a wide variety of electrical and electronic devices in your home. For example, you can perform electrical tests during blender repair, washer repair, dryer repair, refrigerator repair, electrical cord repair, coffee maker repair, electric heater repair, holiday light repair, radio repair, vacuum cleaner repair, fuse replacement, when testing batteries and much more. With just a few uses, you can pay for your electrical tester in repair savings.

The three types of electrical testers for consumers are a continuity tester, a circuit tester, and a multimeter (VOM). All are easy to find and operate, typically coming with printed instructions. You'll find a variety of electrical test tools at hardware stores, auto parts stores and large discount stores. Shop around and ask for help. You'll probably keep and use your first electrical test equipment for many years. Here's how to perform easy electrical tests:

Continuity Tester

Electricity needs a continuous path or circuit to flow. It's like a two-lane road from point A to point B and back. If one or both lanes are blocked, traffic — in this case, electricity — stops. A continuity tester is useful for checking electrical cords and wires to make sure they can conduct electricity.

To test for continuity, follow these steps:

  1. Disconnect the cord from the power source (electrical receptacle or outlet).
  2. Turn ON any switches on the device.
  3. Attach the alligator clip to one prong of the cord.
  4. Touch the tip of the continuity tester to the other prong. If there is continuity, the tester will light up. If not, it won't.

 Electrical Tests

A continuity tester can tell you whether electricity can flow through a cord. Wiggling the cord during the test can show if there is an intermittent break in the circuit.

Here's how it works: The continuity tester sends electricity from an internal battery through one cord prong and down the wires. If the light gets electrical current from the other prong it lights up, meaning that the path is good. Otherwise, something, like a broken wire or component, is stopping it. You can remove the cord from the appliance and test each of the two wires separately to see which one doesn't work. If both work, the short is in the appliance itself. You can buy a continuity tester under $10.

A circuit tester is simply a continuity tester without an internal battery. It uses the device's electricity to power it. Be careful using a circuit tester and follow manufacturer's instructions for safety.

Multimeter

A multimeter (also called a volt-ohmmeter or VOM) is another way of testing continuity. It also can measure the amount of alternating current (AC or household current) or direct current (DC or battery current) in a plugged-in or live circuit. It can check voltage, too.

 Electrical Tests

Analog multimeters measuring conductivity/resistance must first be adjusted for a zero reading. Check instructions that come with a new multimeter.

For example, a multimeter can verify that there are about 120 volts in an AC circuit or that a 9-volt battery is fully charged. In addition, a multimeter can check resistance. A continuity tester checks resistance, but answers yes or no. A multimeter checks resistance and reports how many ohms (the measurement of resistance) a circuit carries.

Fix-It Tip

Troubleshooting some devices may not even require that you use a multimeter. Many major appliances have fault codes that you can read and decipher using the owner's manual. You press a button or two, read the resulting code, and look it up for repair instructions. And, if you don't have the original owner's manual nearby, search for it online. Multimeters are relatively inexpensive. The analog unit shown was $10 and the digital multimeter was $20, though you can pay $50 or more for more accurate models. The ones shown here are sufficient for most electrical tests called for in the Fix-It Guides.

You can use a multimeter to test motors, switches, controllers, home appliances and many other electrical gadgets. Specific instructions will come with the multimeter you purchase.

 Electrical Tests

Connect the multimeter’s probes to the device. (Shown is a digital multimeter.)

Here's how to use a multimeter to test an electric appliance:

  1. Disconnect the cord from the power source, except when testing a live circuit.
  2. Plug the test leads in to the multimeter.
  3. Select the function (ACV, DVC, resistance) and the range (maximum reading expected).
  4. Connect the probes to the cord or appliance component.
  5. Interpret the reading. The Fix-It Guides and the device's owner's manual will tell you what to expect — and what to do about it.

 Electrical Tests

The reading with the device on will show some, but not infinite (1), resistance. If it shows infinite, the switch or other internal component is bad (heating element, etc.) and disassembly is required to fix the problem.

Quick Test

Here's a quick test you can perform on any electrical device without disassembling it. Use a multimeter or continuity tester to check the appliance's continuity — ability to pass electricity from one plug prong to the other — when the switch is on. If it passes, the appliance is okay. If not, you'll need to disassemble it further to find the problem.

Now you know how to perform easy electrical tests! Welcome to the Fix-It Club!

--Dan "The Fix-It Man" Ramsey


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