Extension cords are one of the most resilient electrical components. These power equipments can last for years, provided that you buy premium quality and observe the basic dos and don'ts while using them.
However, even heavy-duty extension cords will develop malfunctions sooner or later. The faults may be due to normal wear, physical stress, or wiring problems.
Before repairing a malfunctioningĀ extension cord, itās best to check if its conductors are still transmitting electrical current normally. The simplest and safest way to do that is by using a multimeter.
Hereās a beginnerās guide to a multimeter and how you can use the device to test your extension cordās functionality.
What Is A Multimeter?
A multimeter is an instrument designed to measure multiple electrical variables. Most of these gadgets can measure electrical current, resistance, and voltage.
Buying a multimeter saves you the cost of investing in a separate ammeter, ohmmeter, and voltmeter. Depending on the instrument, you may be able to measure additional variables like temperature and capacitance.
More About Current, Resistance, and Voltage
In electrical parlance, current refers to the amount of charge that flows through an electrical circuit in unit time. Itās typically measured in amperes.
Heavy-duty extension cords handle electric current better than their lighter-duty counterparts. Most heavy-duty cables have a gauge rating of less than 12, while the converse is true for lighter-duty wires.
An extension cordās gauge denotes the thickness of its conductors, with thicker wires represented by smaller gauge ratings. The larger the conductor diameter, the more efficient it is at transmitting electric current.
AĀ 16 gauge extension cordĀ is an excellent example of a lighter-duty extension cord. Due to the thinner diameter of its conductors, this cable can only handle less power-hungry appliances like lighting fixtures. Thatās in contrast to 12-gauge extension cords, which have thicker diameters and can power heavy-duty equipment like refrigerators.
You may want to studyĀ extension cord gauge chartsĀ thoroughly to understand the interplay between conductor thickness and current transmission.
Voltage measures the pressure that pushes charged electrons as they flow through an electrical circuit. Itās also known as potential difference or electric tension.
Just like current, an extension cordās voltage rating depends on its gauge. A lower extension cord gauge (thicker conductors) translates to higher voltage stability.
Other factors like cable length also impact voltage.
Note that an extension cordās voltage drops with every square foot. Therefore, aĀ 50 foot extension cordĀ would be more reliable for connecting high-voltage equipment than a 100- or 150-foot wire.
Lastly, resistance measures the opposition to current flow in a circuit. Itās also known as impedance, and the opposite is conductance.
How to Use a Multimeter to Test an Extension Cordās Functionality
1. Take the necessary precautions
Like any electrical troubleshooting process, certain precautions are necessary while using a multimeter.
First, ensure the multimeter isnāt damaged in any way. If the surface is broken and you must use it, donāt touch any exposed wires.
Itās also important to wear rubber shoes and insulated gloves before using a multimeter. This prevents your body from becoming a conduit to the current and potentially suffering shocks or electrocution.
Regardless of if youāre wearing safety gloves, keep your hands off a multimeterās metal probe tips. Donāt switch the settings while still connected to the circuit either.
2. Unplug your extension cord
Most extension cords draw power from the wall socket, although some may be connected to other power strips in aĀ daisy chain.
In any case, unplugging the extension cord is important to avoid electrical shocks.
Even if you use theĀ best extension cordĀ with proper insulation, the risks of touching exposed conductors are real. So, itās best to completely unplug the cable from its socket.
3. Adjust the multimeter settings
If youāre using a digital multimeter, youāll need to turn the dial to resistance or ohms.
Ohm is represented by the symbol Ī©. On a multimeter, the symbol may appear on the dial alone or share a position with several other test modes.
The maximum resistance setting can range from as low as 20MĪ© all the way to 20MĪ©, depending on your multimeter's quality.
4. Complete the test
Locate the red and black probes in your multimeter. The red probe goes into the hole in the extension cordās socket end, whereas the black one goes into the round prong on the cableās plug end.
Now, listen out for any beeping sound, which indicates the circuit is complete. The sound is around the same decibels for different extension cord sizes. Therefore, donāt focus much on the volume.
Repeat the steps with the remaining sockets and plugs, keeping your ears out for a beeping sound in each case. If you canāt hear the sound, itās time to replace your extension cord.
Multimeter FAQ
Is a multimeterās efficacy dependent on extension cord size?
The differentĀ extension cord lengthsĀ do not affect a multimeterās performance.
Why isnāt my multimeter working?
Your multimeter doesnāt work commonly because youāre mismatching the probes. Another reason is that youāre using the wrong settings.
Whatās the best way to store a multimeter?
To prolong your multimeterās durability, store it in a clean, cool, and dry place.
Wrap Up
A multimeter is a handy device that should never be missed in a homeownerās toolkit. The instrument is designed to measure various electrical metrics, including current, voltage, and resistance.
However, a multimeterās significance doesnāt stretch beyond troubleshooting extension cord problems. As for major repairs, it would be prudent to engage a licensed electrician.