If you have an electrical outlet that doesn’t work, it’s important to test it. This can help you determine if it needs to be replaced.
One safe way to do this is to use a multimeter. This small hand-held device can tell you if an outlet is properly grounded and the polarization of its wires is correct.
1. Use a Voltmeter
The easiest way to test your electrical outlets and switches is with a voltmeter. This is a small hand-held device that allows you to measure a variety of electrical measurements, including voltage, ohms and amps.
You can find these in digital and analog versions. Digital voltmeters offer automatic measurement and can even show you a digital readout of the current being measured.
To use a voltmeter, you should first set it to the correct unit. This is important to avoid a dangerous and potentially blown fuse.
Once the multimeter is set to volts, you should insert one red and one black probe into each of the slots on your outlet. You should get a reading between 110 and 120 volts on the multimeter if the outlet is working properly.
If your meter doesn’t give you a number that matches the voltage of your outlet, it’s likely that you have reversed polarity or that your outlet is grounded incorrectly. To check for this, hold the black lead in the U-shaped ground slot on your outlet and insert the red probe into the wider neutral slot.
When performing these tests on live outlets, make sure to hold both meter probes in the same hand to prevent shock from passing through your body. You should also never allow the metal parts of the meter probes to brush each other. This could cause a dangerous short circuit that could kill you or others in the home.
2. Use a Multimeter
When you want to measure voltage, current, and resistance in a circuit or device, a multimeter is the tool of choice. These handy devices are easy to use and provide a range of different measurement options.
They also help you test your home’s electrical outlets and switches in a safe way. However, you need to ensure that your meter is properly connected before you begin testing.
A multimeter is a portable tool that lets you measure voltage, current, and resistance in varying ranges. It can be a great asset to any homeowner who wants to get the most out of their home’s wiring.
The basic unit of a multimeter is the meter itself, which comes with two probes. The black one plugs into the COM (common) port, while the red one goes into the mAVO (measurement of volts and resistance) port.
Once you have the probes plugged in, turn on your multimeter and set the selection knob to volts AC. Most do-it-yourselfers will want to select the AC volts option.
Once you have done that, place the red multimeter probe into the small hot slot on the outlet and the black probe into the larger neutral slot. If the reading is below 110V, the outlet is likely faulty and should be repaired or replaced. If it reads above 120V, the outlet is probably working correctly and you can move on to the next step in your inspection.
3. Use a Volt Detector
Voltage detectors are non-contact voltage testers that safely tell you if there is an electrical current without making contact with live wires or components. They work by sensing the alternating electric field that is generated when an AC voltage is applied to the wire.
To test an outlet, insert the tip of a non-contact voltage detector in both straight slots on the receptacle. If the tester flashes, beeps or both flash and beep, you know there is a live voltage.
Alternatively, you can touch the tip of the detector to a light switch screw terminal. If the switch is turned on, the non-contact voltage detector will beep or flash.
The same goes for a circuit breaker panel. Just make sure to hold both of the meter probes in the same hand, so an electrical shock doesn’t travel through your body while you’re testing.
Voltage detectors aren’t as accurate as multimeters, and they can pick up interference from other electrical equipment, people or even ghosts. However, they can still be useful for detecting whether or not an outlet is live and if a light is working properly. You can find many different types of voltage detectors at Grainger, including battery-operated options that can be used indoors and out.
4. Use a Hot Wire Tester
A hot wire tester, also known as a non-contact voltage detector, is an inexpensive and safe way to test an outlet or switch. It detects voltage without touching exposed wires and will chirp and flash when current is detected.
To use a hot wire tester, insert its tip into the slots of an electrical receptacle or light socket. If there is live electricity, the tester will illuminate and chirp continuously, telling you that the circuit is intact.
If the tester doesn’t show a chirp or flash, you should re-test it to make sure that the hot wire is dead. If the tester beeps, however, it means that the hot wire is live and needs to be disconnected and re-wired.
Another safe and easy way to test an electrical outlet or switch is with a multimeter. Simply insert the red lead into one of the vertical holes in the outlet, and the black lead into the other hole. If you get a reading of 100 to 120 volts, that means that there is a live wire in the outlet.
5. Use a Ground Tester
If you are having problems with your electrical outlets and switches, it might be a good idea to use a ground tester. This is an inexpensive tool that can test your electrical outlets and switches for power, reversed polarity, open circuits or missing grounding.
To use a ground tester, you need a multimeter with two probes (one red and one black). The red probe goes into the live outlet port, the black into the neutral port. Then, you move the black probe to the ground (U-shaped) outlet port.
Next, you need a ground wire or grounding cable. This should be a copper wire that’s at least 3CM long, without any insulation or covering. Then, you need to insert the grounding wire or cable into both the live and neutral outlet ports on your wall.
Then, you need to measure the voltage between these two wires. If the reading is lower than the one you got with the multimeter, then there is a problem with your home’s grounding system. If the voltage reading is higher than the one you got with the multimeter, it means your home’s grounding system is in good shape.
6. Use a Wire Tester
A wire tester, also called a voltage detector, can be used to check whether electrical outlets and switches have power. To use it, simply touch the tip of the tester to the small slot on an outlet receptacle or the large slot on a switch.
Modern electrical outlets have three slots: one for hot (positive), one for neutral (negative) and one for ground. The longer slot (left) is the neutral, and the shorter slot (right) is hot.
If you want to test the ground connection of an outlet, use a circuit tester that includes two probes. The red lead goes into the hot slot, and the black lead into the neutral slot.
The tester’s neon test lamp will light when the two wires are live. This confirms that the electricity is running and you have a complete circuit.
You can also use a multimeter to test if an outlet or switch has power. The meter’s dial allows you to select the voltage mode, which is typically alternating current or direct current.
Using these tools is a safe way to test an electrical outlet and switch. Always ensure that the probes are not brushing or touching each other, as this can cause a dangerous short circuit.
7. Use a Light Tester
If you are looking for a safe way to test electrical outlets and switches, a light tester may be right for you. This handy tool can help you determine if an electrical outlet or switch is working and what kind of circuit it controls, per Popular Mechanics.
When used correctly, a light tester can provide an instant, safe and easy-to-read voltage reading (see Figure 1). This makes it ideal for testing receptacles, as the device’s test lead can easily be placed in the receptacle to check whether or not it is energized.
Many light testers feature a specialized probe tip that can be used to easily prick the plastic insulation of an electrical wire without detaching it from the connection. This can be useful for determining when a fuse is bad, identifying hot cables and tracing wiring paths through an electrical harness, according to DIY Network.
Using a test light on a circuit that is not insulated can be dangerous. This is because the test light bulb can ignite if the circuit is energized. Therefore, it is important to use a light tester with a high voltage rating and make sure the exposed metal tips of the leads don’t touch anything you are not testing.