Do you own an analog or digital multimeter but are clueless about how to use it to test an electrical outlet? With our multimeter check outlet guide, you will learn everything you need to know. If wiring the outlets is your greatest concern, we will help.
In short, you can outlet with a multimeter with the following steps. First, adjust your multimeter accordingly to measure voltage. Next, connect the black plug inside the “COM” port and the red plug inside the Omega port. Then, put a probe into the two vertical slots of the electrical outlet. Put red in the small slot and black into the large slot. Expect 110-120 volts reading for a properly operating outlet. No reading means that the outlet’s wiring is faulty or the circuit breaker has tripped.
Advantages of Checking Outlets
- It helps to ensure that the casing is safe.
- It will help you determine if the wiring within the outlet is reversed.
Notable Things
Ensure that you’ve read the instructional manual that came with your digital or analog multimeter. Do not touch the metal prongs to prevent electrocution. Checking the voltage of an electrical outlet is pretty straightforward. While at it, you can confirm if its casing is safe.
Step By Step Guide For Multimeter Tests of Outlet
We’ve adopted a two-method approach for multimeter outlet tests, namely;
- Method One – Checking an Outlet’s Socket Voltage
- Method Two – Checking If the Casing Is Grounded
Let’s jump right in.
Method 1: Checking the Voltage of an Outlet Socket
1. Familiarize yourself with the landscape of the electrical outlet. The modern outlets have three slots – hot, neutral, and ground. The ground one is the rounded half-circle. Neutral is the longer slot on your left, while hot is the shorter slot on your right. Treat each slot with caution because the three wires can accommodate the current. (1)
2. Set your analog or digital multimeter. Adjust your multimeter accordingly to measure voltage. Can you see a wavy line? That’s the alternating current (AC) function. Select it. Here’s a more detailed guide on how to measure voltage with a multimeter.
3. Connect the leads. The black lead’s banana plug (short thick connector) should go inside the connector bearing the label ‘COM.’ Some usually have a negative sign beside them. Next, plug in the red connector bearing the positive (+) sign or Omega, the Greek letter. (2)
4. Measure the outlet’s voltage. With one hand, put a probe into the two vertical slots of the electrical outlet. Put red in the small slot and black into the large slot. Expect 110-120 volts reading for a properly operating outlet. No reading means that the outlet’s wiring is faulty or the circuit breaker has tripped.

Method 2: Checking If the Outlet Is Properly Grounded
Let the red lead remain in the small slot but move the black lead to the ground outlet slot. The volt reading shouldn’t change (between 110 and 120). If the readings change, it is an indication of improper grounding.
While checking if the outlet is properly grounded, you can confirm if the wiring is reversed. Move the red lead into the large slot and the black lead into the small slot. The wiring is reversed if you obtain a reading on your digital multimeter. While this issue may not interfere with simple electrical items such as lamps, it could spell disaster for more sophisticated electronics.
Wrapping Up
Checking the voltage of an outlet, if it’s properly grounded and if the wiring is reversed is important to the safety of a home or business premise. Without engaging, an engineer or electrician, knowing how to do it is a plus. Thankfully, you can do it using your analog multimeter or digital multimeter.
References
(1) current – https://study.com/academy/lesson/what-is-electric-current-definition-unit-types.html
(2) Greek letter – https://www.britannica.com/topic/Greek-alphabet