If you want to learn about line and load on electrical outlets, this short article will help.
In general, the incoming power wires are known as the line side of an outlet. And the outgoing power wires are known as the load side. Often, line wires are located at the bottom of the outlet, and the load wires are located at the top of the outlet. However, you can always test with a voltage tester if unsure.
Read the below article to learn more about line and load on an outlet.
What is Line and Load?
You might be planning to replace a light switch in your home. Or you might be preparing for a complete panel and outlet repair. Either way, identifying line and load connections is vital.
Line Wire

The main line wire in your home comes from the utility company and connects to your main distribution panel. From there, the line wire runs to all the outlets and switches. The Line wire can be described as the incoming power line.
Load Wire

After power reaches an outlet, that outlet sends a wire to the appliance or circuit—this wire, known as the load wire, is responsible for feeding electricity to the circuits. A load wire can be described as an outgoing power line.
How Do the Line and Load Wires Work in Simple Light Bulb Circuit?
Understanding the line and load wires with a simple light bulb circuit is an excellent way to grasp the terms of line load. Here is what happens in a light bulb circuit.
Line wires carry electricity from the main distribution panel to the light switch. Then, the load wire carries electricity from the switch to the light bulb.
We can apply the same concept to the electrical outlet. The Line wire carries electricity to the outlet from the main panel. Load wire carries electricity from the outlet to the particular circuit.
How to Identify Line and Load Wires?
If you can identify the line and load wires inside of an outlet or switch, it will make repairs much easier. Hence, here are two different ways to identify them.
Position of the Wires
This is the easiest method to identify line and load wires. First, take a screwdriver and remove the outlet’s outer cover. Now you can see the wires. The line wires will be at the bottom of the outlet. And load wires will be at the top of the outlet.
However, some electricians might reverse this format. If you suspect such a thing, follow the next method.
Use a Voltage Tester

Using a voltage tester will clear all doubt regarding line and load wires.
- Remove the outlet’s outer cover.
- Switch off the outlet.
- Check the bottom and top wires with the voltage tester.
Because the switch is off, the voltage tester will activate when it touches the line wire. The tester won’t show any response to the load wires.
References
Everyday Home Repairs