The line side of an outlet is the side where you are supposed to connect the incoming source power. As for the load side, the power leaves the device or electrical box and goes downstream in the circuit. These terms have different meanings depending on the location of the device in the circuit.
The line wires are also referred to as “incoming” or “upstream” wires while the load wires are known as “outgoing” or “downstream” wires as well. There are some other significant factors as well that separate them from each other. This article will get you covered as you go through it.
Difference Between Line and Load
The terms “line” and “load” have multiple controversial meanings apart from their general definitions. As a matter of fact, these terms are related to the location of the device in the circuit. For example, the “load” wire for a specific outlet becomes the line wire for the next receptacle downstream.
We can differentiate between line and load depending on their normal definitions and their applications in an electrical system.
Definitions of Line and Load
A device that has a “line” and a “load” side is the one that distributes one or more circuits. The “line” side can be called an input, whereas the “load” side can be regarded as “output”. The wires delivering power into the box are called the line wires or upstream wires.
On the contrary, the wires passing power to other devices are described as the load or downstream wires.
Line and Load in Circuits
As implied previously, the terms “line” and “load” are normally used in the context of a single device or electrical box. In terms of switches, “line” is the wire that goes from a current source into a switch. It is upstream of the switched device and always hot.
On the other hand, the “load” is the wire that goes from the switch to the device. It can only be regarded as the “hot” wire if the switch is closed. For receptacles, the line is the wire that runs from the service panel to the device, while the load is the wire that runs from the first to the second device downstream on the circuit.
In simpler terms, you connect the incoming source power to the line side of the outlet. Contrastingly, on the load side, the power leaves the electrical box and goes down the circuit.
For GFCI Outlets
When it comes to Ground Fault Circuit Interrupter (GFCI) outlets, line and load have a different meanings. The terminals for line and load are clearly marked on a GFCI outlet. That is because the outlet contains a breaker that interrupts current upon detecting a current surge.
For a GFCI outlet, the line is the set of wires coming from the breaker panel. On the other hand, the load is the set of wires that feed the outlets if there are any. The connection of the line and load terminals gives GFCI protection for all outlets.
The line and the load wires play a pivotal role in the distribution of electricity in the house. Besides, they are crucial at incorporating the circuit breakers that control and protect the devices from dangerous electrical upsurge. That is why being able to differentiate between them is a basic skill needed before getting involved with them.