The wires are the essential part of a light switch as they carry the electricity to the light bulb.
There are two types of wire: black and white. The white wire is used for lighting, and the black wire is used for other electrical devices, like a fan or radio. But what to do if only two black wires are on a light switch?
We’ll discuss the topic and other related things in this article. Let’s check this out!
Contents
Get to know the light switch
A light switch is a simple device that controls the flow of electricity to electric light. It has two or more metal contacts, called “switches,” which control the connection of the circuit. When you flip a switch, you complete an electric course, allowing electricity to flow through it.
A light switch can have up to three wires. The black wire is always the hot wire, which is the one that carries power to the light. And the white wire is the neutral wire, a return path for electricity. And finally, the green or bare copper wire is a ground wire that provides a safe route for electricity in case of an electrical fault.
Some houses only have two wires on their light switches: black and white. But this isn’t enough to provide electricity safely to your home’s wiring system. So how do you know what wires you need?
If three wires are coming out of your switch box, there are likely two black and one white – one carrying power and one providing safety in case of an electrical fault.
Only two black wires on light switch
The black wires are a safety precaution. In the case of an electrical short or overload, the black wires will be grounded, thus preventing any damage to the breaker panel or circuit.
It is a safety precaution taken in case of an electrical short or overload. The black wires will be grounded and prevent any damage to the breaker panel or circuit if there is an electrical short or overload.
It is a common question that many people ask, but the answer is not as straightforward as it may seem. There are two different types of light switches in the market. One type of switch has a neutral wire, and the other doesn’t.
The first type of switch is called a single-pole switch, which means it only controls one set of lights at a time. This type of switch does not have a neutral wire and only has two black wires. It means that power will be going to one set of lights at all times, and when you want to turn them on or off, you will need to flip this switch on or off.
The second type of light switch is called three-way switches, which control two sets of lights at once with three wires.
What if I have two black wires?
You need to know that there are two possible scenarios for this question about having two black wires.
In the first scenario, you have two black wires, which are longer than the other. If you have a three-wire system in your home, you have both black and white wires connected to the same breaker. It would be best to cut off the black wire to make sure that everything is safe.
In the second scenario, you have two black wires, but they are not connected to anything. In this case, there’s an open circuit somewhere in your house. And it’s better to fix it as soon as possible before there’s another fire or worse.
If you have two black wires, you are using a single-pole breaker. It is not recommended to use this type of breaker in the USA. You should install a double pole breaker instead.
If you have two white wires, you are using a three-way circuit breaker. This type of circuit breaker is not recommended for use in the USA because it does not provide protection for any additional circuits and can overload the circuit.
Which wire is hot if both are black?
The black wires are hot, and the white wires are neutral. You need to wire one of the black wires to the live wire, usually red. The other will be wired to the neutral wire, usually white.
But what if the light switch comes with two black wires? Which one is hot?
There is no way to tell if a wire is hot just by looking at it.
A way to tell if the wire is hot or not is by touching it with your finger. If the wire feels warm, then it’s probably a live wire. But this is dangerous, so I suggest you avoid this method.
The other one of the most crucial electrical engineering skills is identifying which wire is hot if both are black. The best way is by measuring the voltage on a multimeter.
We have to measure the voltage because many things can make a wire seem hot, but when measured with a multimeter, they show up as not being hot.
One example of this would be using an extension cord and plugging one side into an outlet and the other into a radio or lamp and then touching them together. It would seem like they were both hot. But when you measure them with a multimeter, they would show up as not being hot at all.
You can connect the two black wires, and the power will be distributed evenly.
How do you wire a light switch with two black wires?
It is a common question for people who are new to wiring. In this part, you will know the steps to wire a light switch with two black wires.
The black wires are the hot and neutral wires. The hot wire is always on, so it must be connected to the brass screw marked with a “line” or “L.” The neutral wire is off most of the time and has to be connected to the silver screw marked with a “neutral” or “N.”
You should connect the black wire with a white stripe to the silver screw marked with a “line” or “L,” which means it will carry both power and signals.
And this is how to wire that kind of light switch:
First, you will need to determine which of the two black wires is hot and which one is neutral. The hot wire will be marked with a stripe or band on it. In this case, the white wire has a line that indicates it is the hot wire.
Next, you will need to find out what kind of switch you have and attach the wires accordingly.
If your switch has three terminals (the screws on either side), attach one of each color wire to each terminal:
- Black goes to brass-colored screw.
- White goes to silver-colored screw.
- Green or bare copper goes to green-colored screw.
