Question: Why Does My Light Switch Have Two Black Wires?

What if I have two black wires?

Black means hot, white signifies neutral, and green indicates ground.

However, if you need to rewire a light switch or a plug socket, you may occasionally come across two black wires.

It’s essential that you determine which black wire is hot before proceeding..

What are the 3 wires in my light switch?

One three-wire bundle will have two colored wires (black, white) plus one of bare copper. These link the switch to your light fixture. A second bundle (four-wire) should contain three colored wires (black, white, red) and a copper (bare). The wires here connect this local switch to the other in box 1 across the room.

What happens if you connect 2 hot wires?

You either have no voltage difference between the two wires, or you will get hot wires from opposite hot legs and you will end up with a 240 volt dead short. In that case you will trip at least one circuit breaker, or possibly 2. … If you bring two hots to the switch from the same phase, nothing will happen.

Can Reverse polarity cause a fire?

Watch out: Reversed polarity on an electrical outlet is dangerous. If you accidentally reverse these wires the device you plug in to the receptacle may “work” but it is unsafe and risks a short circuit, shock, or fire.

Can you wire a light switch wrong?

If a light switch is wired up wrongly, a short circuit may takes place if you give phase and neutral to the switch terminals. Always connect neutral wire to the one terminal of the light and phase to the one terminal of the switch and off wire to the other terminal of the switch to the light other terminal.

Why are both white and black wires hot?

like the title says both wires (black and white get or turn hot). To answer your question, Yes, that is correct. The reason you are getting 120 volts when the fan/light is on is because the voltage is feeding trough the motor or the light bulb (or both).

What happens if you connect a hot wire to a neutral wire?

If the hot wire comes into contact with both the neutral and the ground, then it will flow through both wires back to the source but as the ground has less resistance more current will flow through it.

How do you wire a light switch with two black wires?

Connect the top screw to the wire that feeds to the light. Connect the bottom screw to the hot wire. When you turn the power back on, and if you want to swap the direction of the switch (as in press down to turn off, or turn on), turn off the power and switch the two black wires.

Why does my light switch have 4 wires?

Since the switch cuts the power on and off, there will be a black wire coming into the switch and a black wire leaving. The whites are normally just connected together with a wire nut and the coppers are connected together with a wire nut or grounded to a metal junction box. So the new switch has four wires.

Why do I have 2 black wires and 2 white wires?

If there is power in both the up and down position of your light switch, than that is the hot power. If the light was fed power first than here is how you connect the wires. Take your black (hot all the time wire) and marrett it onto the white of the opposite cable (that brings hot power down to your switch).

What happens if you wire a light switch backwards?

What happens if you wire a light switch backwards? … The white wire is the neutral and is grounded in the breaker box and runs to the load and not through the switch. If you put a white wire and a black wire on the switch poles the best case is that you get a dead short and you trip the breaker.

Why does a light switch have 3 wires?

A 3-wire NM connects the traveler terminals of the first and second 3-way switch together. Traveler wires are interchangeable on each switch. The common terminal of the second 3-way switch connects to the light fixture(s). The white neutral wires are connected together in each switch box.

How many wires should a ceiling light have?

The two lamp cord wires on many hanging light fixtures are hard to tell apart. However, it’s critical to correctly identify the neutral wire and connect it to the neutral wire(s) in the box.

Which wire is hot when both are black?

The black wire is the “hot” wire, which carries the electricity from the breaker panel into the switch or light source. The white wire is the “neutral” wire, which takes any unused electricity and current and sends them back to the breaker panel.

Does it matter what wire goes where on a light switch?

There should be one wire only under each terminal. One of these will likely be black. The other may be black, red, or white. One of these is the power feed, and one is the switch leg, but the switch terminals are interchangeable, so there is no need to identify which is which.

Is black wire negative?

Negative – The wire for the negative current is black.

Should both black wires be hot?

If it’s 120 volts between the two black wires…. You most likely have a hot and a neutral. Now check voltage between each black wire to ground. Hot to ground will show 120 volts, Neutral to ground should show zero (or close to zero – in a large building it’s not uncommon to have a few volts between ground and neutral).

Which wire is hot when both are same color?

In most modern fixtures the neutral wire will be white and the hot wire is red or black. In some types of fixtures, both wires will be the same color. In this case, the neutral wire is always identified by some means.