How to connect a lamp with two black wires (Expert's Guide)

Content

What you need to know about luminaire wires
Why are the lights supplied with two black wires?
Identification of luminaire wires
- Method 1 - Visual Wire Identification
- Method 2 - Use a digital multimeter
Easy 6-Step Guide to Connecting a Light with Two Black Wires
Summing up

Sometimes, instead of a black and white wire, you get two black wires. Whether you are planning to install a new fixture or refurbish an existing fixture, you need to know which one is which.

I've run into this issue on many wiring projects. In electrical circuits, the white wire is the neutral wire and the black wire is the hot wire. The ground wire will be green. When considering lighting fixtures, the above color coding system is not always correct, and incorrect wiring can result in costly damage.

As a general rule, when connecting a luminaire with two black wires, follow these steps.

Turn off the main power of the luminaire.
Take a picture of the old setup.
Correctly identify the wires.
Remove the old lamp.
Install a new lamp.
Check lighting fixture.

You will find more detailed information below.

What you need to know about luminaire wires

We usually don't pay much attention to fixture wires until they need to be replaced or repaired. So you may end up with two black wires when trying to replace a new fixture. However, for each lamp, everything is not so difficult. For example, you will find some fixtures with the correct color coding.

Most lighting fixtures have these wires color-coded.

Black wire - live wire
White wire - neutral wire
Green wire - ground wire

Other than that, you can also find the following options.

You will receive two wires of the same color (black, white or brown).
In some fixtures, you will not find ground wires.
You can see the red wire. These red wires are connected to the light switch.
You may also see yellow or blue wires. These wires are for ceiling fans or XNUMX position switches.

As you can imagine, lighting wires are hard to identify, especially if you have two black wires.

Why are the lights supplied with two black wires?

There are two reasons for this dilemma with the same colored wire.

Someone can turn a lamp into a wired lamp. If so, you will get two wires of the same color. it can be two black wires or white wires.
If you are using a fixture made in another country, it may have two black wires.

The color coding of electrical wires varies by country.

For example, the wire color coding system in the US will not be the same as in China. So that there is no confusion, manufacturers sometimes produce lamps with two black wires.

Identification of luminaire wires

In this section, we'll talk about two methods for identifying lighting fixture wires. The two methods are completely different and I have used them many times successfully throughout my career.

Method 1 - Visual Wire Identification

This is sometimes common with manufacturers... If you have a lighting fixture with two black wires, the smooth black wire is the hot wire.

The ribbed wire is the neutral wire. Sometimes there is a stripe on the neutral wire. This is the easiest and fastest way to identify lighting wires.

Keep in mind: During the visual inspection, be sure to turn off the power.

Method 2 - Use a digital multimeter

In this method, we will use a digital multimeter.

First, set the multimeter to voltage measurement mode. Remember to select AC voltage.

Then connect the black test lead to any ground point. It could be a faucet or a refrigerator. Or connect the black test lead to the ground wire on the fixture.

Next, connect the red probe to the 1st black wire. Then connect the probe to 2^nd black wire. The wire that gives the higher voltage value is the hot wire. The neutral wire shows no voltage on the multimeter. If you can't find a multimeter, use a voltage gauge to check for voltage.

Sometimes the color coding of light switch wires can be confusing. So using a multimeter is a great solution.

Keep in mind: During this method, apply power to the lighting fixture. Also, the lamp must be connected to the wires of the light switch.

Easy 6-Step Guide to Connecting a Light with Two Black Wires

Now you know how to correctly identify lighting fixture wires. So, we can start the process of connecting the lamp.

Things You'll Need

Safety glasses
Digital multimeter or voltage gauge
Several wire nuts
Screwdriver
Electric pliers

Step 1 - Turn off the power

First of all, open the main panel and turn off the power to the luminaire you are about to replace. Find the appropriate circuit breaker and turn it off. Or turn off the main switch.

Step 2 - Take a picture

Then remove the outer housing of the light to expose the wiring. Do not remove the old lamp yet. Take a picture of the exposed wiring with the fixture. It will come in handy when replacing a new lamp. (1)

Step 3 - Define the Wires

Then follow any of the methods from the previous section to identify the lighting wires.

I would recommend using both methods for more security. This will help you identify the wires correctly. If necessary, mark the hot or neutral wire with any electrical tape. (2)

Step 4 - Remove the old fixture

Now loosen the connected wires with a screwdriver and pliers. Then carefully remove the lamp.

Tip: Some wire connections may have wire nuts. If so, remove them smoothly.

Step 5 - Install the New Light

Then take a new light and connect its hot wire to the black wire coming from the light switch. Connect the neutral wire of the lamp to the white wire of the light switch.

Use wire nuts to tighten wires. After that, install the lamp on the ceiling.

Step 6 - Check the fixture

Apply power to the lamp. Then turn on the light switch to check the light fixture.

Summing up

Before replacing or repairing a luminaire, the wires must be correctly identified. Improper wiring may result in electric shock or damage to electrical appliances.

So, try to identify the wires by carefully examining them. If you don't get good results from this, use a multimeter or voltage gauge and follow the steps above. Also, if you are having trouble following the above process, feel free to hire an electrician.

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