How to Change LED Tube Light

While replacing a fluorescent tube light with LED is relatively easy, there are certain things you need to know. The light fixture should be compatible with the LED and you need to know if the LED is ballast compatible or if you have to bypass it.

Furthermore, there are 4 different types of LEDs and you need to use different methods to install them.

Read on more to know how to check the compatibility of an LED with the light fixture, the different types of LEDs, and how to install each of them.

Choosing the Right LED for your Fluorescent Light Fixture

As mentioned, to replace your fluorescent light with an LED light, the LED should be compatible with the existing light fixture. The compatibility is determined by three factors:

Length of the tube

This is a simple and straightforward thing. Your existing fluorescent light fixture should accommodate the length of the LED. It would normally be 4 feet in length, however, it can vary.

Pin size

The distance between the pins where you clamp the LED light is referred to as the pin size. This pin size should be the same as the diameter of the LED light.

Ballast compatible or ballast bypass

This is concerned with the LED tubes and not with the light fixture. There are two types of LEDs – ballast compatible and ballast bypass.

The ballast compatible LEDs are very easy to install. You just have to unscrew the fluorescent bulb and screw the new LED. It is as simple as that.

The ballast bypass LEDs, on the other hand, are comparatively difficult to install. You have to remove the ballast first, and then install the LEDs. The upside of this is that even if the ballast is burned, these LEDs will continue working. Furthermore, removing your ballast will make the LEDs energy efficient.

How to Remove the Ballast?

You can remove the ballast by yourself, however, if you are not good with electrical wires, then it advisable to seek an electrician. If you are comfortable in connecting the wires, then please follow these steps to remove the ballast.

Step 1: Cut the power

This is the first and foremost thing to do while troubleshooting any electrical appliance. It is also advisable to turn off the main switch, just to be extra cautious.

Step 2: Find the ballast

The specific design of the fixture will differ from one model to another. However, in most cases, the ballast will be covered by a casing and located behind the bulb. Remove the casing to access the ballast.

Step 3: Cut the hot and neutral wires

A hot wire that is in red or black color supplies power to the fixture. Along with it, remove the neutral wire that is in white color. You will find these wires adjacent to each other. These are known as input wires.

Step 4: Cut the socket lead wires

Also known as output wires, they are either red or blue-colored. These wires will be located on the other side of the ballast.

Step 5: Remove the ballast

Now, once you have cut the wires, unscrew the ballast slowly and remove it.

Step 6: Connect the input and output wires

You are not done yet. You need to connect the input wire (red or black) from the building to the output wire (red or blue) in the fixture. You can connect them using push-in connectors or wire nuts. Similarly, connect the neutral wires as well.

How to Measure the Pin Size?

The modern fluorescent light fixtures come with either a T5 or T8 pin. The older light fixtures will have T10 or T12 pins. However, you do not have to worry about them because T8 pins are compatible with T10 and T12 pins. All three have the same G13 base.

You can check the pin size using two options,

Option 1: Check the marking on your fluorescent bulb

The ends of the fluorescent bulbs will have markings that denote whether they are T5 or T8. So, remove the fluorescent bulb from its fixture and check for these markings.

If there are no markings in the bulb, do not worry. There is another option.

Option 2: Check the diameter of your fluorescent bulb

T8 tubes have a diameter of 1 inch and T5 tubes have a diameter of 0.625 inches. Any diameter over 1 inch is either T10 or T12. This way, by measuring the diameter of the tube, you can determine the pin size.

Methods to Install LEDs in Fluorescent Light Fixtures

There are four different methods to replace your fluorescent bulb with LEDs. You need to get the respective LED tubes for these methods. They are as follows,

Direct wire or ballast bypass LEDs

This is the most commonly used method to install LEDs in fluorescent light fixtures. Instead of building complex circuits for the ballast to function, you simply have to remove the ballast and then fix the LED to the fixture pins. This method allows LEDs to directly draw current from line voltages.

The installation is very inexpensive and bypassing the ballast saves more electricity. However, connecting the LED directly to the power supply can cause some safety hazards.

T8 electronic ballast compatible LEDs

They are fast becoming popular due to the ease of installation. The installation process is basically a simple plug and play mechanism. These LEDs are designed to work with electronic ballasts. You just have to pull the old tube and fix the new tube to the fixture.

The major drawback is that these tubes are expensive. Moreover, they need an active ballast to be operational. If the ballast burns or fails, the LED will stop working.

Hybrid LEDs

The hybrid tubes have the advantages of both methods. You can directly connect the hybrid tubes to the fixture without bypassing the ballast. If the ballast fails, these tubes will continue to operate.

However, you need to spend a lot of money on buying these tubes and their efficiency is very low.

Universal ballast compatible LEDs

T12 LEDs use magnetic ballasts and T8 LEDs use electronic ballasts. The universal ballast compatible LEDs, as the name suggests, are compatible with both magnetic and electronic ballasts. As for the installation, you only need to remove the old tube and screw this new tube in place.

These LEDs are the most expensive of all LED tubes. Moreover, if there is a problem with the ballast, you need to replace it for the LED to work.

Frequently Asked Questions

1. Do LED lights really save energy?

Yes, LEDs use diode lights that are energy efficient. They consume less energy than incandescent lights and fluorescent bulbs. it is estimated that LED lights consume 75% less energy than incandescent light bulbs.

2. How do you protect your eyes from LED lights?

Excessive exposure to the ‘blue light’ in LEDs can cause irreversible damage to your retina. You can protect your eyes by using computer glasses or anti-reflective glasses that can block the blue light.

3. Can I remove ballast for LED?

It depends on the type of LED. Certain LED lights are capable of working without ballasts while others won’t work without a ballast.

4. Will ballast compatible LED tubes work without a ballast?

No, ballast compatible LED tubes won’t work without a ballast. However, if you purchase hybrid LEDs, they can work with or without a ballast.

5. What are the signs of a bad ballast?

If the ballast is burnt down, a ballast compatible LED will stop working. If you hear a humming sound from the LED or if the LED flickers, then it is a sign that there is something wrong with your ballast. You need to change it immediately.


If you are someone who is not used to troubleshooting electrical circuits, it would be best to go with ballast compatible LEDs. They are very easy to install. Or else you can call an electrician to install the ballast bypass LEDs. If you can spend a little extra, you can opt for hybrid LEDs that can work with or without the ballasts.
Have you tried installing the LED in your light fixture? Did you face any specific difficulties? Share your experience with us using the comments section below.