How to replace a fluorescent tube with LED: Step-by-step guide

Replacing a fluorescent tube with an LED tube is a simple process, provided the installation is adapted to the type of luminaire and the tube model. In most cases, you only need to remove the fluorescent tube, eliminate the starter and ballast, and adapt the installation. Here you will see how to do it step by step according to your type of luminaire.

What you should know before replacing a fluorescent tube

Before starting, it is important to understand that replacing a fluorescent tube with LED is not always a direct replacement. Fluorescent tubes operate with a starter and ballast, while LED tubes, depending on the model, may operate on direct power supply.

This means that, in most cases, you will have to remove these components so that the installation works correctly.

❝ You are not just changing the tube, you are adapting the system so that it works with LED technology.❞

Advantages of switching to LED tubes

Energy savings: they consume less electricity and eliminate ballast losses.
Longer service life: they last longer and reduce maintenance.
Instant start: no flickering or waiting time.
Mercury-free: a safer and more environmentally friendly option.

What type of installation you have (and how it affects the replacement)

The process for replacing a fluorescent tube with LED depends on the type of luminaire. In general, there are two ways to do it:

Installation with ballast and starter bypass

In this type of installation, it is necessary to remove or bypass the ballast and starter in order to connect the LED tube correctly. Afterwards, the wiring is adapted according to the manufacturer's diagram.

Direct installation according to the tube's power supply type

Once the above components have been bypassed, the LED tube can be connected with single-end or double-end power input, depending on the model. This difference determines how the live and neutral conductors must be connected in the following steps.

Depending on the model, the LED tube may require a single-end or double-end connection, which will determine the wiring method in the following steps.

Preparation before replacing a fluorescent tube

Before starting the installation, it is important to prepare the area to work safely by carrying out the following:

Power shutoff: switch off the RCD or main breaker to avoid any electrical hazard.
Fixture identification: check whether it has a visible starter or internal ballast.
LED tube inspection: verify the connection type (single-end or double-end) before installation.

Proper preparation prevents errors during the process and makes installation easier in the following steps.

Step by step: replacing a fluorescent tube with an LED tube

Once the installation is prepared, you can carry out the replacement by following this process:

Remove the fluorescent tube: rotate the old tube until it is released from the lampholder and remove it carefully.
Remove the starter and disconnect the ballast, if the model requires it, to adapt the installation to the operation of the LED tube.
Adapt the wiring: leave only the live and neutral conductors available to power the LED tube.
Make the electrical connection: connect according to the type of tube (single-end or double-end), ensuring correct installation.
Install the LED tube: place it in the lampholder and secure it in position.
Restore power and test: switch the power back on and verify that the LED tube operates correctly.

❝ Correct installation not only ensures proper switch-on, it also prevents failures and improves system efficiency. ❞

Types of connection in LED tubes

The connection type of the LED tube is a key point in the installation, as it determines how the wiring must be carried out. Not all models are connected in the same way, so it is important to verify this before installation.

Single-end connection

In this type of tube, the power supply is provided from one side only. Both the live and neutral are connected at the same end of the LED tube, usually indicated on the product itself.

Double-end connection

In this case, the power supply is distributed between both sides of the tube. The live conductor is connected at one end and the neutral at the other, following the usual configuration of many luminaires.

❝ Correctly identifying the connection type prevents installation errors and ensures safe operation. ❞

Equivalency table: which LED tube you need based on your fluorescent tube

Replacements are based on dimensions, but wattage also matters. Here is a quick reference to choose the right LED tube according to the size of your current fluorescent tube.

Fluorescent tube size	Fluorescent wattage (W)	Equivalent LED wattage (W)	Approximate savings
60 cm (T8)	18 W	8-10 W	45-50%
90 cm (T8)	30 W	14-15 W	50-55%
120 cm (T8)	36 W	16-18 W	50-60%
150 cm (T8)	58 W	22-23 W	55-65%

These equivalencies are indicative and correspond to T8 tubes, the most common format in this type of installation. If your fluorescent tube has a different wattage, check the LED tube datasheet to confirm that the luminous flux (lumens) is similar or higher.

Common mistakes when switching to LED tubes

During installation, issues may occur that affect the operation of the LED tube or even cause electrical problems.

One of the most frequent is not removing the ballast or starter, which can cause failures or unnecessary power consumption.
It is also common to make an incorrect connection, especially when it is not taken into account whether the tube operates from one end or both ends.
Another aspect to consider is the compatibility of the LED tube with the existing installation. Choosing an unsuitable model may prevent it from operating correctly or reduce its performance.

Avoiding these mistakes is essential to ensure an efficient and long-lasting installation.

Visual summary: replacing a fluorescent tube with LED step by step

Step	Key action	Common mistakes	Checklist
1. Cut power	Switch off the circuit breaker and verify with a voltage tester that there is no voltage.	Relying only on the wall switch. Not using a tester.	- Circuit breaker switched off - Verified de-energized
2. Remove fluorescent tube	Rotate 90°, remove carefully, and place it in a safe location.	Pulling without rotating. Handling without gloves if it is broken.	- Tube removed without breaking - Take to recycling
3. Remove starter	Turn the starter counterclockwise and remove it.	Leaving it connected "just in case." Not deciding between the quick or efficient option.	- Starter removed - Empty starter socket
4. Remove ballast	Disconnect the wires and remove the metal housing.	Leaving the ballast connected (it still consumes power). Not identifying the wires correctly.	- Wires disconnected - Ballast removed
5. Connect mains directly	Option A (2 ends): live on one side, neutral on the other end. Option B (1 end): live and neutral on the same side.	Not checking the tube label. Loose, uninsulated connections.	- Connection type verified - Connections secure and insulated
6. Install LED tube	Insert it, rotate 90°, and verify that it is firmly seated.	Forcing it if it does not fit. Installing a single-ended tube in the wrong position.	- Tube properly inserted - Correct orientation
7. Verify operation	Restore power, switch it on, and observe.	Not checking before closing the luminaire. Mistaking a defective tube for a poor connection.	- Instant start-up - No flicker or buzzing