How to Bypass a Metal Halide Ballast? – A Detailed Guide


Written by

Thomas Carter



Marcos E. Williamson

how to bypass a ballast

Metal halide lighting is widely used in indoor and outdoor settings due to its brightness. However, many people choose to replace it with LED lighting, which has a longer lifespan and offers better energy-saving benefits.

If you are also looking to switch out metal halide lights for LED lights, you will need to know how to bypass metal halide ballast. In this blog post, we will guide you through just that! Additionally, we will provide information on safety precautions and troubleshooting, so you can carry out a successful replacement.

Bypassing a Metal Halide Ballast: Step-by-step Guide

Certain brands provide a ballast bypass diagram for customers to refer to, such as the one below. But if yours do not come with a guide, this guide here can help.

What to Prepare

You will need a screwdriver, wire strippers, wire connectors, and new LED lights to replace the old metal halide bulbs.

Safety Precautions Before Bypassing a Metal Halide Ballast

1. Turning off the Power


Before bypassing the ballast, turn off the power to the lighting circuit. This will prevent electrocution and other accidents.

2. Checking for Voltage


Check the voltage of the circuit to ensure that there is no electricity flowing. Use a voltage tester or a multimeter to check the circuit.

3. Wearing Protective Gear


Wear protective gear like gloves, safety glasses, and closed-toe shoes to protect yourself from possible accidents or injuries during the ballast removal and bypass process.

What to Do

If you are looking to replace metal halide with LED, bypassing a ballast is a necessary step. Here are the steps you need to take to get the job done.

Step 1: Gain Access to the Ballast


To start, navigate to the ballast and remove the cover. Depending on the type of cover you have, you might need to enlist the help of your screwdriver.

Step 2: Cut the Wires


Locate the wires that run from the lamp holder to the ballast and cut them with wire strippers; these include the hot, neutral, and socket lead wires.

Then, using the same strippers, bare the other cables to create clean, exposed ends. Repeat this process for each wire.

Step 3: Remove the Ballast


Detach the ballast from its position and set it aside. You will not have to rewire ballast in the next step, since this component is not necessary if you are converting metal halide to LED.

Step 4: Connect the Wires


After you remove ballast, go ahead and connect the direct wire lines from the LED light to the wires that you just stripped (aka the power cables from your circuit). You should use wire connectors to ensure a secure connection. Then insert your LED lights into their sockets.

Step 5: Test the New Connection & Troubleshoot

1. Checking for Proper Connections

Before turning on the power, it is important to double-check your connections. Make sure that you have properly wired the LED lights to your old wires. Any loose or exposed wiring may cause electrical hazards.

2. Turning on the Power and Testing

Turn on the power and test the LED lights to ensure they are working correctly. The new lights should function without any problems. If they fail to do so, double-check your wiring and connections.

Now that you know what to do, you can go ahead and apply the steps to your lighting fixtures. Whether you are bypassing a ballast on 2 bulb fixture or on 4 bulb fixture, you can get the job done with the process above.

3. Common Issues & How to Troubleshoot

  • Wiring Issues

Wiring issues may occur, causing problems like overheating, underperformance, or total system failure. It is crucial to ensure that all wiring connections are tight, secure, and correctly linked to avoid these problems.

– If a wire is frayed, you can use electrical tape to cover the damaged section.

– If a wire is too short, you can add an extension to it using a wire nut or splice connector.

– If a connection is loose, use pliers to tighten it.

Note: Consult a wiring diagram if necessary.

  • Short Circuits

A short circuit is another problem that can occur during the bypassing process. This happens when two wires touch each other that should not.

This can be dangerous and cause damage to your electrical system, so it is essential to ensure that all wiring is done correctly.

Moreover, ensure you’re using the correct socket for your new LEDs. The wrong one can ruin your lights quickly and create a short in the circuit. See if your chosen option requires shunted or non-shunted tombstones and adjust accordingly.

Benefits of Bypassing a Metal Halide Ballast


1. Energy Savings

Bypassing a metal halide ballast can lead to significant energy savings. LED lights are more efficient and use less energy than traditional metal halide bulbs. This can translate to lower energy bills and a reduced carbon footprint.

2. Improved Lighting Quality

LED lights offer improved lighting quality compared to metal halide bulbs. LED lights offer a brighter and more consistent light, making them ideal for commercial spaces and outdoor areas.

3. Longer Lifespan with LED Lighting

LED lights have a longer lifespan than metal halide bulbs. By bypassing the ballast and installing LED lights, you will save money on replacement bulbs and maintenance costs. Additionally, LED lights are more durable and can withstand a wider range of temperatures, making them ideal for outdoor use.

Frequently Asked Questions (FAQs)


Can you put an LED bulb in a metal halide fixture?

Yes. It is possible to put an LED bulb in a metal halide fixture. However, you need to be careful and get one with the right amount of lumens. For example, if you are replacing 400W metal halide with LED, you will need around 16,000 lumens.

What happens if you bypass a ballast?

Three key benefits of bypassing a metal halide ballast are energy savings, improved lighting quality, and longer service life of lighting.

Do metal halide bulbs require ballast?

Yes. Metal halide lamps require a high voltage to start and a lower voltage to sustain themselves. The ballast manages this process by adjusting the voltage to keep the lamp functioning optimally. Without a metal halide ballast, the lamp will not work properly.

Can you replace metal halide bulbs with LED?

Yes. Many people choose to do this because they want to enjoy the many benefits that LED lights have to offer. They might bypass 2 ballast for LED tube or for led single pin base. But converting to LED lighting is not the only reason why a person might want to bypass a metal halide ballast.

If your ballast is old or damaged, you may need to bypass it and install a new one. This will ensure that your lamp is functioning optimally and producing enough light.


By bypassing a metal halide ballast, you can improve the efficiency, lifespan, and quality of your lighting system. It is important to follow safety precautions and steps in this guide on how to bypass metal halide ballast carefully to ensure a successful conversion.

If you encounter any issues during the process, refer back to the troubleshooting tips.

Apply everything you have read to confidently bypass a metal halide ballast and enjoy the benefits of LED lighting!

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