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Main Lug Vs Main Breaker – What Are the Differences?

Both main lug and main breaker are considered two of the most important pieces of equipment that are used as load centers. They are both parts of the electrical panel board. The main lug is utilized as a distribution panel and the main breaker is used as a protector against overcurrent.

Today, we are going to discuss many more differences like this between the main lug and the main breaker.

What is a main breaker panel?

The largest breaker panel of the electrical panel is known as the main breaker panel. The main breaker or main circuit breaker panel is used as a shut-off measure on the electrical panel. The main breaker panel is usually situated in the middle of the distribution board.

The main breaker panel is the receiver of the electrical current that comes into the house. The main circuit breaker panel works as a safety measure against power surges and power spikes. 

It can shut off the power flow to the electrical equipment and utilities of the house if it senses a system overload.

The main breaker panel also distributes current down to all the individual circuit breakers as it is the receiver of the current that flows into the house. Without the existence of the main breaker panel, the electricity system of the house will fail to function properly.

What is a main lug panel? What does a main lug do?

The main lug panel does not possess the main breaker. In the main lug panel, the incoming supply cables are not connected to the main breaker as it does not have one. Rather they are connected to the bus bar and the main lugs directly. 

The primary purpose of the main lug panel is to act as the distribution panel.

Other names for the main lug panel include the secondary panel and the downstream panel. The reason behind these names is that the main lug panel is used when the need for a remote panel arises. 

All the slots of the main breaker panel becoming occupied can also call for the need for the main lug panel.

Sometimes the main breaker panel uses the main lug panel as a workshop of some sort. The main lug panel also gets the flow of electricity from the metering equipment of the house.

Main lug vs main breaker – What are the differences?

The main lug panel is used as a sub-panel of the main breaker. The purpose of the main breaker is to control the flow of electricity. The incoming wires of the main lug panel are connected to the main lugs. But on the main breaker panel, the incoming wires are connected directly to the main breaker. 

There are some major differences between the main lug panel and the main breaker panel. Let’s talk about some of them below.

The structure:

The main breaker panel is designed in such a way that it is able to withstand the incoming power of the house. There are many kinds of panels on the electrical board. But the main breaker panel is the most crucial one.

The service wires of the house depend on the main breaker panel heavily in terms of distribution. Two hundred and forty volts of current coming through the service wires flow into the feeding wires via the main breaker panel.

On the other hand, the main lug panel does not have a main breaker in it like the main breaker panel. The incoming wires coming into the main lug panel are connected to the main lugs. 

The main lug panel is designed in such a way that allows it to be used as a distribution panel. The structural difference between the main breaker and the main lug panel is massive.

The purpose:

The purpose of the main breaker panel is clear and simple. It is installed in the electrical panel to control the flow of electricity that comes into the house through the service wires. The main breaker panel acts as a shut-off switch in the electrical system of the house.

If there is an increasing demand for power that is formally known as power surges and power spikes, then the main breaker panel will stop the flow of electricity into your house to protect the electrical system.

The purpose of the main lug panel is to be used as a sub-panel of the main breaker panel.

When the main breaker panel becomes full and can not give space to new circuit breakers, then the main lug panel is installed in the house to be used as a remote panel to decrease the load of the main breaker panel.

Can I use a main lug panel as a main breaker panel?

You can not use a lug panel as the main breaker panel. Because the structure of the main lug panel is different from the structure of the main breaker panel. The purpose of these two panels also differs. 

The main breaker panel is used as a shut-off and distribution system whereas the main lug panel is used as the substation of the main breaker panel.

So a normal main lug panel can not be used as the main breaker panel. The biggest reason behind this is that the main lug panel does not have a main breaker in it. 

You will be required to make some fundamental changes to your existing main lug panel if you want to use it as the main breaker panel. But this altering method is not recommended by the experts. Instead, you should just build a new main breaker panel.

Can I add a main breaker to the main lug panel?

Adding a main breaker to the main lug panel is not recommended. The main breaker works as a shut-off system on the main breaker panel. The main lug panel does not need a main breaker because it is not used as a shut-off system. 

There is also no extra place left on the main lug panel by the manufactures where you can fit the main breaker.

But you can add a main breaker to the main lug panel by using one of the branch breakers. But the size of the main breaker in the main lug panel will need to match the size of the main breaker in the main breaker panel.

Even the size of the main breaker you are trying to install in the main lug panel can be smaller than that of the main breaker panel. But it can not be bigger than the main breaker installed in the main breaker panel.

How to convert the main lug to the main breaker?

It is not technically possible to convert the main lug panel to the main breaker panel. Because each of them is built differently and serves a different purpose. But you can certainly replace the main lug panel with the main breaker panel by following the steps below.

Remove the main lug panel:

First of all, you will need to open your electric box panel and remove the whole lug panel from it. Without removing the main lug panel, you can not replace it with the main breaker panel.

Before starting this process, you need to turn off the existing main breaker of the house to stop the flow of electricity. Because working on an electric box when the flow of electricity is on could be dangerous and life-threatening. 

You can use a voltage tester to become absolutely sure about the flow of the electricity that is absent.

You can remove the main lug panel by unscrewing the bus bars and branch breakers and removing them from the feeding wires.

Install the main breaker panel:

Next, you will have to start the installation process of the main breaker panel. The voltage of the main breaker panel needs to match the voltage of the main lug panel you are trying to replace. 

Because without having the same voltage and size, the installation process can not be done.

You will need to position your main breaker panel on the wall and make additional drilling holes to fit it into the wall if it requires you to do so. The existing feeding wires will need to be connected to the bus bars and branch breakers of the main breaker panel. 

The main breaker will be situated in the middle of the main breaker panel. Finish the installation process by screwing in the circuit breakers.

Final Thoughts

The main lug panel and the main breaker panel differ from each other in many aspects. The main breaker panel works as a shut-off switch for the electrical system. But the main lug panel works as a distribution panel and it does not have a main breaker in it.