Electrical Service Panel Basics For Homeowners (2023)

Home Improvement



Lee Wallender

Electrical Service Panel Basics For Homeowners (1)

(Video) Main electrical panel explained - Load center - service panel

Lee Wallender

Lee has over two decades of hands-on experience remodeling, fixing, and improving homes, and has been providing home improvement advice for over 13 years.

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Updated on 05/17/22

Reviewed by

Larry Campbell

Electrical Service Panel Basics For Homeowners (2)

Reviewed byLarry Campbell

Larry Campbell is an electrical contractor with 36 years of experience in residential and light commercial electrical wiring. He worked as an electronic technician and later an engineer for the IBM Corp. is a member of The Spruce Home Improvement Review Board.

(Video) How To Wire A Main Electrical Panel - Start To Finish! NEATLY And VERY DETAILED

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You may know it as a metal panel located in a distant part of your home that you rarely think about it. Then perhaps the power goes out in the kitchen because you turned on the blender. Hitting the reset button on the countertop GFCI outlet doesn't fix the problem. Suddenly you need it: the electrical service panel box.

Homeowners might visit their electrical service panel box no more than once a year. For older homes with aging electrical systems, it might become a routine visit. For newer homes, there may never be a need to visit it.

Understanding the basics of your home's electrical service panel will keep you safe and your home well-lit and energized. You'll even save money since operating an electrical service panel is crucial to every electrical repair, from replacing an outlet to wiring an entire room for remodeling.

What an Electrical Service Panel Is

The electric service panel is the connection between the external wires coming from the street and the internal wires of your home's electric system.

(Video) Circuit Breaker and Electrical Panel Basics

The service panel is the central distribution point that connects the service wire or service drop—the main wire coming from the outside into the house—to the exit wires that split off and service different parts of the house. These exit wires are called branch circuits or branch wire circuits.

In single-family residences, the owner of the building owns the electric service panel, not the electric company. Thus, the owner is responsible for all issues related to the electric service panel.

Circuit Breaker Service Panels and Fuse Boxes

Electric service panels have a number of different names: fuse box, fuse panel, and circuit breaker panel. Today, most homes have what is officially called the electrical service panel, or simply, the service panel.

A circuit breaker panel is not exactly the same as the fuse box because it has mechanical, toggle-switch circuit breakers, not fuses, but it does perform the same function. The older fuses screw or pull in or out, as opposed to the rocker-style method of installing and removing circuit breakers.

Power comes into the house from a service drop, connects to the service lugs within the service panel, and is split into separate circuits throughout the house. All of your home's power is located in the service panel.

The electrical service panel provides 100, 200, or more amps of power to a home. Homes built between 1950 and 1965 may have these 60-ampere fuse boxes, often with just four fuses.

Where to Find the Electric Service Panel

By its nature, the main service panel is usually kept away from the main household activities. Likely locations:


The garage often hosts the electric service panel because it is covered, accessible, and close to other services. Look on the wall adjacent to the house.


If the home has a basement, chances are good that the electric service panel will be located there. Look on an exterior wall.


If the electric service panel is located in a hallway, it will usually be one that leads to the garage or outdoors rather than near the main entrance.

Pantry or Closet

The electric service panel may be tucked away in a built-in pantry adjacent to the kitchen or in a utility closet.


Look outside for the service panel, usually in a covered location. While not typical, a service panel may be found on the outside part of an exterior wall, especially in the case of older fuse boxes.


One way to find your electrical service panel is to first go outside and locate the service drop and service head on your roof. The service panel should be directly below, at one of the home's lower levels. For buried power lines, the line will start at the street and connect to the home near the front or side of the home.

(Video) Electrical Wiring Basics

Electrical Service Panel Components

  • Panel door: An outer panel door that swings open
  • Removable cover: Protective cover with spaces for the circuit breaker switches
  • Main breaker: Large switch that shuts off incoming power to all of the circuits
  • Lugs: Metal lugs attached to thick wires that lead out and connect to the service drop
  • Circuit breakers: Removable 15A or 20A switches that control individual electric circuits
  • Spaces: Open or spare spaces on the service panel for creating extra circuits (sometimes, all open spaces will be filled with circuit breakers)
  • Wires: Assortment of wires that run from the circuit breakers to the circuits that service areas of the house


Do not touch the lugs. Even with the main breaker shut off, the lugs are still energized.

Electrical Service Panel Safety Considerations

When the service panel's outer door is closed, the service panel is safe to touch under normal conditions. When the outer door is open and the circuit breaker switches are exposed, the panel is still safe to touch under normal conditions.

It is dangerous to work on an open electrical service panel with both the door and the protective front cover removed. Unlike the shock from a receptacle, which may or may not be fatal, a shock from the service lugs will most certainly be fatal or seriously hurt you.

In the service panel, two black heavy-gauge wires enter the panel from the meter base or a remote disconnect. The main entrance cable can enter the panel from the top, bottom, or even the sides. These are the ends of the service wires that come into your house from the outside. Avoid touching these wires or anything that these wires touch.

With that protective cover removed, shutting off the panel's main circuit breaker switch will not necessarily keep you safe. The main breaker cuts off the power to all of the home's branch circuits, but it does not shut off the power coming into the panel on the utility service lines or to the lugs the lines are connected to.

While it is often easy enough to be cautious of areas in the service panel that your hands touch, also be especially careful of tools that you are holding. The exposed service panel, screwdrivers, wire cutters, wire strippers, pliers, and more are items that can potentially touch parts of the service wires and transmit an electric shock to you.

Installing Additional Circuit Breakers

You can add more circuits and circuit breakers inside your electrical service panel box as long as there are spaces. In many cases, the service panel will have available spaces.

Some older homes may have completely filled out their spaces. In this case, an electrician can install a new, larger service panel box or add a smaller sub-panel and feed it from the main panel. This will require you to move older circuits to the sub-panel to make space for the feeder breaker.


An easy solution to a service panel that's full of circuit breakers and has no available slots: tandem circuit breakers. Tandem circuit breakers fit in the same-size slot as a normal breaker but can serve two separate circuits.

Generally, you can determine if there are more spaces by looking at the metal knock-outs on the panel itself. Any space that is not knocked out should be available for the insertion of another circuit breaker, but this is not always the case. Remove the cover to see how many open spaces are available.

Do-It-Yourself Electrical Panel Repairs and Remodels

Homeowners are allowed to work on the service panel, but many choose to avoid this for safety reasons. Most homeowners only have the experience of opening the outer door of the electrical service panel to flip on a disabled circuit breaker.

Since you own the service panel, you are allowed to work on its interior section for any type of work. The most common activity to remove and replace a circuit breaker.

(Video) A look inside a British home electrical panel.

Many seasoned do-it-yourself homeowners still choose to call in an electrician when it comes to any work that involves removing the protective front cover.


What is the difference between a breaker box and an electrical panel? ›

Electrical panels are metal boxes, that have a panel cover, and store circuit breakers. Circuit breakers are mechanical switches that automatically detect current overage. Circuit breakers do not have to be replaced when they are triggered by a current overage. Rather, the switch can just be reset.

How many breakers are allowed in a 200 amp panel? ›

Most 200-amp breaker panels have 40 to 42 slots of single-pole breakers or 20 slots for double pole breakers.

How many amps service panel do I need? ›

Most homes require an electrical service of at least 100 amps. This is also the minimum panel amperage required by the National Electrical Code (NEC). A 100-amp service panel will typically provide enough power for a medium-sized home that includes several 240-volt appliances and central air-conditioning.

How do I choose an electrical panel? ›

Electrical panels differ by the number of circuits they accommodate and the amount of amperage they provide. Find your current panel's amperage listed on its main breaker. When replacing your electrical panel, either match the amperage capacity of your current model, or upgrade if your power needs have grown.

How do I know what size electrical panel I need? ›

How Many Amps is Your Panel Box? - YouTube

Do panels need a main breaker? ›

You need a main breaker in a panel when the overcurrent protective device (breaker or fuse) on the feeder supplying the panel has an ampere rating higher than that of the busbars of the fed panel, such as a service panel or when tapping onto a larger ampere rated feeder. This protects the busbars.

Why do my breakers add up to more than Main? ›

There are a couple of reasons why this is allowed. First, every appliance and other load in a home is not turned on at the same time. And second, breakers for some appliances are rated at much more than the appliance uses when operating.

What is the 42 circuit Rule? ›

Definition of the 42 Circuit Rule

having more than 10 percent of its overcurrent devices protecting lighting and appliance branch circuits. Such circuits have a connection to the neutral of the panelboard and overcurrent protection of 30 A or less in one or more conductors.”

How far can subpanel be from main panel? ›

The cable run from the main panel to the sub panel will be about 150 feet. My question is there a code requirement on how far the sub panel feeder cable can be ran. There is no maximum distance and no NEC requirement to provide voltage drop compensation.

Is 200 amp service enough for all electric house? ›

200-amp service is the current standard for new homes and updated service panels. It can supply all standard electrical needs in a typical family home but may not support a large electric heating system. In large homes, 250-amp or larger service capacity may be needed, particularly if the home has electric heating.

Is 100 amp service enough for a house and garage? ›

In general, homes under 3,000 square feet can use a 100 AMP panel as long as they don't use air conditioning or electric heat. Homes over 3,000 square feet and homes that rely on electric heat and air conditioning will typically be better served by a 200 AMP panel.

How much will a 200 amp service panel cost? ›

On average, the cost to upgrade an old electrical panel of 100 amps to a new one of 200 amps is anywhere from $1,300–$3,000. Upgrading from 60 to 100 amps costs $800–$1,500, replacing a 200-amp panel with a 300-amp panel costs $1,800–$3,500, and upgrading to 400 amps costs $2,000–$4,000.

What brand electric panel is best? ›

Siemens is one of the top electrical panel brands and many professional electricians will recommend it. The quality of the materials used, the durability and strength of the panels, but also their flexibility make them a top choice for many households.

How many receptacles can be on a 20 amp circuit? ›

How many outlets can be put on a 20 amp circuit safely? A rule of thumb is to factor a maximum draw of 1.5 amps to each receptacle, which means you can put 10 outlets on a 20-amp circuit.

How many amps can a house panel handle? ›

The main breaker box for your home will only handle the current it is rated for and is limited to the size of the breaker and the amount of current coming in from the main supply. Modern main breaker boxes are generally rated to handle 100, 150, or 200-amps.

How many amps does a average house use? ›

Average size homes with gas or oil heating systems and hot water systems generally do not need electric service of greater than 100 amperes capacity. Of course, this can also depend on the electrical usage of the occupants, and the use of other electrical appliances. 125 Amperes.

How do you tell if your house is 100 amp or 200-amp? ›

How To Tell What Amp Service Is In Your House - YouTube

Can I put a 200-amp breaker in a 100 amp panel? ›

Can I Replace My 100 Amp Panel With a 200 Amp Panel? - YouTube

What is the 6 breaker rule? ›

The “six breaker throw rule” was a requirement in the National Electrical Code that a service must have have a main disconnect that shuts off all power and it cannot take more than six switch throws to do it, and the main disconnect(s) also must be clearly marked, as in the photo above.

What is the 6 hand rule? ›

Remember, the Code allows up to six throws of the hand to terminate power at an electrical service. This may include flipping a single-pole, two-pole, or even three-pole circuit breaker to complete the job.

Does a subpanel need a ground rod? ›

Yes, any sub panel outside of the main building requires it's own ground rod and a ground wire back to the main building. And yes, a sub panel in the same building as the main does not need a ground rod - only the ground wire.

Is a breaker the same as a panel? ›

To summarize, both circuit breaker and power panels are needed to protect the electrical systems in an aircraft. Circuit breakers are used to protect the system from overload while the Power Panel turns off an entire section of the avionics with one switch.

What is the electrical panel in a house called? ›

What is an Electrical Service Panel? What you should Know, How we ...

Do all electrical panels have a main breaker? ›

In newer homes, every electrical panel has a main breaker. Mobile homes, condos, townhouses, and other housing situations can have the panel's main breaker outdoors by the electric meter or in another location. It is the main breaker if you find a switch that shuts down power to your home.

What is the electrical panel called? ›

An electrical panel box goes by several names, including breaker box, load center, breaker panel, and service panel. Regardless, the typical electrical panel for a home is a steel box that's mounted on a wall in the garage, basement or laundry room.

How long do electrical panels last? ›

The average lifespan for an electrical panel can range from 25-40 years. There is a wide range of variability due to several things, such as: Power surges. Wear and tear.

How do I know if my electrical panel is full? ›

How Do I Know If My Panel Is Maxed Out? - YouTube

Are Square D electrical panels Safe? ›

The Square D QO Plug-on-Neutral Load Centers, also known as, load centers, breaker boxes or electrical panels, can overheat and cause thermal burns or fires, according to an announcement with the U.S. Consumer Product Safety Commission.

Can ground and neutral be on same bar? ›

The answer is never. Grounds and neutrals should only be connected at the last point of disconnect. This would be at main panels only.

How many breakers are in a 100 amp panel? ›

Typical 100-amp panels have 20 circuits, meaning they can handle 20 full-sized breakers. 20/24 panels can hold 16 full-sized and 4 twin breakers (24 circuits in total). The number of breakers can max out to 30-42, too, depending on the design of your 100-amp pane.

How much does a new electrical panel cost? ›

The average cost of an electrical panel upgrade is between $1,300 and $3,000. This is the typical range for upgrading from 100 amps to 200 amps; for smaller or larger upgrades, you may pay anywhere from $800–$4,000. Below are the factors that determine the total cost: Panel size: Panel size ranges from 60–400 amps.

Can you change electrical panel without turning off power? ›

Yes.. a breaker can be changed without turning off the panel but there are laws in most countries saying do not do it. You can change an outlet or switch without turning off the power but you probably are going to get a shock.

Can you get electrocuted if the main breaker is off? ›

The short answer is Yes! There are many factors that come into play that can cause you to still get shocked when performing electrical work even though you have shut off the breaker to the area that you are working on. The most common issue is when the breaker is incorrectly labeled.

What can throw a main breaker? ›

There are a number of reasons why the main breaker might trip. Lightning strikes, power surges from the utility company, or an overload to the electrical panel can all cause the main breaker to trip.

How many receptacles can be on a 20 amp circuit? ›

How many outlets can be put on a 20 amp circuit safely? A rule of thumb is to factor a maximum draw of 1.5 amps to each receptacle, which means you can put 10 outlets on a 20-amp circuit.

Is a 200 amp panel enough? ›

200-amp service is the current standard for new homes and updated service panels. It can supply all standard electrical needs in a typical family home but may not support a large electric heating system. In large homes, 250-amp or larger service capacity may be needed, particularly if the home has electric heating.

How many breaker boxes can you have in a house? ›

Typically, every home has one main electrical panel that controls the amount of electricity entering the home. Sometimes, there's also a “sub-panel” that controls various circuits in a different area.


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2. How To Wire a House Main Electrical Panel Load Center & Layout Tips Full Step By Step Process 200Amp
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3. Understanding Your Home's Electrical System: The Main Panel
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4. Anatomy of an Electrical Panel
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