This article was updated on: December 7th, 2021
The size of your electrical panel is the indicator of how many electrical units or appliances you can run in your home at one time. While some homes run on a combination of electricity and gas, allowing them to function with a smaller panel, other homes are fully electric and require much larger panels.
Your electrical panel, or breaker box, splits the power coming into your home to a number of circuit breakers. Each of these circuit breakers controls the flow of power to a particular room or appliance in your home. A breaker box that's too small doesn't provide enough capacity for power to flow through your home, so you'll likely end up trying to connect too many things to each circuit. Not only is this inconvenient as it can occasionally cause the circuit breakers to trip, or shut off, having too small or too old a breaker box is indicative of bigger problems such as substandard wiring in your home.
The danger of not replacing an old, faulty breaker box or substandard wiring is that they can catch fire from their failure to prevent overloads in your home’s electrical system.
It is important to know the signs that your breaker box is too small or faulty as well as the steps you can take towards replacement.
Your electrical panel is responsible for delivering electricity to numerous parts of your home in order for you to live safely and comfortably. Living with an overloaded or malfunctioning electrical panel can be dangerous and cause quite a headache. Pay attention to these possible signs:
When a circuit breaker regularly trips or a fuse repeatedly blows, it is a sign that you are making excessive demands on the circuit and need to move some appliances and devices to other circuits. If there are no other available circuits, it may be time for an upgrade.
Electrical circuits are limited in the amount of power they can each draw, and once the demand on a circuit has been exceeded it becomes overloaded. If your lights dim when your air conditioner, clothes dryer, or microwave turns on, it may be time to upgrade your electrical panel.
When there’s too much demand on one outlet, it starts to feel warm because of the increase of electricity. Loose electrical terminations and frayed wires can also cause your outlet to feel warm because the electricity escapes and heats the outlet cover. Most homes are designed to have at least one outlet in a room be on a different circuit to prevent excessive demand.
A breaker box with rusted parts has most likely had water get into it at some point. Water and electricity can be a fatal combination, so have the breaker box inspected and replaced if necessary.
Scorch marks on your electrical panel are a sure sign of trouble. These occur when faulty wiring allows electricity to arc or jump small gaps in the wiring or wiring connections. The wiring in your box should be thoroughly checked and the electric panel and wiring replaced if necessary.
Ungrounded outlets in your home are often a sign of substandard or outdated wiring. Have an electrician inspect your system to see if a new electrical panel or other upgrades are required.
Adding a sub-panel to your home's electrical system is an accepted way to add capacity to the electrical system, but if you have more than one sub-panel in your home, it may be smarter and safer to consolidate all of these electrical systems into one larger panel.
Unfortunately, there are several types of electric panels that are well-documented as being unsafe. In particular, Federal Pacific Electric panels and Zinsco electrical panels have a history of defective design and workmanship that has led to numerous house fires. If you believe you have one of these circuit breaker boxes, consult with a licensed electrician right away.
Of course, it’s common to use extension cords in any home but too many can actually cause a major safety hazard. Extension cords were not created for permanent use within the home and can get in the way and even lead to damaged outlets.
If you find that you have extension cords plugged into many of your home’s outlets, it’s probably time to upgrade your electrical panel to a larger size in addition to installing more outlets.
Most older homes were constructed with a generic 60-amp electrical panel that could provide all of the home’s electricity, but as times have changed, so have homes and their electrical needs. Today, a 60-amp electrical panel will struggle or fail to get the job done and you will have to upgrade to one of the options previously listed. Calculate your home's wattage needs to determine exactly what size your home requires.
Determining the proper size of an electrical panel for your home is also dependent on how many and what type of appliances you have. Some appliances like computers, sound systems, and televisions require much less electricity than other larger appliances like washers and dryers, air conditioning units, and heating systems.
Believe it or not, you don’t have to be an electrician to figure out the proper size for your home's electrical panel. Choosing the right size can be calculated with some simple calculations.
Take the square footage of your home and multiply it by 3. Let’s say your home is 1,750 square feet. Multiply 1,750 by 3 to get 5,250. This number is your home's baseline wattage needs.
Next, you’ll need to determine the exact wattage needs for your kitchen. You will need a small appliance, a 20-amp single-pole circuit for your kitchen and to find the amount of wattage needed, you can multiply 20 amps by the 120 volts it will be operating on, equaling 2,400 watts. Now add the 2,400 watts to the 5,250 watts you’ll need for your home.
5,250 watts + 2,400 watts = 7,650 watts
For your kitchen circuits, you’ll need to calculate in the electric range (at a 50-amp double-pole dedicated breaker, 50 amps times 220 volts) and the dishwasher, if applicable (at 20 amps times 120 volts). This will give you 11,000 watts and 2,400 watts to add to your total. 7,650 watts + 11,000 watts + 2,400 watts = 21,050 watts
Your washer and dryer are important appliances to account for when determining the correct electrical panel size. Your washer requires a 20-amp single-pole dedicated breaker (20 amps times 120 volts) and your dryer requires a 30-amp double-pole dedicated breaker (30 amps times 220 volts). Now add 2,400 and 6,600 to your total.
21,050 watts + 2,400 watts + 6,600 watts = 30,050 watts
As per the National Electrical Code, you must calculate your home's wattage needs before adding in your central air conditioning unit and heating unit. The first 10,000 watts of your home's total needs are calculated at 100 percent and the remaining balance, which in this case is 20,050, is to be calculated at 40 percent. This coincides with the NEC.
20,050 x .40 = 8,020 watts
8,020 watts + 10,000 watts = 18,020 watts
Now you can calculate the wattage needs of your air conditioning and heating unit. These units will run on a 60-amp double-pole dedicated breaker which can be calculated by multiplying 60 amps by 220 volts for a total wattage usage of 13,200 watts. Add this to your new total.
18,020 watts + 13,200 watts = 31,220 watts
In compliance with the NEC, divide your total wattage of 31,220 watts by 230 to calculate your total amperage. In this example, the total amperage for your home’s needs would be 135.73913. Electrical panels for a private residence are available in sizes of 100 amps, 125 amps, 150 amps, and 200 amps. Since we landed on an amperage of 135.7 amps, we must round up to the next highest panel of 150 amps to suffice your home's wattage needs.
As we've seen, there are many reasons why you may want to consider an electrical panel replacement. Let's dive into some of the details on what's involved in getting a new electrical panel.
The lifespan of an average electric panel will range from 25 to 40 years. However, these estimates don't take into account environmental conditions. For example, if your electrical panel is in a damp location, rust may set in and corrode vital components, shortening its lifespan.
The main reason to replace electrical panels is that they're not up to the job at hand. If you are using significantly more electricity than your home's electrical system was designed to handle, you'll need to make the investment in a new electrical panel.
The primary question you'll probably have about electrical panel replacement is the cost. This is dependent on the type of electrical panel you have in your home.
Replacing a fuse box may involve more than just wiring in the new circuit breaker box. Fuse boxes were used when our homes had more modest electrical requirements, so upgrading some of the existing wiring may be needed as well. Circuit breakers are much more convenient to use than fuses and your fuse box is probably limiting the amount of electricity you can safely use in your home.
The average cost to replace a fuse box with a new electrical panel that uses circuit breakers will be in the $1000 to $4000 range.
Modern homes typically will have electrical panels larger than 100 amps, but some older homes may have one. An electrical panel upgrade is a good idea if you have a 100-amp breaker box. The extra circuit breakers will make it easier to add additional appliances or outfit a home office.
The typical cost to upgrade a 100-amp electrical panel will be somewhere between $900 to $1500.
A 200-amp home electric panel is pretty much the norm for modern homes. However, if you're adding an addition, a workshop, or an outbuilding, you may require more capacity and circuit breakers than a 200-amp electric panel can provide.
Depending on the size of panel you'll move to, the average cost of an electrical panel upgrade in this case will be about $1500 to $2000.
As we've seen, there are many reasons for replacing your electrical panel. You may need more capacity and additional circuit breakers to handle an increased electrical load in your home. Some quick calculations can tell you if that's the case.
Your electrical panel may be giving you other signs that it needs to be replaced. Look out for a few common and obvious signs: flickering lights; appliances that aren’t performing to their full potential; your breakers tripping from using multiple appliances at once; or an outlet, switch, or breaker box that is malfunctioning or feels warm to the touch. If you are experiencing one or more of these problems, it's time to invest in a new circuit breaker box.
Having an old or undersized electrical panel in your home can not only be an inconvenience, but can also become incredibly dangerous. It’s important to know the signs to look out for when your panel has become insufficient for your home’s wattage needs. If you need help determining the proper size electrical panel for your home or have any further questions, do not hesitate to contact one of our experienced electricians.