400 Amp Service(Meaning, Price, Installation, Troubleshooting)


Are your breakers tripping? Do your lights keep dimming? What about your outlets? Are they producing buzzing and crackling sounds? If the answer to all these questions is Yes, you should consider upgrading to a 400 amp service. But is that necessary? Will a 400-amp service solve all your problems? Can you even afford to perform such an upgrade?

What Does 400 Amp Service Mean?

The term ‘400 Amp Service’ refers to the capacity of your electrical service. The capacity of a home’s electrical service is measured in amps. Your electrical service’s amperage is the volume of current flowing through the wires. You normally find 100-amp electrical panels in old homes.

In the past, the number of heavy-duty appliances and electronic devices was quite limited. But that changed over the decades, so much so that many homes adopted 200-amp panels. 200-amp services are perfect for small and even medium-sized homes. They can accommodate basic heating and cooling systems along with conventional electric appliances.

You only need a 400-Amp service if you have a very large home that uses several powerful appliances and heating/cooling devices.

Why Do I Need 400-Amp Service?

400-Amp panels are only necessary for large homes that have significant electrical demands. It isn’t enough to add a few washing machines and space heaters. You can also run the average freezer and AC unit on a 200-Amp panel.

400-amp services are only suitable for homes with saunas, hot tubs, and other heavy-duty devices that use far more power than the average appliance.

You don’t have to upgrade your service unless you observe signs that show that your current electrical service is overloaded. That includes incessant breaker tripping, burning wires, and crackling switches, to mention but a few.

What Is Required For A 400-Amp Service?

Depending on your location, you may require a permit for the upgrade.  You need to use 400 AWG wire (355 copper amps, 270 aluminium amps) between the pole and the new electrical service, a larger current panel box, a 3-inch rigid conduit, and a circuit breaker box (if your home has a fuse box).

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How Can I Get 400-Amp Service?

In many cases, if you submit a request to your electrical service provider, they will upgrade your service. In some cases, you have to pay a fee upfront. In other cases, the upgrade is free. You have the option of hiring a third party, a contractor that has the knowledge, skill, and experience to upgrade your electrical service.

Once you contact this contractor, they will visit your home to evaluate your electrical service to identify the tools required to upgrade your electrical service. They will also determine the cost. Once you approve the estimate they have provided, the contractor will engage your electrical utility. They need the service provider to approve the location of the panel.

It is easier to hire a contractor because they tend to handle all the complicated details involved with upgrading your electrical service. That includes making certain that the upgrade adheres to the demands of the local codes.

How Do I Know If I Have 400-Amp Service?

service panel

The main circuit breaker will show the amperage of your electrical service. Thus, you need to look at the main breaker switch in their panel box. It will show a figure ranging from 50 to 400 amps. Naturally, a home with a 400-amp service will show 400 amps. 

How Much Does A 400-Amp Service Cost?

The 400-Amp service ranges from $2000-$4000. The greater the amperage, the higher the cost.

This is why a 100-Amp service costs a maximum of $2,500 whereas homeowners will spend as much as $3000 to install a 150-Amp service.

400 Amp Installation Cost

If you are lucky, your labor costs may range from $500 to $800. But in some cases, that figure can balloon to $3,000. That doesn’t include other costs. For instance, you may spend $600 to $2,500 to add a new electrical panel and wiring. Replacing a fuse box with a circuit breaker panel can cost as much as $2000.

Average cost for installing 400-amp

TimeElectrician Cost/HourAverage Cost
Max Time 20 hrs$120$2400
Min Time 8 hrs$40$320
Average Time 14 hrs$80$1120

The labor is one of the most costly components of a 400-Amp service installation. It can take the contractor anywhere between eight and twenty hours to complete the project. That is a modest estimate. Depending on the level of difficulty, it may take them days.

installation cost 400 amp

Home Advisor has also noted that some contractors prefer to install a pair of 200-Amp panels rather than a single 400-amp panel. They will expect you to pay the labour costs associated with the installation of each panel. The average electrician will charge anywhere between $40 and $120 per hour.

Cost To Upgrade To 400-Amp Service

The cost of upgrading to a 400-Amp Service ranges from $1,500 to $4,000.

Upgrade to400 amp
Panel Cost$500
Average hour14 hr
Electrician cost$80
Average upgrade cost$1620

How To Install 400-Amp Service?

This is a job you should leave to a professional. Some utility companies will do all the work. They will even provide the equipment you need for free. Others will ask you to pay for everything. You can also hire a contractor. They will determine whether or not you need current transformer metering for your electrical service.

They will also talk to the local authorities to acquire the necessary permits. This is on top of identifying all the requirements needed to safely and legally install a 400-amp service in your area. Once they consult your utility company to figure out the best location to mount all the equipment your home needs, they will proceed with their work.

You should talk to multiple contractors before you hire one to upgrade your electrical service. Compare their quotes until you find a contractor that fits your budget.

Who Should Install It?

You can use the power company or an electrical contractor you like.

What Size Wire Is Needed For 400-Amp Service?

You need an aluminum wire of 1000kcmil to install 400-amp service.

400 amp wire size

WireWire Size
Aluminium1000kmcil
Copper600kmcil

What Kind Of Wire Is Needed For 400-Amp Service?

400 AWG wire is required between the pole and the new service.

Is 400 Amps A Lot?

The load exerted by your home will determine the capacity of your electrical service. In other words, if you want to determine whether or not 400 amps is a lot for your home, you must start by determining your home’s total load.

You can do this by adding the wattage capacity of the general lighting branch circuits. Add the total to the wattage of all the outlets. Once this is done, you can add that figure to the wattage of all the large appliances in your home (washing machines, refrigerators, etc).

But the figure you will arrive at here won’t tell you anything. You have to take things a step further by subtracting 10,000, multiplying by .40, and then adding 10,000. Take the figure you have received at this point and then add it to the total wattage of all the permanent electrical items like furnaces and space heaters. You can finish by diving by 240.

iTrust has a breakdown that explains this process in greater detail. They also expect you to include a 20 percent buffer since you can only use 80 percent of the electrical panel’s total capacity.

BGH uses a slightly different equation to calculate a total load of your home. They take into account the square footage of the various rooms. Once you identify your home’s load, it will tell you whether you need a 100-amp, 200-amp, or 400-amp service.

Many homeowners will only upgrade to a 400-amp service when they realize that their electrical panel is overloaded. But even if you haven’t noticed the signs of overloading, while 400 amps is a lot, you should upgrade to a 400-amp service if you have the means because it allows you to prepare for any changes that may occur in the future. For instance, if you choose to add an outdoor kitchen that has numerous heavy-duty appliances.

400-Amp Service Disconnecting – Why?

When you hire a contractor to upgrade your home to 400-amp service, your power company will disconnect your home from the grid while the contractor works. Once they complete the upgrade, an inspector will check and approve everything they have done before the power company reconnects the power to your house.

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