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Electric vehicles are becoming more common every year, and with that comes a major increase in homeowners installing EV chargers in their garages. Most people quickly realize that charging at home is by far the most convenient option. You come home, plug the vehicle in, and it is ready to go the next morning.
What many homeowners do not realize, though, is that an EV charger is one of the most demanding electrical systems in the entire house. When installed incorrectly, undersized, or added onto an already stressed electrical system, it can create serious safety and reliability issues. (For a broader overview before getting started, see our earlier post on installing an EV charger at home and what you need to know first.)
What Is a Level 2 EV Charger?
In residential applications, the most common EV charger is a Level 2 charger.
A Level 2 charger typically operates on a 240 volt circuit, similar to an electric dryer or range, but usually at much higher sustained loads. Depending on the charger and vehicle, most Level 2 chargers draw anywhere from 32 amps to 80 amps continuously while charging.[1]
Compared to a standard Level 1 charger plugged into a regular 120 volt outlet, a Level 2 charger charges significantly faster. In many cases, homeowners can fully charge their vehicle overnight instead of waiting an entire day or longer. For most EV owners, Level 2 charging is the practical long term solution.
If you are still deciding on a setup, our guides on which EV charger is right for your home and hardwired versus plug-in chargers walk through the trade-offs in more detail.
Why EV Chargers Are Different Than Most Electrical Loads
Most people think of electrical loads in short bursts. Your microwave runs for a few minutes. Your hair dryer runs for maybe 10 or 15 minutes. Even your oven cycles on and off.
An EV charger is different. Once charging begins, the charger can pull heavy electrical load continuously for several hours straight without stopping. That is what makes EV charging systems unique, and why proper installation matters so much.
In fact, outside of electric heat systems, there are very few residential electrical loads that stress a home’s electrical system the way an EV charger does.
What the code says
Under the National Electrical Code (NEC), a continuous load is defined as a load where the maximum current is expected to continue for three hours or more.[2] EV charging equipment is specifically addressed in NEC Article 625, and is treated as a continuous load.[3] The NEC also requires conductors and overcurrent protection serving continuous loads to be sized at 125 percent of the continuous load.[4]
A poorly installed EV charger can lead to:
- Overheated wiring
- Damaged breakers
- Melted connections
- Nuisance tripping
- Panel overload issues
- Increased fire risk
Improperly installed high-load circuits like this are among the top electrical hazards every homeowner should know about. This is not an area where shortcuts should ever be taken.
Proper Installation Matters
A professional EV charger installation involves much more than simply adding a breaker and plugging in a charger. Before installation, several things should be evaluated:
- Existing panel capacity
- Available amperage in the home
- Condition and age of the electrical panel
- Proper wire sizing
- Breaker compatibility
- Charger location
- Ventilation and environmental conditions
- Future charging needs
In some homes, the existing electrical service can handle the charger with no issues. In others, a load calculation may reveal that the electrical service or panel needs upgrading before safely adding the charger. This is especially common in older homes that already have electric ranges, hot tubs, electric water heaters, or electric HVAC systems. If you are not sure about the condition of your panel, our post on whether your electrical panel is safe walks through what to look for.
One common mistake homeowners ask about is whether they can simply install a bigger breaker to handle the new load. The answer is no. A bigger breaker does not fix an undersized wire or an overloaded panel. It just removes the protection that is supposed to keep the wiring from overheating. (We covered this in more detail in Why Installing a Bigger Breaker Is Not the Solution.)
Why Permits and Inspections Are Important
One of the biggest mistakes homeowners make is installing EV chargers without permits or inspections. A permit and inspection are not paperwork for the sake of paperwork. They help ensure:
- The installation meets current electrical code
- Proper wire and breaker sizing were used
- Connections are torqued correctly
- The panel is not overloaded
- Grounding and bonding are correct
- The installation is safe for long term continuous use
Inspections also help confirm that quality materials and components were used in the installation. For a closer look at the brands and components we install, see how reliable the fixtures, devices, panels, and breakers we install are.
Permits and inspections also protect homeowners financially. If there is ever an electrical fire or insurance claim tied to an unpermitted electrical installation, insurance companies may look very closely at the work that was performed. Having a properly permitted and inspected installation helps protect the homeowner and verifies the work was completed correctly.
Permit requirements vary by jurisdiction. In South Dakota, electrical work is regulated by the South Dakota Electrical Commission.[5] A licensed electrical contractor will pull the appropriate permits for your area as part of the job.
Choosing the Right EV Charger Installer in Rapid City
As EV adoption continues to grow in Rapid City, more homeowners are looking into installing chargers in garages, shops, and new homes. This is not a project where the cheapest option is always the best option. For a full picture of what we offer, visit our Rapid City service page to see how we approach every install.
A properly installed EV charging system should:
- Be sized correctly for the home
- Meet NEC requirements
- Be installed with quality materials
- Have clean, tight electrical connections
- Include permits and inspections
- Be designed for years of safe continuous operation
When installed correctly, home EV charging is extremely convenient, reliable, and safe. We work with homeowners across the Black Hills, from Rapid City to Spearfish, Sturgis, Belle Fourche, Piedmont, and Hot Springs.
Final Thoughts
Most people think of an EV charger as another outlet. In reality, it is one of the heaviest continuous electrical loads most homes will ever see. That is why professional installation matters.
A properly designed and permitted EV charging system helps protect your home, your vehicle, and your electrical system while giving you the convenience of reliable charging every day.
If you are planning an EV charger installation in Rapid City or anywhere across the Black Hills, Wires R Us is happy to walk you through your panel, your charger options, and what a proper installation looks like for your home. Visit our Rapid City electrician page for local service details, browse the electrical FAQs for more answers, or get in touch to discuss your project.
References
- U.S. Department of Energy, Alternative Fuels Data Center. Developing Infrastructure to Charge Plug-In Electric Vehicles. Available at afdc.energy.gov/fuels/electricity-infrastructure-development
- National Fire Protection Association (NFPA). NFPA 70: National Electrical Code, Article 100, definition of “Continuous Load.” Available at nfpa.org/codes-and-standards/nfpa-70-standard-development/70
- National Fire Protection Association (NFPA). NFPA 70: National Electrical Code, Article 625, Electric Vehicle Power Transfer System.
- National Fire Protection Association (NFPA). NFPA 70: National Electrical Code, Article 210.19 and 210.20, branch circuit conductors and overcurrent protection for continuous loads (125 percent sizing requirement).
- South Dakota Electrical Commission, Department of Labor and Regulation. Electrical Permits and Licensing. Available at dlr.sd.gov/bdcomm/electrical/
This article is for general educational purposes. Electrical codes are updated periodically, and local jurisdictions may adopt different editions of the NEC or apply additional amendments. For specifics on your home, consult a licensed electrical contractor.
