April 7, 2023

Hardwired or plug-in?

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You've done your research and know which electric car you'll buy. Now you’re ready for the next step—choosing a charger.

There are many models of Level 2 electric vehicle (EV ) chargers available, which provide significantly higher charging speeds that the Level 1 chargers that come with most EVs. When deciding which charger suits you best, you'll want to consider the capacity of your electrical panel, your desired charging location, and whether to go with a hardwired or plug-in version.

 

Electrical panel capacity  

Any licensed electrician can help you check the capacity of your electrical panel to ensure it will be able to safely support the charger you want. If you need help finding an electrician near you, try our installer locator tool.  

 

Indoor vs. outdoor charging  

If you plan to keep your charger inside—in a garage, for example, where it's away from the elements—you can use a plug-in charger and plug it into a 240 V home electrical outlet. Plug-in chargers are often simpler to install, but if you'll be doing most of your home charging outside, we usually recommend installing a hardwired charging station.  

 

About plug-in EV chargers  

A plug-in EV charger connects to power by inserting its attached plug into a matching receptacle (electrical outlet). Enphase plug-in units do not come with conduits, like hardwired stations, but instead have high-quality 240 V supply cords that are 12 inches in length. This measurement includes the plug itself, and is the longest cord and plug length allowed under the National Electric Code.  

All Enphase chargers are safety certified by a Nationally Recognized Testing Laboratory and meet the requirements of UL 2594 and National Electric Code Article 625. If you come across a charger made by another brand with a supply plug length longer than 12 inches, there's a good chance it isn't safety certified.

Before you purchase a plug-in model, there are a few important things to know about plug and outlet safety.  

 

Plug and outlet safety
  • Always turn off the circuit breaker before plugging in and unplugging 240 V appliances, including EV chargers.

  • Residential 240 V plugs are designed for occasional relocation, such as moving an appliance or charger from one home to another, but most outlets are not rated for consistent plugging and unplugging.  

  • A dedicated NEMA receptacle is highly recommended. NEMA receptacles do wear out over time, especially with repeated insertion and removal of plugs occurs, so we recommend that a plug-in EV charger remain plugged in unless you need to move it.  

  • Check the receptacle to be sure it does not show signs of wear. A worn receptacle can cause the plug connection to overheat and become a fire hazard. Do not use a plug that gets excessively hot.  

  • Have an electrician verify that all wiring to the outlet is correct and in compliance with local code requirements before connecting your EV charger.  

  • Never use an EV charger with an extension cord or wall plug adapter. Plug the EV charger directly into the receptacle.  

  • Ensure the EV charger is mounted to the wall or placed on a support so it does not hang from the receptacle. Receptacles are not designed to support the weight of an EV charger.  

  • For more information on plug and outlet safety, please review the manual for the model you plan to purchase. Click here to view the Enphase HCS Manual. Click here to view all other EV charger manuals
     

Plug types for EV chargers  

If you decide to purchase a plug-in charger, you'll also need to decide which plug type to get. Some homes already have a 240 V outlet, so you can simply order the plug that matches your outlet. Enphase offers two types of 240 V plugs with our chargers to fit your needs; if you already have a suitable outlet, you can simply mount the station and plug it in to start charging your EV.  

If you have a 240 V outlet but need clarification on whether Enphase carries the matching plug type, please contact our product specialists. They can help you determine what kind of outlet you have and which electric car chargers would be safely compatible.  

If you don't already have a 240 V outlet, you can have an electrician install a new outlet that matches the plug you purchase. Once the outlet is installed, you can mount the station to the wall, plug it in, and start charging.

 

About hardwired EV chargers  

Hardwired chargers can typically be installed indoors or outdoors, though it's important to check with the manufacturer of the model you're interested in. All Enphase chargers, whether hardwired or plug-in, are rated for indoor and outdoor installation, but we generally recommend hardwired models if your charging location is in a driveway, carport, or other exposed location. 

The main advantage of hardwiring is that it provides a more weather-resistant connection to power. With a hardwired station, the supply power wires from the unit will be connected directly to the power wires coming from the electrical panel (circuit breaker). Hardwired units are typically more permanent; they can be moved, but to do so you need a certified electrician to uninstall the unit and then reinstall it at its new location.  

A hardwired station has three feet of flexible conduit that extends from the bottom of the charger, and service wires that come about six inches out of the conduit for easy installation into a junction box. 

 

Outdoor EV charger installations  

Hardwired chargers are recommended for most outdoor installations. When charging out in the open, the key benefits of hardwired over plug-in models include:

✔️ Flexibility and ease: Three-foot flexible conduits provide more installation flexibility than 240 V 12-inch supply plugs.  

✖️ When installing a plug-in charger outdoors, you will typically be required by electrical code to have a “While-in-Use” weatherproof cover installed over the 240 V outlet. These covers allow the 240 V supply plug to enter from the bottom, requiring the 12-inch supply plug to make a 180-degree bend if the supply plug comes from the bottom of the unit .  

✔️ Built-in power and speed: EV chargers are high-power, continuous-use devices, and hardwiring provides the best power connection. Hardwiring is consistent with other outdoor high-power continuous-use devices, such as HVAC equipment and sprinklers. With a hardwired charger, you generally don’t need to have a GFCI (Ground Fault Circuit Interrupter) circuit breaker in place.  

✖️ For a 240 V plug-in EV charger, you must have a GFCI circuit breaker, per National Electric Code requirements.  

✔️ Worry-free consistency: Another advantage to a hardwired EV charger is avoiding GFCI-caused nuisance-tripping. Enphase chargers provide 20 mA GFCI protection and feature circuit reclosure that restarts charging automatically in the case of an interruption, so you can just set it and go about your day.  

️✖️ Using an outlet with a GFCI breaker to supply a charger can cause the breaker to experience nuisance-tripping while charging. The trip threshold for a standard U.S. GFCI breaker is 5 mA, which is low for EV charging. At the 5 mA trip threshold, you may experience nuisance-tripping of the circuit breaker during charging due to noise on the line generated by the vehicle.  

 
We're here to help  

If you'd like more help making a decision about hardwired or plug-in chargers, or have any other questions about your charging needs, please contact us. We'll be happy to get you the answers you need to choose the best EV charger for your home.