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Electric vehicle charging station installation at residential property by Wells Electrical Inc. in San Francisco

Answers to 5 Key Questions Before Installing a Home EV Charger

Electric Vehicles (EV) and Plugin Hybrid Electric Vehicles (PHEV) charge by inserting the connector on the end of the charging cable into the charging “socket” in your vehicle. EVs in North America use one of two connector designs: the North American Charging Standard (NACS) or the SAE J1772. The NACS design, developed by Tesla Automotive, was exclusive to Tesla EVs but is now being adopted by other EV manufacturers switching over from the SAE J1772 design.

As an EV owner, you need to determine which connector design your EV uses and install an EV charger that has the matching connector. There are adapters you can purchase separately that will convert the connector end of the charging cable between either connector type. Using such adapters allows EV owners to use a charger with either a NACS or SAE J1772 connector to charge their vehicle. So, for instance, if you install a charger with a SAE J1772 connector and later get an EV with a NACS charging “socket,” you can affix an adapter to your charger to charge your EV.

At the time of this writing, only the latest Tesla EV charger, the “Tesla Universal Wall Connector,” comes with an integrated adapter that saves you the effort of affixing the adapter. While lifting the charging cable from the charger housing, with the push of a button, you can select whether the adapter is attached. A little convenience that can also save you from losing the adapter, as it’s either stored in the charger housing or locked to the cable connector.
Other EV charger manufacturers are increasingly offering a choice of connector design. You order the model that fits your EV and could simply buy an adapter separately if you ever needed the other connector design.

How to Decide on the Best Location for an EV Charger?

1. Consider the Distance Between the EV Charger and Your Vehicle

When deciding on the location of your EV charger, look for shorter distances. Try to keep the distance between the EV charger and the vehicle less than 24 ft, as that is the typical length of a level 2 charger cable. The cable is somewhat bulky (think garden hose), so it will run along the ground then up to the EV charger and your EV’s charging socket, leaving you less length than you might think.

2. Consider the Distance Between the Charger and the Electrical Panel

Try to keep the distance between the charger and the electrical panel short, as well. An electrician will need to install wiring between these, so increased distances increase cost. You may not have enough available power without connecting from your main electrical panel, which could be further away from your desired charging location. Your main electrical panel is the one with the electrical meter attached, typically on the exterior of your home.

How Much Power Do I Have for an EV Charger?

Every EV owner uses a different amount of electricity in their home. Some have electric cooktops, ovens, clothes dryers, water heaters, and air conditioning. Some have only one or two of these appliances, with the others fueled by natural gas or propane. So, how much power you have for an EV charger, or whether you even have enough, depends on how much power you have coming into your home from your utility company and how much you are using already with electric appliances and lighting.

A licensed electrician can fill out a load calculation form to determine how much power you are likely to be using and how much is available for powering an EV charger. Such load calculations are required in many cities/counties when applying for a permit for EV charger installation.

What Will It Cost to Install the EV Charger?

The cost of installing a level 2 EV charger in your home depends on the following:

1. Amount of Wiring Needed

The amount of wiring to be installed between the electrical panel and EV charger. The greater the distance between the electrical panel and the EV charger, the more time and materials will be required.

2. Wiring Path Between the Electrical Panel and EV Charger

Installation is faster, and thus less costly, if electrical conduit with wire inside can be installed on the surface of walls and ceilings. If, however, wiring needs to be run through an attic or crawlspace or inside walls, this may take more time, and possibly a second electrician to help, increasing installation costs.

3. Available Space and Power in the Electrical Panel

Level 2 EV chargers require a new circuit and circuit breaker in your electrical panel. If you don’t have available space in your panel, there are options to use different style breakers or add a small subpanel. Each option has associated costs for the additional time and materials required. Options available to you can be determined by a licensed electrician.

4. Cost of the Electrical Permit in Your Area

A level 2 EV charger draws a lot of electricity through your electrical system and keeps drawing it for 6-12 hours depending on your EV and charging rate. This is a much greater draw than an electric clothes dryer, cooktop, or oven when you consider how long the charger is functioning.

 

Electrical permits for installing an EV charger are important in ensuring that your installation is safe and meets local and national electrical codes. Poor connections or undersized wiring can quickly cause heat build-up and lead to fires. Permits for electrical work vary greatly between cities/counties. Many have permit rates posted on their websites under “level 2 EV charger” or “additional circuits,” and a licensed electrician can provide you with the cost. Keep in mind that many permits require a final inspection by the city/county with the electrician present, so expect the electrician to charge some amount for that time as well.

A licensed electrician familiar with EV chargers can help you with these decisions, but we think our installs are most successful and affordable when customers have considered these five questions to help understand the choices involved and how they may affect safety and cost.

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