Adding an EV charger, generator or other big appliance: what to know first

Electric vehicles, heat pumps, induction ranges, hot tubs and backup generators all put new demands on a home’s electrical system. A little planning before you buy makes the installation smoother and safer.

Start with a load calculation

A licensed electrician can calculate how much power your home already uses and whether your panel and service can handle the addition. Many homes can, sometimes with a load-management device that shares capacity between appliances. Others need a panel or service upgrade, which can add time and cost, so it helps to know early.

EV chargers

• A standard 120-volt outlet (Level 1) adds roughly 5 miles of range per hour of charging, according to the U.S. Department of Energy. A 240-volt Level 2 charger adds roughly 25 miles per hour and can usually charge a typical EV overnight, which is why most owners who drive daily install one.
• A Level 2 charger needs its own dedicated circuit, sized for the charger.
• Check whether your utility offers rebates or special EV rates, and whether your HOA has rules about installations.

Home generators

• Never plug a portable generator into a wall outlet to power the house. This is called backfeeding, and the Consumer Product Safety Commission calls it dangerous: it can energize utility lines and injure line workers or neighbors.
• To power home circuits safely, have an electrician install a transfer switch or approved interlock.
• Run portable generators outdoors only. Consumer Reports recommends placing them at least 20 feet from the house, with exhaust pointed away from windows and doors, because of carbon monoxide.
• Standby generators are installed permanently and connect through an automatic transfer switch.

Hot tubs, pools and outdoor equipment

Outdoor and water-related equipment has specific requirements for disconnects, GFCI protection, bonding and clearances. These rules exist to prevent shock, so this is work for a licensed electrician who knows your local code.

Permits

Most major electrical additions require a permit and inspection. A licensed electrician will usually pull the permit. Permitted work is inspected for safety and is easier to document when you sell the home.