EV Chargers & Electric Vehicle Hazards
Electric vehicles and chargers are now on jobsites, in shops, in parking garages and in homes. They bring high-voltage batteries, heavy electrical loads and a new kind of fire. Electricians, mechanics, tow operators and homeowners each need to know a few key rules.
- Electricians
- Mechanics
- Tow operators
- Homeowners
Photo: wall-mounted Level 2 EV charger on a dedicated circuit in a garage, with orange high-voltage cables visible on an EV battery pack in a shop
Charger levels
| Level | Power | Where |
|---|---|---|
| Level 1 | 120 volts, standard outlet | Homes; slow charging |
| Level 2 | 208–240 volts, dedicated circuit | Homes, workplaces, public parking |
| DC fast charging | Hundreds of volts DC, very high current | Highway stations, fleets |
Installing chargers
- Installation should be done by a qualified electrician, with a permit and inspection where required.
- Use a dedicated circuit sized for the charger’s continuous load.
- Follow the National Electrical Code’s EV charging rules, including ground-fault protection for receptacles used for charging.
- Make sure the panel and service can handle the added load.
At home
- Don’t charge with an ordinary extension cord or power strip; they can overheat and start fires.
- Don’t plug a Level 2 charger into a dryer or welder outlet with adapters unless it’s designed and installed for that use.
- Don’t use a damaged charging cable or connector.
- Don’t let warm or melted outlets go unchecked; call an electrician.
Working on or around EVs
- High-voltage cables are orange. EV batteries often run at 400 to 800 volts DC or more. Only trained technicians should work on high-voltage parts, following the maker’s shutdown procedure and wearing rated gloves.
- A quiet car may still be “on.” Confirm it’s off and in park, and keep the key fob away when working on it.
- Tow and lift EVs by the maker’s instructions; many can’t be towed with wheels on the ground, and lift points avoid the battery.
EV battery fires burn hot, give off toxic gases and can reignite hours or days later. A damaged, crashed or flooded EV (especially after saltwater flooding) should be parked outdoors, at least 50 feet from buildings and other vehicles. Call 911 for any smoke or hissing from the battery. See Battery Safety.
Quick checklist for shops
- Only trained techs touch orange high-voltage components
- Maker’s service disconnect procedure followed and verified
- Insulated gloves (rated and tested) and tools on hand
- Damaged EVs stored outdoors, away from buildings
- Fire plan includes EV battery fires
Standards & references
- OSHA: Electrical hazards
- U.S. DOE Alternative Fuels Data Center: EV charging
- NFPA 70 (National Electrical Code), Article 625: Electric vehicle power transfer systems
- See also: National Electrical Code · Diesel Mechanics
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