EV Charger Installers
Electric vehicle (EV) chargers run for hours at high current, which is more demanding than most household loads. A poor installation can overheat wiring, damage panels and start fires. Installers need good electrical knowledge, permits and careful work, and many places require a licensed electrician.
- Electrical
- Residential
- Commercial
Charger levels
| Level | Typical supply | Notes |
|---|---|---|
| Level 1 | 120 V, 12 to 16 amps | Plugs into a standard outlet. Slowest. The outlet and circuit must be in good condition and not shared with other loads |
| Level 2 | 240 V, often 16 to 80 amps | Most common home and workplace chargers. Usually a dedicated circuit, plug-in or hardwired |
| DC fast charging | Hundreds of volts and high current, three-phase | Commercial equipment with high-voltage hazards. Only qualified workers should install and service it |
See EV Chargers for general safety and National Electrical Code for how the code is used.
The code that applies
- NEC Article 625 covers electric vehicle power transfer systems. It sets rules for equipment, wiring, overcurrent protection, disconnects, ventilation and protection from damage. Local jurisdictions adopt and amend specific editions, so use the edition your authority has adopted.
- Continuous load. An EV charger is considered a continuous load because it can run for three hours or more. The circuit and breaker must be sized at 125 percent of the charger’s continuous current. For example, a 32-amp charger needs a 40-amp circuit, and a 40-amp charger needs a 50-amp circuit.
- Listed equipment. Use chargers and parts listed for the purpose, such as to UL 2594 or UL 2202, and install them per the instructions. See Listed & Labeled Equipment.
- GFCI protection is required for outlets and, depending on the edition, for EV charging circuits. Many chargers have built-in ground-fault protection. Check the code.
- Permits and inspection are usually required. Utilities may also require notice or approval for large loads. See Building Permits & Inspections.
Planning the job
- Assess the electrical service. Do a load calculation to see whether the panel and service have capacity. A 200-amp panel may be full already. Options include upgrading the service, using a load management device or a smaller charger.
- Check the panel for condition, space, brand and any damage, rust or scorched parts. See Panel Clearance and Breakers & Fuses.
- Plan the route. Choose a shorter run, and think about wall mounting, conduit and distance. Long runs need larger wire to limit voltage drop.
- Choose the location. Mount the charger at the right height, protected from vehicle impact, weather and water, and where the cable can reach the car without being a trip hazard.
- Outdoor and wet locations need weatherproof, rated equipment and fittings. See Wet Locations.
Safe installation
- Turn off, lock out and test before you work in a panel. Treat all conductors as live until tested. See Lockout/Tagout and Testing for Absence of Voltage.
- Use the right wire gauge and insulation type for the amps, the run and the conditions.
- Tighten terminals to the specified torque with a calibrated torque tool. Loose connections are a leading cause of overheating.
- Use the correct breaker for the panel, and don’t double-tap or overload a breaker.
- Install a disconnecting means when required, and label it.
- Use conduit and fittings that suit the location, and protect cables from damage.
- Trenching and drilling: locate underground lines first. See Call 811, Underground Power Lines and Hidden Wiring.
- Work safely at height and on ladders. See Step Ladders.
- Wear arc-rated PPE as your employer requires when working on energized equipment. See Arc Flash & NFPA 70E.
- Don’t use an extension cord, adapter or power strip with an EV charger.
- Don’t connect to an old, damaged or ungrounded outlet.
- Don’t change the charger’s current settings beyond the circuit rating.
- Don’t skip the load calculation or the permit.
Testing and handover
- Test the circuit, ground, GFCI function and polarity. Run a charging session and check connections for heat after the first charge, if the procedure calls for it.
- Give the customer written instructions: how to plug in, how to reset, the circuit rating, warning signs of trouble (hot plug, burning smell, tripped breaker) and who to call.
- Tell them not to use damaged cables or cover the unit while charging, and to keep the cord from being a trip hazard. See Charging an Electric Vehicle at Home.
- Keep records and permit documents.
Commercial and fast chargers
Commercial installations can involve three-phase power, transformers, trenching, concrete pads and high-voltage DC equipment. These jobs need qualified electricians, a site plan, utility coordination and lockout, and follow the maker’s procedures. Do not open DC fast charger cabinets unless you are trained and authorized.
Installer checklist
- Load calculation done; panel capacity and condition checked
- Circuit sized at 125 percent of the continuous load; right wire and breaker
- Listed charger installed per instructions; GFCI and disconnect as required
- Terminals torqued; weatherproof fittings used outdoors
- Permit and inspection arranged; underground lines located
- Customer given instructions and the circuit rating
Standards & references
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