AC Level 2 EV Charger Electrical Wiring Knowledge Base

Canada/USA residential voltage is 120-240 volt
Condominium/Commercial/industrial buildings voltage is usually 120-208 volts
Consult local electrical codes for local requirements

Table 1 (J1772) AC Level 2 Chargers

Circuit Breaker (240V double-pole) Residential appliances Wire size, copper, AWG Max EV Charger size (continuous load *) Power @ 208 volts Power @ 240 volts
100 amps  - 2 (75°C rating) 80 amps 16.6 kilowatts 19.2 kilowatts
60 amps  - 4 48 amps 10 kilowatts 11.5 kilowatts
50 amps Electric Range 6 ampacity table 40 amps 8.3 kilowatts 9.6 kilowatts
40 amps  Electric Range, see this graphics 8 ampacity table 32 amps 6.6 kilowatts 7.7 kilowatts
30 amps Electric Dryer, see this graphics 10 24 amps 5.0 kilowatts 5.7 kilowatts
20 amps   12 16 amps 3.3 kilowatts 3.8 kilowatts

 

*Continuous load such as EV charging should only draw 80% of the circuit breaker's rating to avoid overheating and tripping.

DC chargers (Level 3) typically has much higher power ratings than Level 2 AC chargers. DC chargers are typically 50 kilowatts and up.

When choosing EV charger size, check with vehicle manufacturer's "acceptance rate" of the max kilowatts the vehicle can accept.

Rule of thumb: with current technology, assuming a 100% charging efficiency (in reality it is less), one kilowatt EVSE charging for one hour (=1 kWh) energy can deliver ≈ 5 to 6 km driving distance for typical small vehicles.

The many electrical plugs used by 240 volts AC EV chargers are confusing and frustrating. Fortunately, EVSV manufacturers seem to converge on the NEMA type 14-50 plug and NEMA 14-50R receptacles (up to 50 amps).

 

You can also choose a EVSE with hardwired version.