How the EV chargers get their power, i.e., their power source, is an important consideration when deciding on the appropriate EV charger. The availability of 240v (residential supply) to various NEMA plug types gave rise to the widespread adoption and production of so-called plug-in EV chargers (also known as EVSEs).
What are plug-in EV chargers?
These are EV chargers (EVSEs) that get the power via a plug receptacle which is wired to a circuit in your panel breaker. These plug receptacles are typically mounted inside the garage or exterior to the garage.
What types of plug-in EV chargers are there?
Level 1 plug-in EV chargers will use mainly a NEMA 5-15 or NEMA 5-20 plug receptacle type.
Level 2 plug-in EV chargers will use mainly a NEMA 14-50 or NEMA 6-50 plug receptacle type.
What are the important considerations with plug-in EV chargers?
- The power should be 80% of the load. For example, a NEMA 14-50 on a 50 amp circuit breaker should run at 40 amps max. One should never pull 48 amps from a 50 amps circuit breaker. (a common problem I see is 14-50 on a 40 amp circuit, creating a malfunction in the EV charger at 40 amps. Our EV chargers are adjustable, and so to overcome they need to be set to 32 amps)
- If you are considering a plug-in charging station, never buy a station with a NEMA 10-30 or 10-50 plug. There is no safety earth ground connection to the vehicle.
- Ensure the use of a high-quality, industrial-grade plug these will be more durable for the longer continuous load.
- Discuss local electrical codes with your electricians related to the use of GFCI protection
What are hardwired EV chargers
Hardwired EV chargers do not use a plug receptacle. They are wired directly into the circuit breaker of your electrical panel. A hardwired charger allows for slightly higher amperage.
A common hardwired EV charger is 48 amps / 11.5 kWh compared to 40 amps for a plug-in EV charger. Also, if they are hardwired, they do not need GFCI protection. One disadvantage is that there is less flexibility in the location of your EV charger since they need to be hardwired close to the electrical panel. If moving, there is also less portability and more expense to move the charging station