Overview

With electric vehicle charging becoming more and more prevalent, guidance was needed to calculate the minimum volt-ampere requirements for electric vehicle supply equipment (EVSE). Care was taken when adding the new requirements of Section 220.57 in the 2023 NEC. If these requirements were oversized, the added cost would be burdensome for installers of the equipment. As electric charging infrastructure increases in commonality, this new section adds all the required information the installer needs to install/inspect this equipment, and to ensure a code-compliant installation. It covers minimum requirements, and guidance on how to size the load for chargers that exceed this minimum.

Applying the 2023 Code

The 2023 NEC addresses the minimum volt-ampere ratings required for EVSE (electric vehicle supply equipment) in the newly added section 220.57. It specifies that the minimum load of 7200VA, or the nameplate rating of the equipment, whichever is greater, is to be used for the service load. This number was calculated on the basis of a 30 ampere, 240-volt, single phase circuit. This means that if a 5000 volt-ampere charger was selected for installation, the minimum load would have to be calculated at 7200VA. On the other hand, if a 14,400 volt-amp charger was selected for installation, the minimum load would 14,400VA. This new code addition ensures that new services will be able to supply a minimum of 7200VA for electric vehicle charging, even if a smaller unit is originally intended for installation. The code also provides the needed guidance for systems that are sized above this minimum requirement.

What’s New for the 2023 NEC?

2020 NEC

In the 2020 NEC Section 220.57 did not exist.

2023 NEC

In the 2023 NEC Section 220.57 read as follows (without informational notes):

220.57 Electric Vehicle Supply Equipment (EVSE) Load.

The EVSE load shall be calculated at either 7200 watts (volt-amperes) or the nameplate rating of the equipment, whichever is larger.