Code Change Summary: The code language on EVSE equipment ratings was restructured and revised.

In the 2023 NEC^®, Section 625.42 was revised to accommodate advancements in technology for electric vehicle supply equipment (EVSE).

Advancing EVSE technology has produced charging equipment where multiple chargers can be connected to an energy management system (EMS) that allow for a set amount of combined current draw for all EVSE connected to the system that will not exceed the feeder or branch circuit rating.

An example might be an EVSE system design where one branch circuit supplies three identical EV chargers incorporating an EMS capable of monitoring and limiting the cumulative current draw of all three connected EV chargers on the branch circuit. The branch circuit can be rated greater than the rating of any one of the three individual EV chargers in the system design, but the overall design would not permit any one EV charger from drawing more current than it is individually rated for.

The EMS ensures the current draw from each EV charger is adjusted based on demand to comply with the code requirements for the EVSE system installation.

Assume each EV charger is individually rated for 30-amps and all three EV chargers are supplied by the same shared individual branch circuit rated 100-amps. Also keep in mind Section 625.42 requires that EV charging is a continuous load and therefore 80% of the 100-amp branch circuit rating shall not be exceeded:

If only one EV charger is active, it can draw the maximum current of the branch circuit that the individual EV charger is rated for, which is 30-amps. If the EMS finds that two EV chargers are active, they can each draw 30-amps. If all three EV chargers are active, the EMS would need to manage the load so the combined load of all three EV chargers does not exceed 80% of the 100-amp branch circuit rating of 100-amps supplying the group of EVSE.

For the example above, if the load management control capabilities are an integral part of the listed EVSE, the EVSE would be marked to indicate that load management control is provided.

Additionally, some modern EVSE is designed with adjustable load ratings allowing EV chargers to be installed in occupancies having little remaining capacity for adding more loads.

In occupancies with limited remaining capacity for additional loads, installing a 30-or 40-amp EV charging circuit can push the service load calculation over the edge to the point that the service size needs to be upgraded. Some manufacturers solved this dilemma years ago by creating EVSE that can be adjusted to a lower setting to accommodate limited remaining load capabilities of an electric service.

In the 2023 NEC^®, Section 625.42 was revised as follows:

• The initial parent text in 625.42 was retained which still requires the EVSE to have sufficient rating to supply the load served and requires EV charging loads to be considered continuous.
• The previous language in the parent text of 625.42 permitting the EVSE load on a service or feeder to be sized in accordance with the product ratings was expanded to allow the overall rating of the installation to be limited through controls as permitted by 625.42(A) or (B).
• New Section 625.42(A) covers installations where an EMS in accordance with 750.30 provides load management of EVSE. For these installations, the maximum equipment load on a service and feeder shall be the maximum load permitted by the EMS. When one or more pieces of equipment are provided with an integral load management control, the system must be marked to indicate this control is provided.
• New Section 625.42(B) covers EVSE with restricted access to an ampere adjusting means complying with 750.30(C). If adjustments have an impact on the rating label, those changes must be in accordance with manufacturer’s instructions, and the adjusted rating must appear on the rating label with sufficient durability to withstand the environment involved.
• The previous language that restricted EVSE with adjustable settings to “fixed-in-place equipment only” has been deleted since cord-connected EVSE (not fixed-in-place) provided with adjustable settings can also be code compliant provided the EVSE complies with the same restrictions as fixed-in-place equipment.

Below is a preview of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2023 NEC^® edition of NFPA 70.