Subject Series: B-020

Weights and Measures Connection, Vol. 11, Issue 2 Page 1

First Certificate of Type Approval for Electric Vehicle Supply Equipment 

Issued by the California Division of Measurement Standards

Byline: Juana Williams (NIST OWM) and Kristin Macey (CA)

The California (CA) Department of Food and Agriculture Division of Measurement Standards (DMS) took an 

important first step in the recognition of Electric Vehicle Supply Equipment (EVSE) for commercial use in the U.S. 

On February 25, 2021, the CA DMS issued the first CA Type Evaluation Program (CTEP) Certificate of Approval to 

the manufacturer of a specific model of EVSE. An EVSE is a device or system designed and used specifically to 

transfer electrical energy to an electric vehicle (EV) through either a physical or wireless connection. EVSEs have 

been installed at various locations throughout the U.S. for the public to fuel their electric vehicles for a fee. With the 

issuance of the first type evaluation certificate by CA DMS to an EVSE, state and local officials in a number of 

jurisdictions across the country may soon begin routine inspections to ensure commercially-used EVSEs are accurate, 

well-constructed, properly designed and installed, and suited for use in commercial transactions. 

Most weights and measures jurisdictions in the U.S. require that commercial weighing or measuring devices such as 

gas pumps, grocery scales, and propane metering devices undergo a type evaluation before those devices can be used 

to buy or sell products and services. This includes EVSEs in fueling stations or parking lot facilities that are used to 

buy or sell electrical energy to fuel an EV. A certificate is issued to a device manufacturer when a specific model of 

weighing or measuring device has successfully completed rigorous evaluation to determine it conforms to a set of 

design and performance code requirements. This process takes place before the device is used commercially in the 

marketplace. 

In 2012, the NIST U.S. National Working Group on Electric Vehicle Fueling and Submetering began work on legal 

metrology standards for EVSE equipment and a corresponding method of sale. CA DMS was at the forefront of this 

work, joining this group of experts, comprised of state and local weight and measures officials, manufacturers, 

members of the electrical energy community, federal government agencies, and other technical experts to develop 

what was incorporated into NIST Handbooks 44 (EVSE equipment) and 130 (method of sale/signage) in 2015 and 

later into a NIST Examination Procedure Outline (field test procedures). CA DMS played a pivotal role in this process, 

not only bringing to the table its extensive expertise at the county and state levels, but also hosting the bulk of the 

Work Group meetings and championing the adoption of these standards across the country. This work serves as a 

great example of state and federal collaboration with stakeholders working together to build the weights and measures 

infrastructure to support this important alternative fueling application.

Except for a few types of devices regulated by specific Federal agencies, the regulatory authority for commercial 

weighing and measuring devices rests largely with state and local weights and measures jurisdictions. Most states 

adopt and enforce the provisions of NIST Handbooks 130 and 44 as the requirements for commercial weighing and 

measuring devices and practices in their states.

The first EVSE to receive CTEP approval met California Code of Regulations (CCR) requirements which are closely 

based on NIST Handbook 44 Section 3.40 Electric Vehicle Fueling Systems – Tentative Code. The CCR EVSE 

regulation was adopted by CA in 2019 and became effective on January 1, 2020. The CCR permissible errors for the 

EVSE’s delivery of electrical energy to an EV during type evaluation is ± 1.0 percent. Commercial EVSEs installed 

in California prior to certain installation dates do not have to comply with requirements. California has phase-in 

enforcement dates of:

• January 1, 2021 for all commercial EVSE AC Systems installed on or after January 1, 2021 making those 

devices fully subject to the regulation on January 1, 2021. 

• All commercial EVSE AC Systems installed prior to January 1, 2021 shall comply with the regulation by 

January 1, 2031. 

• All commercial EVSE DC Fast Charging Systems installed on or after January 1, 2023 will be fully subject 

to the regulation. 
Subject Series: B-020

Weights and Measures Connection, Vol. 11, Issue 2 Page 2

• All commercial EVSE DC Fast Charging Systems installed prior to January 1, 2023 shall comply with the 

regulation by January 1, 2033. 

The type evaluation process for EVSEs assesses the: (1) accuracy and correctness of the displayed and recorded 

transaction information when the EVSE is charging an EV or in the event of a power loss; (2) security placed on 

components that can alter measurement results; (3) marking of electrical rating information; (4) method of sale (by 

the kilowatt-hour) for deliveries of electrical energy; (5) charge(s) for other services connected with the fueling 

process based on time (if an EVSE has this feature); and (6) the likelihood the device maintains proper operations and 

settings under conditions of typical commercial use. When the U.S. National Type Evaluation Program (NTEP) 

administered by the National Conference on Weights and Measures (NCWM) begins accepting EVSEs for type 

evaluation those devices must comply with all requirements in NIST Handbook 44 Sections 1.10 General Code and 

3.40 Electric Vehicle Fueling Systems – Tentative Code and, where applicable, Section 5.55 Timing Devices.

With the adoption of requirements for EVSEs and the issuance of type evaluation certificates for these devices, the 

U.S. Weights and Measures community is moving into a new area of legal metrology. Instead of refueling a light 

duty vehicle with gasoline/diesel the trend is for battery/fuel cell vehicle fueling with alternative fuels such as 

electricity through Retail Electric Vehicle Fueling Systems (aka Electric Vehicle Supply Equipment (EVSE) or 

Electric Vehicle Chargers). State and local authorities have been operating programs set up to verify compliance of 

traditional fuel dispensers for over a century. Electrical energy commercial sales are new to most weights and 

measures jurisdictions except for California. For decades California county and state officials have routinely verified 

watthour type electric “submeters” used by landlords in apartment buildings, mobile home parks, campgrounds, 

marinas, and malls to bill tenants for power usage. Electricity metering and its verification has been under the domain 

of the utility companies and the public service/utility commissions, except for those “submeter” applications where 

weights and measures jurisdictions have exercised their regulatory authority. Nevertheless, public fueling of vehicles 

with electricity for a fee is new to the entire country and continues to grow. Once again California takes the lead on 

commercial electrical energy applications and there will be global benefits because of their actions. All signs point to 

more type approval certifications of EVSEs to come.