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Electric Vehicle Fueling Systems: EVFS

Michigan Department of Agriculture & Rural Development
 EVFS Information
August 7, 2023

 

In July, at the National Conference on Weights and Measures Annual Conference, regulators voted to move NIST Handbook 44, Section 3.40 Electric Vehicle Fueling Systems code from tentative to permanent.  This was voted into the Handbook as a tentative code in 2015 and permanent status will become effective January 1, 2023.

Regulators and industry worked together to enact the following amendments (highlighted) to the code to ensure no current devices in the field, or those to be deployed over the next 5 years, would be in conflict with the code;

S. Specifications 

S.2.7. Indication of Delivery. – The EVSE shall automatically show on its face the initial zero condition and the quantity delivered (up to the capacity of the indicating elements). 
[All DC EVSE are exempt from this requirement until January 1, 2028.]

N. Notes

N.5. Test of an EVSE System.

N.5.2. Accuracy Testing. – The testing methodology compares the total energy delivered in a transaction and the total cost charged as displayed/reported by the EVSE with that measured by the measurement standard. 

(b) For DC systems (see note):

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum deliverable amperes current (expressed as MDA) as determined from the digital communication message from the DC EVSE to the test standard for a total energy delivered of at least twice the minimum measured quantity (MMQ). 

(2) Accuracy test of the EVSE system at a load of not more than 10 % of the maximum deliverable amperes (expressed as MDA) as determined from the digital communication message from the DC EVSE to the test standard for a total energy delivered of at least the minimum measured quantity (MMQ). 

[All DC EVSE are exempt from this requirement until January 1, 2028.]

Note: For DC systems it is anticipated that an electric vehicle may be used as the test load. Under that circumstance, testing at the load presented by the vehicle shall be sufficient. 

T. Tolerances 

T.2. Load Test Tolerances. 

T.2.1. EVSE Load Test Tolerances. – The tolerances for EVSE load tests for are:

(a) Acceptance Tolerance: 1.0 %; and 
(b) Maintenance Tolerance: 2.0 %. 

[All DC EVSE are exempt from this requirement until January 1, 2028.]

 

Michigan Specific Criteria
Weights and Measures Act, Public Act 283 of 1964, as amended
Amended 2022, Effective March 29, 2023

http://legislature.mi.gov/doc.aspx?mcl-act-283-of-1964

 

 

This update incorporates, by reference, NIST Handbook 44, 2023 edition.  New Electric Vehicle Supply Equipment (EVSE) requirements;

- AC Devices installed after March 29, 2023

o Must be NTEP (or CTEP) approved
o Must be Placed-into-Service by a Michigan Registered Service Agency (RSA)
o Must meet all requirements of NIST Handbook 44, 2023 edition

-DC Devices installed after March 29, 2023

o Must be Placed-into-Service by an RSA
o Must meet the requirements of NIST Handbook 44, 2023 edition except for those exemptions listed on page 1

- AC Devices installed prior to March 29, 2023

o Exempt from NIST Handbook 44, 2023 edition requirements until January 1, 2028, with exception of the list below

-DC Devices installed prior to March 29, 2023

o Exempt from NIST Handbook 44, 2023 edition requirements until January 1, 2028, with exception of the list cited below

 

 

All devices, regardless of installation date, must meet the following NIST Handbook 44, 2023 edition requirements;

-S.2.6.EVSE Recorded Representations. – A receipt, either printed or electronic, providing the following information shall be available at the completion of all transactions:

- S.3.1. Metrological Components. – An EVSE measuring system shall be designed and constructed so that metrological components are adequately protected from environmental conditions likely to be detrimental to accuracy.  The system shall be designed to prevent undetected access to adjustment mechanisms and terminal blocks by providing for application of a physical security seal or an audit trail.
- S.3.2. Terminals. – The terminals of the EVSE system shall be arranged so that the possibility of short circuits while removing or replacing the cover, making connections, or adjusting the system, is minimized.
- S.4.1. Diversion of Measured Electricity. – No means shall be provided by which any measured electricity can be diverted from the measuring device.

o S.4.1.1. Unauthorized Disconnection. – Means shall be provided to automatically terminate the transaction in the event that there is an unauthorized break in the connection with the vehicle.

-UR.1.2.Connection Cord-Length. – An adequate means for cord management shall be in use when the cord exceeds 25 ft in length.

- UR.2. Installation Requirements.

o UR.2.1. Maximum Deliverable Current. – The marked maximum deliverable current shall not exceed the total capacity in amperes of the EVSE or the thermal overload protectors of the installation site.
o UR.2.2. Manufacturer’s Instructions. – An EVSE shall be installed in accordance with the manufacturer’s instructions, and the installation shall be sufficiently secure and rigid to maintain this condition.
o UR.2.3. Load Range. – An EVSE shall be installed so that the current and voltage will not exceed the rated maximum values over which the EVSE is designed to operate continuously within the specified accuracy.  Means to limit current and/or voltage shall be incorporated in the installation if necessary.
o UR.2.4. Regulation Conflicts and Permit Compliance. – If any provision of Section UR.2. Installation Requirements is less stringent than that required of a similar installation by the serving utility, the installation shall be in accordance with those requirements of the serving utility.  The installer of any EVSE shall obtain all necessary permits.
o UR.2.5. Responsibility, Unattended EVSE. – An unattended EVSE shall have clearly and conspicuously displayed thereon, or immediately adjacent thereto, adequate information detailing the name, address, and phone number of the local responsible party for the device.

- UR.3.4. EVSE in Operation. – The EVSE shall be permanently, plainly, and visibly identified so that it is clear which EVSE and connector is in operation.
- UR.3.5. Steps After Charging. – After delivery to a customer from a retail EVSE:

o (a) the EVSE shall be shut-off at the end of a charge, through an automatic interlock that prevents subsequent charging until the indicating elements and recording elements, if the EVSE is equipped and activated to record, have been returned to their zero positions; and
o (b) the vehicle connector shall not be returned to its starting position unless the zero set-back interlock is engaged or becomes engaged by the act of disconnecting from the vehicle or the act of returning the connector to the starting position.

In addition, any observable safety concern may result in the inspector removing the device from service.

Questions may be directed to the Weights and Measures program at (517) 655-8202.