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Table of Contents

Page

Section 3.40. Electric Vehicle Fueling Systems – Tentative Code..............................3-157

A. Application ................................................................................................................................................ 3-157

A.1. General..............................................................................................................................................3-157

A.2. Exceptions.........................................................................................................................................3-157

A.3. Additional Code Requirements.........................................................................................................3-157

A.3.1. Electric Vehicle Supply Equipment (EVSE) with Integral Time-Measuring Devices........3-157

A.4. Type Evaluation................................................................................................................................3-157

S. Specifications............................................................................................................................................. 3-157

S.1. Primary Indicating and Recording Elements. ...................................................................................3-157

S.1.1. Electric Vehicle Supply Equipment (EVSE) ......................................................................3-157

S.1.2. EVSE Indicating Elements .................................................................................................3-158

S.1.3. EVSE Units.........................................................................................................................3-158

S.2. EVSE Operating Requirements. .......................................................................................................3-158

S.2.1. EVSE Return to Zero..........................................................................................................3-158

S.2.2. EVSE Indicator Zero Reset Mechanism. ............................................................................3-158

S.2.3. EVSE Provision for Power Loss.........................................................................................3-158

S.2.4. EVSE Indication of Unit Price and Equipment Capacity and Type of Voltage..................3-159

S.2.5. EVSE Money-Value Computations....................................................................................3-159

S.2.6. EVSE Recorded Representations........................................................................................3-160

S.2.7. Indication of Delivery.........................................................................................................3-160

S.2.8. Automatic Timeout – Pay-At-EVSE ....................................................................................3-160

S.3. Design of Measuring Elements and Measuring Systems. .................................................................3-160

S.3.1. Metrological Components...................................................................................................3-160

S.3.2. Terminals. ...........................................................................................................................3-161

S.3.3. Provision for Sealing...........................................................................................................3-161

S.3.4. Data Storage and Retrieval. ................................................................................................3-162

S.3.5. Temperature Range for System Components. ....................................................................3-162

S.4. Connections. .....................................................................................................................................3-163

S.4.1. Diversion of Measured Electricity. .....................................................................................3-163

S.4.2. Directional Control. ............................................................................................................3-163

S.5. Markings. ..........................................................................................................................................3-163

S.5.1. Location of Marking Information; EVSE. ..........................................................................3-163

S.5.2. EVSE Identification and Marking Requirements................................................................3-163

S.5.3. Abbreviations and Symbols. ...............................................................................................3-163

S.6. Printer. ..............................................................................................................................................3-163

S.6.1. Printed Receipt....................................................................................................................3-163

S.7. Totalizers for EVSE Systems............................................................................................................3-164

S.8. Minimum Measured Quantity (MMQ). ............................................................................................3-164

N. Notes........................................................................................................................................................... 3-164

N.1. No Load Test. ...................................................................................................................................3-164

N.2. Starting Load Test.............................................................................................................................3-164

N.3. Minimum Test Draft (Size)...............................................................................................................3-164

N.4. EVSE System Test Loads. ................................................................................................................3-164

N.5. Test of an EVSE System...................................................................................................................3-164

N.5.1. Performance Verification in the Field.................................................................................3-164

N.5.2. Accuracy Testing. ...............................................................................................................3-164
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N.6. Repeatability Tests............................................................................................................................3-165

T. Tolerances.................................................................................................................................................. 3-165

T.1. Tolerances, General. .........................................................................................................................3-165

T.2. Load Test Tolerances........................................................................................................................3-165

T.2.1. EVSE Load Test Tolerances...............................................................................................3-165

T.3. Repeatability. ....................................................................................................................................3-165

T.4. Tolerance Application in Type Evaluation Examinations for EVSEs. .............................................3-165

T.5. No Load Test. ...................................................................................................................................3-165

T.6. Starting Load.....................................................................................................................................3-165

UR. User Requirements...................................................................................................................................... 3-165

UR.1. Selection Requirements. ...................................................................................................................3-165

UR.1.1. Computing-Type Device; Retail EVSE. .............................................................................3-165

UR.1.2. Connection Cord-Length. ...................................................................................................3-166

UR.2. Installation Requirements. ................................................................................................................3-166

UR.2.1. Maximum Deliverable Current. ..........................................................................................3-166

UR.2.2. Manufacturer’s Instructions. ...............................................................................................3-166

UR.2.3. Load Range.........................................................................................................................3-166

UR.2.4. Regulation Conflicts and Permit Compliance.....................................................................3-166

UR.2.5. Responsibility, Unattended EVSE. .....................................................................................3-166

UR.3. Use of EVSE.....................................................................................................................................3-166

UR.3.1. Unit Price for Retail EVSE Devices. ..................................................................................3-166

UR.3.2. Return of Indicating and Recording Elements to Zero. ......................................................3-166

UR.3.3. EVSE Recorded Representations........................................................................................3-166

UR.3.4. EVSE in Operation. ............................................................................................................3-167

UR.3.5. Steps After Charging...........................................................................................................3-167

Appendix D. Definitions....................................................................................................................................... 3-168

alternating current (AC)...............................................................................................................................3-168

ampere... .....................................................................................................................................................3-168

audit trail......................................................................................................................................................3-168

calibration parameter. ..................................................................................................................................3-168

configuration parameter...............................................................................................................................3-168

creep............................................................................................................................................................3-168

current.........................................................................................................................................................3-168

direct current (DC).......................................................................................................................................3-168

electric vehicle, plug-in................................................................................................................................3-168

electric vehicle supply equipment (EVSE). .................................................................................................3-169

electricity as vehicle fuel. ............................................................................................................................3-169

energy... ......................................................................................................................................................3-169

energy flow. .................................................................................................................................................3-169

equipment, commercial................................................................................................................................3-169

event counter................................................................................................................................................3-169

event logger. ................................................................................................................................................3-169

EVSE field reference standard.....................................................................................................................3-169

face.............................................................................................................................................................3-169

hertz (Hz).....................................................................................................................................................3-169

megajoule (MJ)............................................................................................................................................3-169

kilowatt (kW)...............................................................................................................................................3-170
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kilowatt-hour (kWh). ...................................................................................................................................3-170

load, full.......................................................................................................................................................3-170

load, light.....................................................................................................................................................3-170

master meter, electric...................................................................................................................................3-170

meter, electricity. .........................................................................................................................................3-170

metrological components.............................................................................................................................3-170

nationally recognized testing laboratory (NRTL)........................................................................................3-170

nonresettable totalizer..................................................................................................................................3-170

ohm (Ω). ......................................................................................................................................................3-170

percent registration. .....................................................................................................................................3-170

power factor (PF).........................................................................................................................................3-171

primary indicating or recording elements. ...................................................................................................3-171

recorded representation................................................................................................................................3-171

recording element. .......................................................................................................................................3-171

remote configuration capability. ..................................................................................................................3-171

retail device..................................................................................................................................................3-171

serving utility...............................................................................................................................................3-171

starting load. ................................................................................................................................................3-171

submeter.......................................................................................................................................................3-171

test accuracy – in-service.............................................................................................................................3-171

test amperes (TA). .......................................................................................................................................3-171

thermal overload protector...........................................................................................................................3-171

unit price......................................................................................................................................................3-172

vehicle connector.........................................................................................................................................3-172

vehicle coupler.............................................................................................................................................3-172

vehicle inlet..................................................................................................................................................3-172

volt.............................................................................................................................................................3-172

watt...... ......................................................................................................................................................3-172

watthour (Wh)..............................................................................................................................................3-172
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Section 3.40. Electric Vehicle Fueling Systems – Tentative Code

This tentative code has a trial or experimental status and is not intended to be enforced. The requirements are designed 

for study prior to the development and adoption of a final code. Officials wanting to conduct an official examination 

of an Electric Vehicle Supply Equipment (EVSE) or system are advised to see paragraph G-A.3. Special and 

Unclassified Equipment.

(Tentative Code Added 2015)

A. Application

A.1. General. – This code applies to devices, accessories, and systems used for the measurement of electricity

dispensed in vehicle fuel applications wherein a quantity determination or statement of measure is used wholly or 

partially as a basis for sale or upon which a charge for service is based.

A.2. Exceptions. – This code does not apply to:

(a) The use of any measure or measuring device owned, maintained, and used by a public utility or municipality

only in connection with measuring electricity subject to the authority having jurisdiction such as the Public 

Utilities Commission.

(b) Electric Vehicle Supply Equipment (EVSEs) used solely for dispensing electrical energy in connection with 

operations in which the amount dispensed does not affect customer charges or compensation.

(c) The wholesale delivery of electricity.

A.3. Additional Code Requirements. – In addition to the requirements of this code, Electric Fueling Systems shall 

meet the requirements of Section 1.10. General Code.

A.3.1. Electric Vehicle Supply Equipment (EVSE) with Integral Time-Measuring Devices. – An EVSE

that is used for both the sale of electricity as vehicle fuel and used to measure time during which services

(e.g., vehicle parking) are received. These devices shall also meet the requirements of Section 5.55. Timing 

Devices.

A.4. Type Evaluation. – The National Type Evaluation Program (NTEP) will accept for type evaluation only those 

EVSEs that comply with all requirements of this code and have received safety certification by a nationally recognized 

testing laboratory (NRTL).

S. Specifications

S.1. Primary Indicating and Recording Elements.

S.1.1. Electric Vehicle Supply Equipment (EVSE). – An EVSE used to charge electric vehicles shall be of 

the computing type and shall indicate the electrical energy, the unit price, and the total price of each transaction.

(a) EVSEs capable of applying multiple unit prices over the course of a single transaction shall also be 

capable of indicating the start and stop time, the total quantity of energy delivered, the unit price, and 

the total price for the quantity of energy delivered during each discrete phase corresponding to one of 

the multiple unit prices.

(b) EVSEs capable of applying additional fees for time-based and other services shall also be capable of 

indicating the total time measured; the unit price(s) for the additional time-based service(s); the total 

computed price(s) for the time measured; and the total transaction price, including the total price for the 

energy and all additional fees.
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S.1.2. EVSE Indicating Elements. – An EVSE used to charge electric vehicles shall include an indicating 

element that accumulates continuously and displays, for a minimum of 15 seconds at the activation by the user 

and at the start and end of the transaction, the correct measurement results relative to quantity and total price. 

Indications shall be clear, definite, accurate, and easily read under normal conditions of operation of the device. 

All indications and representations of electricity sold shall be clearly identified and separate from other timebased fees indicated by an EVSE that is used for both the sale of electricity as vehicle fuel and the sale of other 

separate time-based services (e.g., vehicle parking).

S.1.2.1. Multiple EVSEs Associated with a Single Indicating Element. – A system with a single 

indicating element for two or more EVSEs shall be provided with means to display information from the 

individual EVSE(s) selected or displayed, and shall be provided with an automatic means to indicate clearly 

and definitely which EVSE is associated with the displayed information.

S.1.3. EVSE Units. 

S.1.3.1. EVSE Units of Measurement. – EVSE units used to charge electric vehicles shall be indicated

and recorded in megajoules (MJ) or kilowatt-hours (kWh) and decimal subdivisions thereof.

S.1.3.2. EVSE Value of Smallest Unit. – The value of the smallest unit of indicated delivery by an EVSE, 

and recorded delivery if the EVSE is equipped to record, shall be 0.005 MJ or 0.001 kWh.

S.1.3.3. Values Defined. – Indicated values shall be adequately defined by a sufficient number of figures,

words, symbols, or combinations thereof. An indication of “zero” shall be a zero digit for all displayed digits 

to the right of the decimal mark and at least one to the left.

S.2. EVSE Operating Requirements.

S.2.1. EVSE Return to Zero. 

(a) The primary indicating and the primary recording elements of an EVSE used to charge electric vehicles, 

if the EVSE is equipped to record, shall be provided with a means for readily returning the indication to 

zero either automatically or manually.

(b) It shall not be possible to return primary indicating elements, or primary recording elements, beyond the 

correct zero position.

S.2.2. EVSE Indicator Zero Reset Mechanism. – The reset mechanism for the indicating element of an EVSE

used to charge electric vehicles shall not be operable during a transaction. Once the zeroing operation has begun, 

it shall not be possible to indicate a value other than: the latest measurement; “all zeros;” blank the indication; or 

provide other indications that cannot be interpreted as a measurement during the zeroing operation.

S.2.3. EVSE Provision for Power Loss. 

S.2.3.1. Transaction Information. – In the event of a power loss, the information needed to complete 

any transaction (i.e., delivery is complete and payment is settled) in progress at the time of the power loss

(such as the quantity and unit price, or sales price) shall be determinable through one of the means listed 

below or the transaction shall be terminated without any charge for the electrical energy transfer to the 

vehicle:

(a) at the EVSE;

(b) at the console, if the console is accessible to the customer;

(c) via on site internet access; or
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(d) through toll-free phone access.

For EVSEs in parking areas where vehicles are commonly left for extended periods, the information needed 

to complete any transaction in progress at the time of the power loss shall be determinable through one of the 

above means for at least eight hours.

S.2.3.2. Transaction Termination. – In the event of a power loss, either: 

(a) the transaction shall terminate at the time of the power loss; or 

(b) the EVSE may continue charging without additional authorization if the EVSE is able to determine 

it is connected to the same vehicle before and after the supply power outage. 

In either case, there must be a clear indication on the receipt provided to the customer of the interruption, 

including the date and time of the interruption along with other information required under S.2.6. EVSE 

Recorded Representations.

S.2.3.3. User Information. – The EVSE memory, or equipment on the network supporting the EVSE,

shall retain information on the quantity of fuel dispensed and the sales price totals during power loss.

S.2.4. EVSE Indication of Unit Price and Equipment Capacity and Type of Voltage. 

S.2.4.1. Unit Price. – An EVSE shall be able to indicate on each face the unit price at which the EVSE is 

set to compute or to dispense at any point in time during a transaction.

S.2.4.2. Equipment Capacity and Type of Voltage. – An EVSE shall be able to conspicuously indicate

on each face the maximum rate of energy transfer (i.e., maximum power) and the type of current associated 

with each unit price offered (e.g., 7 kW AC, 25 kW DC, etc.).

S.2.4.3. Selection of Unit Price. – When electrical energy is offered for sale at more than one unit price 

through an EVSE, the selection of the unit price shall be made prior to delivery through a deliberate action 

of the purchaser to select the unit price for the fuel delivery. Except when the conditions for variable price 

structure have been approved by the customer prior to the sale, a system shall not permit a change to the unit 

price during delivery of electrical energy.

Note: When electrical energy is offered at more than one unit price, selection of the unit price may be through the 

deliberate action of the purchaser: 1) using controls on the EVSE; 2) through the purchaser’s use of personal or vehiclemounted electronic equipment communicating with the system; or 3) verbal instructions by the customer.

S.2.4.4. Agreement Between Indications. – All quantity, unit price, and total price indications within a 

measuring system shall agree for each transaction.

S.2.5. EVSE Money-Value Computations. – An EVSE shall compute the total sales price at any 

single-purchase unit price for which the electrical energy being measured is offered for sale at any delivery 

possible within either the measurement range of the EVSE or the range of the computing elements, whichever is 

less.

S.2.5.1. Money-Value Divisions Digital. – An EVSE with digital indications shall comply with the 

requirements of paragraph G-S.5.5. Money-Values, Mathematical Agreement, and the total price 

computation shall be based on quantities not exceeding 0.5 MJ or 0.1 kWh.

S.2.5.2. Auxiliary Elements. – If a system is equipped with auxiliary indications, all indicated money 

value and quantity divisions of the auxiliary element shall be identical to those of the primary element. 
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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:

(a) the total quantity of the energy delivered with unit of measure;

(b) the total computed price of the energy sale;

(c) the unit price of the energy, and for systems capable of applying multiple unit prices for energy during 

a single transaction, the following additional information is required:

(1) the start and stop time of each phase during which one of the multiple unit prices was applied;

(2) the unit price applied during each phase;

(3) the total quantity of energy delivered during each phase;

(4) the total purchase price for the quantity of energy delivered during each phase;

(d) the maximum rate of energy transfer (i.e., maximum power) and type of current (e.g., 7 kW AC, 

25 kW DC, etc.);

(e) any additional separate charges included in the transaction (e.g., charges for parking time) including:

(1) the time and date when the service begins and the time and date when the service ends; or the total 

time interval purchased, and the time and date that the service either begins or ends;

(2) the unit price applied for the time-based service;

(3) the total purchase price for the quantity of time measured during the complete transaction; 

(f) the final total price of the complete transaction including all items;

(g) the unique EVSE identification number;

(h) the business name; and

(i) the business location.

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).

S.2.8. Automatic Timeout – Pay-At-EVSE. – Once an EVSE has been authorized, it must deauthorize within 

two minutes if not activated. Reauthorization of the EVSE must be performed before any electrical energy is 

delivered and/or timing charges assessed. If the time limit to deauthorize the EVSE is programmable, it shall not 

accept an entry greater than two minutes. 

[Nonretroactive as of January 1, 2020]

(Added 2019)

S.3. Design of Measuring Elements and Measuring Systems.

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.
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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.3.3. Provision for Sealing. – For devices and systems in which the configuration or calibration parameters 

can be changed by use of a removable digital storage device, security shall be provided for those parameters as 

specified in G-S.8.2. Devices and Systems Adjusted Using Removable Digital Storage Devices. For parameters 

adjusted using other means, the following applies.

Adequate provision shall be made for an approved means of security (e.g., data change audit trail) or physically 

applying security seals in such a manner that no adjustment can be made of:

(a) each individual measurement element;

(b) any adjustable element for controlling voltage or current when such control tends to affect the accuracy 

of deliveries;

(c) any adjustment mechanism that corrects or compensates for energy loss between the system and vehicle 

connection; and

(d) any metrological parameter that detrimentally affects the metrological integrity of the EVSE or system.

When applicable, the adjusting mechanism shall be readily accessible for purposes of affixing a security seal. 

Audit trails shall use the format set forth in Table S.3.3. Categories of Device and Methods of Sealing.

(Amended 2019)
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Table S.3.3.

Categories of Device and Methods of Sealing

Categories of Device Method of Sealing

Category 1: No remote configuration capability. Seal by physical seal or two event counters: one for 

calibration parameters and one for configuration 

parameters.

Category 2: Remote configuration capability, but 

access is controlled by physical hardware. 

The device shall clearly indicate that it is in the remote 

configuration mode and record such message if 

capable of printing in this mode or shall not operate 

while in this mode.

The hardware enabling access for remote 

communication must be on-site. The hardware must 

be sealed using a physical seal or an event counter for 

calibration parameters and an event counter for 

configuration parameters. The event counters may be 

located either at the individual measuring EVSE or at 

the system controller; however, an adequate number of 

counters must be provided to monitor the calibration 

and configuration parameters of the individual EVSEs 

at a location. If the counters are located in the system 

controller rather than at the individual EVSE, means 

must be provided to generate a copy of the information 

through an on-site device; this information may be 

provided electronically in lieu of or in addition to a 

hard copy at the time of inspection.

Category 3: Remote configuration capability access 

may be unlimited or controlled through a software 

switch (e.g., password).

The device shall clearly indicate that it is in the remote 

configuration mode and record such message if 

capable of printing in this mode or shall not operate 

while in this mode.

An event logger is required in the device; it must 

include an event counter (000 to 999), the parameter 

ID, the date and time of the change, and the new value 

of the parameter. The event logger information may 

be provided electronically in lieu of or in addition to a 

hard copy at the time of inspection, provided the event 

logger information is retained in the system for future 

reference. The event logger shall have a capacity to 

retain records equal to 10 times the number of sealable 

parameters in the EVSE, but not more than 1000 

records are required. (Note: Does not require 1000 

changes to be stored for each parameter.)

(Amended 2021)

S.3.4. Data Storage and Retrieval.

(a) EVSE data accumulated and indicated shall be unalterable and accessible.

(b) Values indicated or stored in memory shall not be affected by electrical, mechanical, or temperature 

variations, radio-frequency interference, power failure, or any other environmental influences to the 

extent that accuracy is impaired.

(c) Memory and/or display shall be recallable for a minimum of three years. A replaceable battery shall not 

be used for this purpose.

S.3.5. Temperature Range for System Components. – EVSEs shall be accurate and correct over the 

temperature range of – 40 °C to + 85 °C (− 40 °F to + 185 °F). If the system or any measuring system components 

are not capable of meeting these requirements, the temperature range over which the system is capable shall be 

stated on the NTEP CC, marked on the EVSE, and installations shall be limited to the narrower temperature 

limits.
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S.4. Connections.

S.4.1. Diversion of Measured Electricity. – No means shall be provided by which any measured electricity

can be diverted from the measuring device.

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.

S.4.2. Directional Control. – If a reversal of energy flow could result in errors that exceed the tolerance for 

the minimum measured quantity, effective means, automatic in operation to prevent or account for the reversal of 

flow shall be properly installed in the system. (See N.3. Minimum Test Draft [Size])

S.5. Markings. – The following identification and marking requirements are in addition to the requirements of 

Section 1.10. General Code, paragraph G-S.1. Identification.

S.5.1. Location of Marking Information; EVSE. – The marking information required in General Code, 

paragraph G-S.1. Identification shall appear as follows:

(a) within 60 cm (24 in) to 150 cm (60 in) from ground level; and

(b) on a portion of the EVSE that cannot be readily removed or interchanged (e.g., not on a service access 

panel).

S.5.2. EVSE Identification and Marking Requirements. – In addition to all the marking requirements of 

Section 1.10. General Code, paragraph G-S.1. Identification, each EVSE shall have the following information 

conspicuously, legibly, and indelibly marked:

(a) voltage rating;

(b) maximum current deliverable;

(c) type of current (AC or DC or, if capable of both, both shall be listed);

(d) minimum measured quantity (MMQ); and

(e) temperature limits, if narrower than and within – 40 °C to + 85 °C (− 40 °F to + 185 °F).

(Amended 2021)

S.5.3. Abbreviations and Symbols. – The following abbreviations or symbols may appear on an EVSE 

system.

(a) VAC = volts alternating current;

(b) VDC = volts direct current;

(c) MDA = maximum deliverable amperes;

(d) J = joule.

S.6. Printer. – When a system is equipped with means for printing the measured quantity, the printed information 

must agree with the indications on the EVSE for the transaction and the printed values shall be clearly defined.

S.6.1. Printed Receipt. – Any delivered, printed quantity shall include an EVSE identification number that 

uniquely identifies the EVSE from all other EVSEs within the seller’s facility, the time and date, and the name of 

the seller. This information may be printed by the EVSE system or pre-printed on the ticket.
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S.7. Totalizers for EVSE Systems. – EVSE systems shall be designed with a nonresettable totalizer for the quantity 

delivered through each separate measuring device. Totalizer information shall be adequately protected and 

unalterable. Totalizer information shall be provided by the system and readily available on site or via on site internet 

access.

S.8. Minimum Measured Quantity (MMQ). – The minimum measured quantity shall satisfy the conditions of use 

of the measuring system as follows:

(a) Measuring systems shall have a minimum measured quantity not exceeding 2.5 MJ or 0.5 kWh.

N. Notes

N.1. No Load Test. – A no load test may be conducted on an EVSE measuring system by applying rated voltage to 

the system under test and no load applied.

N.2. Starting Load Test. – A system starting load test may be conducted by applying rated voltage and 0.5-ampere 

load.

N.3. Minimum Test Draft (Size). – Full and light load tests shall require test of the EVSE System for a delivery of 

the minimum measured quantity as declared by the manufacturer.

N.4. EVSE System Test Loads. – EVSE measuring system testing shall be accomplished by connecting the test 

load and test standard at the point where the fixed cord is connected to the vehicle. Losses in the cord between the 

EVSE under test and the test standard should be automatically corrected for in the EVSE quantity indication for direct 

comparison to the test standard and also while the EVSE is in normal operation. For EVSEs that require a customersupplied cord, system testing shall be accomplished by connecting the test load and test standard at the point where 

the customer’s cord is connected to the EVSE.

N.5. Test of an EVSE System.

N.5.1. Performance Verification in the Field. – Testing in the field is intended to validate the transactional

accuracy of the EVSE system. The following testing is deemed sufficient for a field validation.

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.

(a) For AC systems:

(1) Accuracy test of the EVSE system at a load of not less than 85 % of the maximum deliverable 

amperes (expressed as MDA) as determined from the pilot signal for a total energy delivered of at 

least twice the minimum measured quantity (MMQ). If the MDA would result in maximum 

deliverable power of greater than 7.2 kW, then the test may be performed at 7.2 kW.

(2) Accuracy test of the EVSE system at a load of not greater than 10 % of the maximum deliverable 

amperes (expressed as MDA) as determined from the pilot signal for a total energy delivered of at 

least the minimum measured quantity (MMQ).

(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).
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(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).

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.

N.6. Repeatability Tests. – Tests for repeatability shall include a minimum of three consecutive tests at the same 

load, similar time period, etc., and be conducted under conditions where variations in factors are reduced to minimize 

the effect on the results obtained.

T. Tolerances

T.1. Tolerances, General.

(a) The tolerances apply equally to errors of underregistration and errors of overregistration.

(b) The tolerances apply to all deliveries measured at any load within the rated measuring range of the EVSE.

(c) Where instrument transformers or other components are used, the provisions of this section shall apply to 

all system components.

T.2. Load Test Tolerances.

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

(a) Acceptance Tolerance: 1.0 %; and 

(b) Maintenance Tolerance: 2.0 %.

T.3. Repeatability. – When multiple load tests are conducted at the same load condition, the range of the load test 

results shall not exceed 25 % of the absolute value of the maintenance tolerance and the results of each test shall be 

within the applicable tolerance.

T.4. Tolerance Application in Type Evaluation Examinations for EVSEs. – For type evaluation examinations, 

the acceptance tolerance values shall apply under the following conditions:

(a) at any temperature, voltage, load, and power factor within the operating range of the EVSE, and

(b) regardless of the influence factors in effect at the time of the conduct of the examination, and

(c) for all quantities greater than the minimum measured quantity.

T.5. No Load Test. – An EVSE measuring system shall not register when no load is applied. 

T.6. Starting Load. – An EVSE measuring system shall register a starting load test at a 0.5 ampere (A) load.

UR. User Requirements

UR.1. Selection Requirements.

UR.1.1. Computing-Type Device; Retail EVSE. – An EVSE used to charge electric vehicles shall be of the 

computing type and shall indicate the electrical energy, the unit price, and the total price of each delivery.
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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.

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.

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.

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.

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.

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. Use of EVSE.

UR.3.1. Unit Price for Retail EVSE Devices. – The unit price at which the EVSE is set to compute shall be 

conspicuously displayed or posted on the face of the retail EVSE used in direct sale.

UR.3.2. Return of Indicating and Recording Elements to Zero. – The primary indicating elements (visual)

and the primary recording elements shall be returned to zero immediately before each transaction. 

UR.3.3. EVSE Recorded Representations. – A receipt, either printed or electronic, providing the following 

information shall be available at the completion of all transactions:

(a) the total quantity of the energy delivered with unit of measure;

(b) the total computed price of the energy sale;

(c) the unit price of the energy; and for systems capable of applying multiple unit prices for energy during 

a single transaction, the following additional information is required:

(1) the start and stop time of each phase during which one of the multiple unit prices was applied;

(2) the unit price applied during each phase;

(3) the total quantity of energy delivered during each phase;

(4) the total purchase price for the quantity of energy delivered during each phase;

(d) the maximum rate of energy transfer (i.e., maximum power) and type of current (e.g., 7 kW AC, 

25 kW DC, etc.);

(e) any additional separate charges included in the transaction (e.g., charges for parking time) including:
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(1) the time and date when the service begins and the time and date when the service ends; or the total 

time interval purchased, and the time and date that the service either begins or ends;

(2) the unit price applied for the time-based service;

(3) the total purchase price for the quantity of time measured during the complete transaction; 

(f) the final total price of the complete transaction including all items;

(g) the unique EVSE identification number;

(h) the business name; and

(i) the business location.

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:

(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

(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.
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Appendix D. Definitions 

The following includes new definitions to address Electric Vehicle Fueling Systems. Also included are those 

definitions currently found in Appendix D that are intended to apply to these systems. The specific code(s) to which 

each definition applies is shown in [brackets] at the end of the definition. Definitions for the General Code [1.10] 

apply to all codes in Handbook 44.

A

alternating current (AC). – An electric current that reverses direction in a circuit at regular intervals. [3.40]

ampere. – The practical unit of electric current. It is the quantity of current caused to flow by a potential difference 

of one volt through a resistance of one ohm. One ampere (A) is equal to the flow of one coulomb of charge per second.

One coulomb (C) is the unit of electric charge equal in magnitude to the charge of 6.24 × 1018 electrons. [3.40]

audit trail. – An electronic count and/or information record of the changes to the values of the calibration or 

configuration parameters of a device. [1.10, 2.20, 2.21, 2.24, 3.30, 3.37, 3.39, 3.40, 5.56(a)]

(Added 1993)

C

calibration parameter. – Any adjustable parameter that can affect measurement or performance accuracy and, due 

to its nature, needs to be updated on an ongoing basis to maintain device accuracy (e.g., span adjustments, linearization 

factors, and coarse zero adjustments). [2.20, 2.21, 2.24, 3.30, 3.37, 3.39, 3.40, 5.56(a)]

(Added 1993)

configuration parameter. – Any adjustable or selectable parameter for a device feature that can affect the accuracy 

of a transaction or can significantly increase the potential for fraudulent use of the device and, due to its nature, needs 

to be updated only during device installation or upon replacement of a component (e.g., division value [increment], 

sensor range, and units of measurement). [2.20, 2.21, 2.24, 3.30, 3.37, 3.40, 5.56(a)]

(Added 1993)

creep. – A continuous apparent measurement of energy indicated by a system with operating voltage applied and no 

power consumed (load terminals open circuited). [3.40]

current. – The rate of the flow of electrical charge past any one point in a circuit. The unit of measurement is amperes

(A) or coulombs (C) per second. [3.40]

D

direct current (DC). – An electric current that flows in one direction. [3.40]

E

electric vehicle, plug-in. – A vehicle that employs electrical energy as a primary or secondary mode of propulsion. 

Plug-in electric vehicles may be all-electric vehicles (EV’s) or plug-in hybrid electric vehicles (PHEV’s). All-electric 

vehicles are powered by an electric motor and battery at all times. All-electric vehicles may also be called batteryelectric vehicles (BEV’s). Plug-in hybrid electric vehicles employ both an electric motor and an internal combustion 

engine that consumes either conventional or alternative fuel or a fuel cell. In a parallel type hybrid-electric vehicle, 

either the electric motor or the engine may propel the vehicle. In a series type hybrid-electric vehicle, the engine or 

fuel cell generates electricity that is then used by the electric motor to propel the vehicle. EV’s, BEV’s, and PHEV’s

are capable of receiving and storing electricity via connection to an external electrical supply. Not all hybrid-electric 

vehicles are of the plug-in type. Hybrid-electric vehicles that do not have the capability to receive electrical energy 
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from an external supply (HEV’s) generate electrical energy onboard with the internal combustion engine, regenerative 

braking, or both. [3.40]

electric vehicle supply equipment (EVSE). – A device or system designed and used specifically to transfer electrical 

energy to an electric vehicle, either as charge transferred via physical or wireless connection, by loading a fully charged 

battery, or by other means. [3.40]

electricity as vehicle fuel. – Electrical energy transferred to and/or stored onboard an electric vehicle primarily for 

the purpose of propulsion. [3.40]

energy. – The integral of active power with respect to time. [3.40]

energy flow. – The flow of energy between line and load terminals (conductors) of an electricity system. Flow from 

the line to the load terminals is considered energy delivered. Energy flowing in the opposite direction (i.e., from the 

load to line terminals) is considered as energy received. [3.40]

equipment, commercial. – Weights, measures, and weighing and measuring devices, instruments, elements, and 

systems or portion thereof, used or employed in establishing the measurement or in computing any basic charge or 

payment for services rendered on the basis of weight or measure. As used in this definition, measurement includes 

the determination of size, quantity, value, extent, area, composition (limited to meat and poultry), constituent value 

(for grain), or measurement of quantities, things, produce, or articles for distribution or consumption, purchased, 

offered, or submitted for sale, hire, or award. [1.10, 2.20, 2.21, 2.22, 2.24, 3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.38, 3.40, 

4.40, 5.51, 5.56.(a), 5.56.(b), 5.57, 5.58, 5.59]

(Added 2008)

event counter. – A nonresettable counter that increments once each time the mode that permits changes to sealable 

parameters is entered and one or more changes are made to sealable calibration or configuration parameters of a 

device. [2.20, 2.21, 3.30, 3.37, 3.39, 3.40, 5.54, 5.56(a), 5.56(b), 5.57]

(Added 1993)

event logger. – A form of audit trail containing a series of records where each record contains the number from the event 

counter corresponding to the change to a sealable parameter, the identification of the parameter that was changed, the time 

and date when the parameter was changed, and the new value of the parameter. [2.20, 2.21, 3.30, 3.37, 3.39, 3.40, 5.54, 

5.56(a), 5.56(b), 5.57]

(Added 1993)

EVSE field reference standard. – A portable apparatus that is traceable to NIST and is used as a standard to test 

EVSEs in commercial applications. This instrument is also known as a portable standard or working standard. [3.40]

F

face. – That portion of a computing-type pump or dispenser which displays the actual computation of price per unit, 

delivered quantity, and total sale price. In the case of some electronic displays, this may not be an integral part of the 

pump or dispenser. [3.30, 3.40]

(Added 1987)

H

hertz (Hz). – Frequency or cycles per second. One cycle of an alternating current or voltage is one complete set of 

positive and negative values of the current or voltage. [3.40]

J

megajoule (MJ). – An SI unit of energy equal to 1 000 000 joules (J). [3.40]
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K

kilowatt (kW). – A unit of power equal to 1000 watts (W). [3.40]

kilowatt-hour (kWh). – A unit of energy equal to 1000 watthours (W h). [3.40]

L

load, full. – A test condition with rated voltage, current at 100 % of test amps level, and power factor of 1.0. [3.40]

load, light. – A test condition with rated voltage, current at 10 % of test amps level, and power factor of 1.0. [3.40]

M

master meter, electric. – An electric watthour meter owned, maintained, and used for commercial billing purposes 

by the serving utility. All the electric energy served to a submetered service system is recorded by the master meter.

[3.40]

meter, electricity. – An electric watthour meter. [3.40]

metrological components. – Elements or features of a measurement device or system that perform the measurement 

process or that may affect the final quantity determination or resulting price determinations. This includes accessories 

that can affect the validity of transactions based upon the measurement process. The measurement process includes 

determination of quantities; the transmission, processing, storage, or other corrections or adjustments of measurement 

data or values; and the indication or recording of measurement values or other derived values such as price or worth 

or charges. [3.40]

minimum measured quantity (MMQ). – The smallest quantity delivered for which the measurement is to within the 

applicable tolerances for that system. [3.37, 3.39, 3.40]

(Added to Tentative Code 2021)

N

nationally recognized testing laboratory (NRTL). – A laboratory that conducts testing and certification that is 

recognized by the Occupational Safety and Health Administration (OSHA). [3.40] 

nonresettable totalizer. – An element interfaced with the measuring or weighing element that indicates the 

cumulative registration of the measured quantity with no means to return to zero. [3.30, 3.37, 3.39, 3.40]

O

ohm (Ω). – The practical unit of electric resistance that allows one ampere of current to flow when the impressed 

potential is one volt. [3.40]

P

percent registration. – Percent registration is calculated as follows:

100 Wh measured by EVSE Percent Registration Wh measured by STANDARD= ×

[3.40]
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power factor (PF). – The ratio of “active power” to “apparent power” in an AC circuit. It describes the efficient use 

of available power. [3.40]

primary indicating or recording elements. – The term “primary” is applied to those principal indicating (visual) 

elements and recording elements that are designed to, or may, be used by the operator in the normal commercial use 

of a device. The term “primary” is applied to any element or elements that may be the determining factor in arriving 

at the sale representation when the device is used commercially. (Examples of primary elements are the visual 

indicators for meters or scales not equipped with ticket printers or other recording elements and both the visual 

indicators and the ticket printers or other recording elements for meters or scales so equipped.) The term “primary” 

is not applied to such auxiliary elements as, for example, the totalizing register, or predetermined-stop mechanism on 

a meter or the means for producing a running record of successive weighing operations, these elements being 

supplementary to those that are the determining factors in sales representations of individual deliveries or weights. 

(See “indicating element” and “recording element.”). [1.10, 3.40]

R

recorded representation. – The printed, electronically recorded, or other representation that retains a copy of the 

quantity and any other required information generated by a weighing or measuring device. [1.10, 3.40]

recording element. – An element incorporated, connected to, or associated with a weighing or measuring device by 

means of which its performance relative to quantity or money value is permanently recorded in a printed or electronic 

form. [1.10, 3.40]

remote configuration capability. – The ability to adjust a weighing or measuring device or change its sealable 

parameters from or through some other device that is not itself necessary to the operation of the weighing or measuring 

device or is not a permanent part of that device. [2.20, 2.21, 2.24, 3.30, 3.37, 3.39, 3.40, 5.56(a)]

(Added 1993)

retail device. – A measuring device primarily used to measure electrical energy for the purpose of sale to the end user.

[3.40]

S

serving utility. – The utility distribution company that owns the master meter and sells electric energy to the owner 

of a submeter system. [3.40]

starting load. – The minimum load above which the device will indicate energy flow continuously. [3.40]

submeter. – A meter or meter system downstream of the electric master meter. [3.40]

(Amended 2021)

T

test accuracy – in-service. – The device accuracy determined by a test made during the period that the system is in 

service. It may be made on the customer’s premises without removing the system from its mounting or by removing 

the EVSE for testing either on the premises or in a laboratory or shop. [3.40]

test amperes (TA). – The full load current (amperage) specified by the EVSE manufacturer for testing and calibration 

adjustment. (Example: TA 30). [3.40]

thermal overload protector. – A circuit breaker or fuse that automatically limits the maximum current in a circuit.

[3.40]
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U

unit price. – The price at which the electrical energy is being sold and expressed in whole units of measurement.

[1.10, 3.30, 3.40]

(Added 1992)

V

vehicle connector. – A device that by insertion into a vehicle inlet, establishes an electrical connection to the electric 

vehicle for the purpose of providing power and information exchange, with means for attachment of an electric vehicle 

cable. This device is a part of the vehicle coupler. [3.40]

vehicle coupler. – A means enabling the connection, at will, of an electric vehicle cable to the equipment. It consists 

of a vehicle connector and a vehicle inlet. [3.40]

vehicle inlet. – The part incorporated in, or fixed to the vehicle, which receives power from a vehicle connector. [3.40]

volt. – The practical unit of electromotive force. One volt will cause one ampere to flow when impressed across a 

resistance of one ohm. [3.40]

W

watt. – The practical unit of electric power. In an alternating-current (AC) circuit, the power in watts is volts times 

amperes multiplied by the circuit power factor. [3.40]

watthour (Wh). – The practical unit of electric energy that is expended in one hour when the average power consumed

during the hour is one watt. [3.40]