DEPARTMENT OF LICENSING AND REGULATORY AFFAIRS  
PUBLIC SERVICE COMMISSION  
TECHNICAL STANDARDS FOR ELECTRIC SERVICE  
(By authority conferred on the public service commission by section 7 of 1909 PA  
106, MCL 460.557, section 2 of 1909 PA 300, MCL 462.2, section 5 of 1919 PA 419,  
MCL 460.55, sections 4 and 6 of 1939 PA 3, MCL 460.4 and 460.6, and sections 3, 9,  
and 231 of the executive organization act of 1965, 1965 PA 380, MCL 16.103, 16.109,  
16.331, and Executive Reorganization Order Nos. 1996-2, 2003-1, 2008-4, and 2011-4,  
MCL 445.2001, 445.2011, 445.2025, and 445.2030)  
PART 1. GENERAL PROVISIONS  
R 460.3101 Applicability; purpose; modification; adoption of rules and  
regulations by utility.  
Rule 101. (1) These rules apply to utility service that is provided by electric utilities  
that are subject to the jurisdiction of the public service commission.  
(2) These rules are intended to promote safe and adequate service to the public and  
to provide standards for uniform and reasonable practices by utilities.  
(3) These rules do not relieve a utility from any of its duties under the laws of the  
state of Michigan. (See R 460.1601(3).)  
(4) Each utility may adopt reasonable rules and regulations governing its relations  
with customers which it finds necessary and which are not inconsistent with these rules  
for electric service. Adopted rules and regulations must be filed with, and approved by,  
the commission.  
(5) An electric utility may petition the commission for a permanent or temporary  
waiver or exception from these rules for good cause shown provided that the waiver or  
exception is consistent with the purpose of these rules.  
History: 1983 AACS; 1996 AACS; 2019 AACS.  
R 460.3102 Definitions.  
Rule 102. As used in these rules:  
(a) Approved by the commission” means that a commission order has been issued.  
(b) “Commission” means the Michigan public service commission.  
(c) “Customer” means an account holder who purchases electric service from a  
utility. An individual who is a customer must be at least 18 years of age or an  
emancipated minor.  
Page 1  
(d) “Electric plant” means all real estate, fixtures, or property that is owned,  
controlled, operated, or managed in connection with, or to facilitate the production,  
transmission, and delivery of, electric energy.  
(e) “Electricity meter” means a device that measures and registers the integral of an  
electrical quantity with respect to time.  
(f) “Electro-mechanical meter” means a meter in which currents in fixed coils react  
with the currents induced in the conducting moving element, generally a disk or disks,  
which causes their movement proportional to the energy to be measured. This meter may  
also be called an induction watthour meter.  
(g) “File” means to deliver to the commission’s executive secretary.  
(h) “Meter” or “watthour meter” means an electricity meter that measures and  
registers the integral with respect to time of the active power of the circuit in which it is  
connected. The unit by which this integral is measured is usually the kilowatt-hour.  
(i) “Meter error” means a failure to accurately measure and record all of the electrical  
quantities used that are required by the applicable rate or rates.  
(j) “Meter shop” means a shop where meters are inspected, repaired, and tested. A  
meter shop may be at a fixed location or may be mobile.  
(k) “Premises” means an undivided piece of land that is not separated by public roads,  
streets, or alleys.  
(l) “Solid state meter” means a meter in which current and voltage act on electronic  
(solid state) elements to produce an output proportional to the energy to be measured.  
(m) “Submit” means to deliver to the commission’s designated representative.  
(n) “Utility” means a firm, corporation, cooperative, association, or other legal entity  
that is subject to the jurisdiction of the commission and that distributes, sells, or provides  
electric service.  
History: 1983 AACS; 1996 AACS; 2019 AACS.  
R 460.3103 Rescission.  
Rule 103. R 460.501 to R 460.505 of the Michigan Administrative Code,  
appearing on pages 4695 to 4709 of the 1979 Michigan Administrative Code, are  
rescinded.  
History: 1983 AACS.  
PART 2. RECORDS AND REPORTS  
R 460.3201 Records; location; examination.  
Rule 201. Upon a request by the commission or  
its  
designated  
representative, records which are required by these rules or which are necessary for  
the administration of these rules shall be available within the state of Michigan for  
examination by the commission or its designated representative.  
Page 2  
History: 1983 AACS; 1996 AACS.  
R 460.3202 Records; preservation.  
Rule 202. Unless otherwise specified in these rules, or by other order of the  
commission, all records that are required by these rules shall be preserved for the  
period of time specified in R 460.2501 et seq. of the Michigan Administrative Code.  
History: 1983 AACS.  
R 460.3203 Documents and information; required submission.  
Rule 203. A utility shall submit all of the following documents and information  
and shall maintain the documents and information in a current status:  
(a) A copy of the utility's tariff.  
(b) A copy of the utility's rules and standards that are made available to the public  
covering meter and service installation.  
(c) A copy of each type of customer bill form.  
(d) A list of the cities, villages, and townships that the utility serves. Upon a  
request by the commission or its designated representative, the utility shall also  
provide copies of the associated franchise information.  
(e) The name, title, address, and telephone number of the persons to be contacted  
in connection with the following matters:  
(i) General management duties.  
(ii) Customer relations (complaints).  
(iii) Engineering operations.  
(iv) Meter tests and repairs.  
(v) Emergencies during non-office hours.  
(f) An annual copy of the utility's construction budget, which shall be updated for  
all major changes to generating and transmission facilities.  
(g) An "Electric Service" monthly report, on forms suitable to the commission,  
that shows information concerning the utility's acquisition and disposition of electric  
energy and other information as required. The reports shall be submitted by investor-  
owned utilities within 50 days after the end of the quarter reported and by rural  
electric cooperatives within 50 days after the end of the month reported.  
(h) A map or maps that show the utility's operating area within this state,  
including generating stations and transmission lines with their voltage designations.  
Upon a request by the commission or its designated representative, the utility shall  
also make available a map or maps that show all of the following:  
(i) Distribution lines with the number of phases designated.  
(ii) State boundary crossings.  
(iii) Service areas.  
History: 1983 AACS; 1996 AACS.  
Page 3  
R 460.3204 Customer records; retention period; content.  
Rule 204. (1) The utility shall retain, either within the utility or as contracted  
through a third party with access by the utility, customer records as necessary to comply  
with R 460.3309. The utility shall retain the records for not less than 3 years.  
(2) Records for customers must show, if applicable, all of the following information:  
(a) Kilowatt-hour meter reading.  
(b) Metered kilowatt-hour consumption.  
(c) Kilowatt, kilovolt ampere, and kilovar meter reading.  
(d) Kilowatt, kilovolt ampere, and kilovar measured demand.  
(e) Kilowatt, kilovolt ampere, and kilovar billing demand.  
(f) Total amount of bill.  
History: 1983 AACS; 1996 AACS; 2008 AACS; 2019 AACS.  
R 460.3205 Security reporting.  
Rule 205. (1) To inform the commission regarding matters that may affect the  
security or safety of persons or property, whether public or private, an electric provider  
must do both of the following:  
(a) Provide a written or oral annual report, individually or jointly with other electric  
providers, to designated members of the commission staff regarding the electric  
provider’s cybersecurity program and related risk planning. This report on the threat  
assessment and preparedness strategy must contain all of the following information:  
(i) An overview of the program describing the electric provider’s approach to  
cybersecurity awareness and protection.  
(ii) A description of cybersecurity awareness training efforts for the electric  
provider’s staff members, specialized cybersecurity training for cybersecurity personnel,  
and participation by the electric provider’s cybersecurity staff in emergency preparedness  
exercises in the previous calendar year.  
(iii) An organizational diagram of the electric provider’s cybersecurity organization,  
including positions and contact information for primary and secondary cybersecurity  
emergency contacts.  
(iv) A description of the electric provider’s communications plan regarding  
unauthorized actions that result in loss of service, financial harm, or breach of sensitive  
business or customer data, including the electric provider’s plan for notifying the  
commission and customers.  
(v) A redacted summary of any unauthorized actions that resulted in material loss of  
service, financial harm, or breach of sensitive business or customer data, including the  
parties that were notified of the unauthorized action and any remedial actions undertaken.  
(vi) A description of the risk assessment tools and methods used to evaluate,  
prioritize, and improve cybersecurity capabilities.  
(vii) General information about current emergency response plans regarding  
cybersecurity incidents, domestic preparedness strategies, threat assessments, and  
vulnerability assessments.  
(b) In addition to the information required under subdivision (a) of this subrule, an  
investor-owned public utility must include in its annual report to the Michigan public  
Page 4  
service commission an overview of major investments in cybersecurity during the  
previous calendar year and plans and rationale for major investments in cybersecurity  
anticipated for the next calendar year.  
(2) As soon as reasonably practicable and prior to any public notification, an electric  
provider must orally report the confirmation of a cybersecurity incident to a designated  
member of the commission staff and to the Michigan fusion center, unless prohibited by  
law or court order or instructed otherwise by official law enforcement personnel, if any of  
the following occurred:  
(a) A person intentionally interrupted the production, transmission, or distribution of  
electricity.  
(b) A person extorted money or other thing of value from the electric provider  
through a cybersecurity attack.  
(c) A person caused a denial of service in excess of 12 hours.  
(d) An unauthorized person accessed or acquired data that compromises the security  
or confidentiality of personal information maintained by the electric provider, as defined  
by section 3(r) of the identity theft protection act, 2004 PA 452, MCL 445.63(r), prior to  
public and customer notification.  
(e) At the electric provider’s discretion, any other cybersecurity incident, attack, or  
threat which the electric provider deems notable, unusual, or significant.  
(3) For purposes of this rule, “electric provider” means any of the following:  
(a) Any person or entity that is regulated by the commission for the purpose of  
selling electricity to retail customers in this state.  
(b) A member-regulated cooperative electric utility in this state.  
(4) For purposes of subrule (2) of this rule, “person” means any individual, firm,  
corporation, educational institution, financial institution, governmental entity, or legal or  
other entity.  
(5) For purposes of subrule (2)(c) of this rule, “denial of service” means, for an  
electric provider, a successful attempt to prevent a legitimate user from accessing  
electronic information made accessible by the electric provider or by another party on the  
behalf of the electric provider.  
History: 2019 AACS.  
PART 3. METER REQUIREMENTS  
R 460.3301 Metered measurement of electricity required; exceptions.  
Rule 301. (1) All electricity that is sold by a utility shall be on the basis of meter  
measurement, except where the consumption can be readily computed or except as  
provided for in a utility's filed rates.  
(2) Where practicable, the consumption of electricity within the utility or by  
administrative units associated with the utility shall be metered.  
(3) Meters shall be in compliance with part 6 of these rules.  
History: 1983 AACS; 1996 AACS.  
Page 5  
R 460.3302 Rescinded.  
History: 1983 AACS; 1996 AACS.  
R 460.3303 Meter reading data.  
Rule 303. The meter reading data must include all of the following information:  
(a) A suitable designation identifying the customer.  
(b) Identifying number and description of the meter.  
(c) Meter readings or, if a reading was not taken, an indication that a reading was not  
taken.  
(d) Any applicable multiplier or constant.  
History: 1983 AACS; 1996 AACS; 2019 AACS.  
R 460.3304 Meter data collection system.  
Rule 304. A meter data collection system that takes data from recording meters must  
indicate all of the following meter information:  
(a) The date of the record.  
(b) The equipment numbers.  
(c) A suitable designation identifying the customer.  
(d) The appropriate multipliers.  
History: 1983 AACS; 1996 AACS; 2019 AACS.  
R 460.3305 Meter multiplier.  
Rule 305. If it is necessary to apply a multiplier to the meter registration,  
then the multiplier shall be displayed on the face of the meter.  
History: 1983 AACS; 1996 AACS.  
R 460.3306 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
R 460.3307 Rescinded.  
History: 1983 AACS; 1996 AACS.  
Page 6  
R 460.3308 Standards of good practice; adoption by reference.  
Rule 308. In the absence of specific rules of the commission, a utility shall apply the  
provisions of the publications set forth in this rule as standards of accepted good practice.  
The following standards are available from the American National Standards Institute  
(ANSI), Customer Service, 25 West 43rd St., 4th floor, New York, New York, 10036,  
USA, telephone number: 1-212-642-4900 or via the internet at website:  
http://webstore.ansi.org at the cost listed below as of the time of adoption of these rules,  
plus a handling charge (for paper copies):  
(a) American National Standards Institute standards for electricity meters ANSI  
C12.1-2014, cost $279.00, and C12.20-2015, cost $107.00.  
(b) American National Standards Institute/American Society for Quality Sampling  
Procedures and Tables for Inspection by Variables for Percent Nonconforming  
(ANSI/ASQ Z1.9-2003(R2013)). Cost $179.00.  
(c) American National Standards Institute IEEE Standard Requirements for  
Instrument Transformers (ANSI C57.13-2016). Cost $119.00.  
(d) American National Standards Institute IEEE Standard for High Accuracy  
Instrument Transformers, IEEE Std. C57.13.6-2005. Cost $57.00.  
History: 1996 AACS; 2008 AACS; 2019 MR 1, Eff. Jan. 9, 2019; 2019 MR 13, Eff. July 16, 2019.  
R 460.3309 Metering inaccuracies; billing adjustments.  
Rule 309. (1) An adjustment of bills for service for the period of inaccuracy must be  
made for over registration and may be made for under registration under any of the  
following conditions:  
(a) A mechanical meter creeps.  
(b) A metering installation is found upon any test to have an average inaccuracy of  
more than 2.0%.  
(c) A demand metering installation is found upon any test to have an average  
inaccuracy of more than 1.0% in addition to the inaccuracies allowed under R 460.3609.  
(d) A meter registration has been found to be inaccurate due to apparent tampering  
by a person or persons known or unknown.  
(2) The amount of the adjustment of the bills for service must be calculated on the  
basis that the metering equipment is 100% accurate with respect to the testing equipment  
used to make the test. The average accuracy of watt-hour meters must be calculated in  
accordance with R 460.3616.  
(3) If the date when the inaccuracy in registration began can be determined, then that  
date must be the starting point for determining the amount of the adjustment and is  
subject to R 460.115.  
(4) If the date when the inaccuracy in registration cannot be determined, then it is  
assumed that the inaccuracy existed for the period of time immediately preceding  
discovery of the inaccuracy that is equal to 1/2 of the time since the meter was installed  
on the present premises, 1/2 of the time since the last test, or 6 years, whichever is the  
shortest period of time, except as otherwise provided in subrule (5) of this rule and  
subject to subrule (12) of this rule.  
(5) The inaccuracy in registration due to creep must be calculated by timing the rate  
of the creeping under R 460.3607 and by assuming that the creeping affected the  
Page 7  
registration of the meter for the period of time immediately preceding discovery of the  
inaccuracy that is equal to 1/4 of the time since the meter was installed on the present  
premises, 1/4 of the time since the last test, or 6 years, whichever is the shortest period of  
time, subject to subrule (12) of this rule.  
(6) If the average inaccuracy cannot be determined by test because part, or all, of the  
metering equipment is inoperative, then the utility may use the registration of check  
metering installations, if any, or estimate the quantity of energy consumed based on  
available data. The utility shall advise the customer of the metering equipment failure  
and of the basis for the estimate of the quantity billed. The same periods of inaccuracy  
must be used as explained in this rule.  
(7) Recalculation of bills must be on the basis of the recalculated monthly  
consumption.  
(8) Refunds must be made to the 2 most recent customers who received service  
through the meter found to be inaccurate. If a former customer of the utility, a notice of  
the amount of the refund must be mailed to such customer at the last known address. The  
utility shall, upon demand made by the customer within 3 months of mailing of the  
notice, forward the refund to the customer.  
(9) If the external meter display is not operating so that the customer can determine  
the energy used, but the meter is recording energy correctly, then no adjustment is  
required. The utility shall repair or replace the meter promptly upon discovery of the  
failure.  
History: 1983 AACS; 1996 AACS; 2008 AACS; 2019 AACS.  
PART 4. CUSTOMER RELATIONS  
R 460.3401 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
R 460.3402 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
R 460.3403 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
Page 8  
R 460.3404 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
R 460.3405 Rescinded.  
History: 1983 AACS; 1996 AACS.  
R 460.3406 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
R 460.3407 Rescinded.  
History: 1983 AACS; 1996 AACS; 2008 AACS.  
R 460.3408 Temporary service; cost of installing and removing equipment  
owned by utility.  
Rule 408. If the utility renders temporary service to a customer, it shall require  
that the customer bear the cost of installing and removing the utility-owned equipment  
in excess of any salvage realized.  
History: 1983 AACS; 1996 AACS.  
R 460.3409 Protection of utility-owned equipment on customer’s premises.  
Rule 409. (1) The customer shall use reasonable diligence to protect utility-owned  
equipment on the customer’s premises and to prevent tampering or interference with the  
equipment. The utility may shut off service in accordance with applicable rules of the  
commission if the metering or wiring on the customer’s premises is unsafe, or has been  
tampered with or altered in any manner that allows unmetered or improperly metered  
energy to be used.  
(2) If a utility shuts off service for unauthorized use of service, then both of the  
following provisions apply:  
(a) The utility may bill the customer for the unmetered energy used and any  
damages that have been caused to utility-owned equipment.  
(b) The utility is not required to restore service until the customer does all of the  
following:  
(i) Makes reasonable arrangements for payment of the charges in subdivision (a) of  
this subrule.  
(ii) Agrees to pay the approved reconnection charges.  
Page 9  
(iii) Agrees to make provisions and pay charges for relocating utility-owned  
equipment or making other reasonable changes that may be requested by the utility to  
provide better protection for its equipment.  
(iv) Provides the utility with reasonable assurance of the customer’s compliance  
with the utility’s approved standard rules and regulations.  
(3) Failure to comply with the terms of an agreement to restore service after service  
has been shut off pursuant to subrule (1) of this rule is cause to shut off service in  
accordance with the rules of the utility and the commission.  
(4) If service is shut off pursuant to subrule (3) of this rule and the utility must incur  
extraordinary expenses to prevent the unauthorized restoration of service, the utility may  
bill the customer for the expenses, in addition to all other charges that may apply under  
this rule, and may require that the expenses and other charges be paid before restoring  
service. A reasonable effort must be made to notify the customer at the time of shutoff  
that additional charges may apply if an attempt is made to restore service that has been  
shut off.  
(5) The customer of record who benefits from the unauthorized use is responsible  
for payment to the utility for the energy consumed.  
(6) The utility may bill the customer for the reasonable actual cost of the tampering  
investigation.  
History: 1983 AACS; 1996 AACS; 2019 AACS.  
R 460.3410 Extension of facilities plan.  
Rule 410. Each utility shall develop a plan, approved by the commission, for the  
extensions of facilities where the investment is in excess of that included in the regular  
rates for service and for which the customer is required to pay all or part of the cost.  
History: 1983 AACS; 1996 AACS.  
R 460.3411 Extension of electric service in areas served by 2 or more utilities.  
Rule 411. (1) As used in this rule:  
(a) "Customer" means the buildings and facilities served rather than the individual,  
association, partnership, or corporation served.  
(b) "Distances" means measurements which are determined by direct  
measurement from the closest point of a utility's existing distribution facilities to the  
customer's meter location and which are not determined by the circuit feet involved in  
any extension.  
(c) "Distribution facilities" means single-phase, V-phase, and 3-phase facilities  
and does not include service drops.  
(2) Existing customers shall not transfer from one utility to another.  
(3) Prospective customers for single-phase service that are located within 300  
feet of the distribution facilities of 2 or more utilities shall have the service of their  
choice.  
Page 10  
(4) Prospective customers for single-phase service that are located more than 300  
feet, but within 2,640 feet, from the distribution facilities of 1 or more utilities shall be  
served by the closest utility.  
(5) Prospective customers for single-phase service that are located more than  
2,640 feet from the distribution facilities of any utility shall have the service of their  
choice, subject to the provisions of subrule (10) of this rule.  
(6) Prospective customers for 3-phase service that are located within 300 feet of  
the 3-phase distribution facilities of 2 or more utilities shall have the service of their  
choice.  
(7) Prospective customers for 3-phase service that are located more than 300 feet,  
but within 2,640 feet, from the 3-phase distribution facilities of 1 or more utilities shall  
be served by the closest utility.  
(8) Prospective customers for 3-phase service that are located more than 2,640 feet  
from the 3-phase distribution facilities of any utility shall have the service of their  
choice, subject to the provisions of subrule (10) of this rule.  
(9) Regardless of any other provisions in these rules, a prospective industrial  
customer, as defined under the industrial classification manual, division D,  
manufacturing, for 3-phase service that will have a connected load of more than 500  
kilowatts shall have its choice of service from any nearby utility that is willing to  
construct the necessary facilities. The facilities that are constructed to serve an  
industrial customer that would otherwise have been served by another utility shall not  
qualify as a measuring point in determining which utility will serve new customers in  
the future.  
(10) The extension of distribution facilities, except as provided in subrules (3),  
(4), (6), and (7) of this rule, where an extension will be located within 1 mile of  
another utility's distribution facilities, shall  
not be made by a utility without first giving the commission and any affected  
utility 10 days' notice of its intention by submitting a map showing the location of  
the proposed new distribution facilities, the location of the prospective customers,  
and the location of the facilities of any other utility in the area. If no objections to  
the proposed extension of distribution facilities are received by the commission within  
the 10-day notice period, the utility may proceed to construct the facilities. If  
objections are received, the determination of which utility will extend service may be  
made the subject of a public hearing and a determination by the commission, upon  
proper application by any affected party.  
(11) The first utility serving a customer pursuant to these rules is entitled to  
serve the entire electric load on the premises of that customer even if another  
utility is closer to a portion of the customer's load.  
(12) A utility may waive its rights to serve a customer or group of customers if  
another utility is willing and able to provide  
commission is notified and has no objections.  
the  
required service and if the  
(13) Nothing contained in these rules shall be construed to circumvent the  
requirements of Act No. 69 of the Public Acts of 1929, as amended, being S460.501  
et seq. of the Michigan Compiled Laws, or to authorize a utility to extend its service  
into a municipality then being served by another utility without complying with the  
provisions of Act No. 69 of the Public Acts of 1929, as amended.  
Page 11  
(14) Regardless of other provisions of this rule, except subrule (9), a utility shall  
not extend service to a new customer in a manner that will duplicate the existing  
electric distribution facilities of another utility, except where both utilities are  
within 300 feet of the prospective customer. Three-phase service does not duplicate  
single-phase service when extended to serve a 3-phase customer.  
(15) The first utility to serve a customer in a new subdivision under the other  
provisions of this rule has the right to serve the entire subdivision. In extending  
service to reach the subdivision, the utility shall not duplicate the existing facilities of  
another utility.  
History: 1983 AACS; 1996 AACS.  
PART 5. ENGINEERING  
R 460.3501  
Electric plant; construction, installation, maintenance, and  
operation pursuant to good engineering practice required.  
Rule 501. The electric plant of the utility shall be constructed, installed,  
maintained, and operated pursuant to accepted good engineering practice in the  
electric industry to assure, as far as reasonably possible, continuity of service,  
uniformity in the quality of service furnished, and the safety of persons and  
property.  
History: 1983 AACS.  
R 460.3502 Standards of good practice; adoption by reference.  
Rule 502. In the absence of specific rules of the commission, a utility shall apply  
the standards of accepted good practice that are adopted by reference in R 460.811 et  
seq.  
History: 1983 AACS; 1988 AACS; 1996 AACS.  
R 460.3503 Utility plant capacity.  
Rule 503. The electric capacity regularly available from all sources shall be  
large enough to meet all normal demands for service and to provide a reasonable  
reserve for emergencies.  
History: 1983 AACS; 1996 AACS.  
R 460.3504 Electric plant inspection program.  
Rule 504. Each utility shall adopt a program of inspection of its electric plant  
to ensure safe and reliable operation. The frequency of the various inspections shall be  
Page 12  
based on the utility's experience and accepted good practice. Each utility shall keep  
sufficient records to verify compliance with its inspection program.  
History: 1983 AACS; 1996 AACS.  
R 460.3505 Utility line clearance program.  
Rule 505. Each utility shall adopt a program of maintaining adequate line clearance  
through the use of industry-recognized guidelines. A line clearance program shall  
recognize the national electric safety code standards that are adopted by reference in R  
460.811 et seq. The program shall include tree trimming.  
History: 1996 AACS.  
PART 6. METERING EQUIPMENT INSPECTIONS AND TESTS  
R 460.3601 Customer-requested meter tests.  
Rule 601. (1) Upon request by a customer to a utility, a utility shall make a test of  
the meter serving the customer. Any charge to the customer shall conform with the  
utility's filed and approved rates and rules. Provided, however, that the utility need  
not make more than 1 test in any 12-month period.  
(2) The customer, or his or her representative, may be present when his or her meter  
is tested.  
(3) A report of the results of the test shall be made to the customer within a  
reasonable time after the completion of the test, and a record of the report, together with  
a complete record of each test, shall be kept on file at the office of the utility.  
History: 1983 AACS.  
R 460.3602 Meter and associated device inspections and tests; certification of  
accuracy.  
Rule 602. Every meter shall be inspected and tested, and associated device(s)  
shall be inspected, in the meter shop of the utility, or a meter testing facility certified by  
the utility, before being placed in service. The accuracy of each meter shall be certified  
to be within the tolerances permitted by these rules, except that the utility may  
rely on the certification of accuracy by the manufacturer on all new meters.  
History: 1983 AACS; 2008 AACS.  
R 460.3603 Meters with transformers; post-installation  
exception.  
inspection;  
Page 13  
Rule 603. Meters with associated instrument transformers and phase shifting  
transformers shall be inspected to determine the proper operation and wiring  
connections. Inspections shall be made within 60 days after installation by a qualified  
person who, when possible, should be someone other than the original installer. All  
self-contained, socket-type meters are excluded from post-installation inspections,  
except that the original installation shall be inspected when the meter is installed.  
History: 1983 AACS.  
R 460.3604 Meters and associated devices; removal tests.  
Rule 604. All meters and associated devices shall be tested after they are  
removed from service unless they are retired because of obsolescence.  
History: 1983 AACS; 1995 AACS.  
R 460.3605 Metering electrical quantities.  
Rule 605. (1) All electrical quantities that are to be metered as provided in R  
460.3301 must be metered by commercially acceptable instruments which are owned and  
maintained by the utility.  
(2) Every reasonable effort must be made to measure at 1 point all the electrical  
quantities necessary for billing a customer under a given rate.  
(3) Metering facilities located at any point where energy may flow in either direction  
and where the quantities measured are used for billing purposes shall consist of meters  
equipped with ratchets or other devices to prevent reverse registration and shall be so  
connected as to separately meter the energy flow in each direction, unless used to  
implement a utility tariff approved by the commission for service provided under a net  
metering program.  
(4) A utility shall not employ reactive metering for determining the average power  
factor for billing purposes where energy may flow in either direction or where the  
customer may generate an appreciable amount of his or her energy requirements at any  
time, unless suitable directional relays and ratchets are installed to obtain correct  
registration under all conditions of operation.  
(5) All electric service of the same type rendered by a utility under the same rate  
schedule must be metered with instruments having like characteristics, except that the  
commission may be requested to approve the use of instruments of different types if their  
use does not result in unreasonable discrimination. Either all of the reactive meters  
which may run backwards or none of the reactive meters used for measuring reactive  
power under 1 schedule must be ratcheted. This rule is only applicable to equipment  
owned by the utility.  
History: 1983 AACS; 2008 AACS; 2019 AACS.  
Page 14  
R 460.3606 Nondirect reading meters and meters operating from instrument  
transformers; marking of multiplier on instruments; marking of charts and  
magnetic tapes; marking of register ratio on meter registers; watthour constants.  
Rule 606. (1) Meters that are not direct reading and meters operating from  
instrument transformers must have the multiplier plainly marked on the dial of the  
instrument or otherwise suitably marked. All charts and magnetic tapes taken from  
recording meters must be marked with the date of the record, the meter number,  
customer, and chart multiplier, except as in R 460.3304.  
(2) The register ratio must be marked on all meter registers.  
(3) The watthour constant for the meter itself must be shown on all watthour meters.  
History: 1983 AACS; 2019 AACS.  
R 460.3607 Watt-hour meter requirements.  
Rule 607. (1) Watthour meters that are used for measuring electrical quantities  
supplied shall conform to ANSI specifications and meet all of the following  
requirements:  
(a) Be of proper design for the circuit on which the meters are used; be in good  
mechanical and electrical condition; and have adequate insulation, correct internal  
connections, and correct register.  
(b) Not creep at no load with all load wires disconnected at a rate of one complete  
revolution of the moving element in ten minutes when potential is impressed.  
(c) Be accurate to within plus or minus 1.0%, referred to the portable standard  
watthour meter as a base, at two unity power factor loads: light load (l.l.) and heavy  
load (h.l.).  
Meter Must be Accurate within ± 1.0% to  
Portable Standard  
Meter  
Class  
Light  
Load  
Heav  
Load e  
Inductiv  
Load  
y
Test  
Test  
50%  
Amperes  
Amperes Lagging  
Power  
Factor  
Test  
Amperes  
Self-  
10%  
75-  
75-  
Contained  
Rated Test 100%  
100% Rated  
Test  
Amperes of  
Amperes  
of Meter  
Rated  
Test  
Amperes Meter  
of Meter  
Transfor  
5-10%  
75-  
75-  
mer Rated  
Rated Test 100%  
100% Rated  
Test  
Amperes of  
Amperes  
of Meter  
Rated  
Test  
Page 15  
Amperes Meter  
of Meter  
(d) Be accurate to within plus or minus 2.0%, referred to the portable standard  
watthour meter as a base, at inductive load (i.l.).  
(2) Polyphase meters shall have their elements in balance within 2.0% at rated test  
amperes at unity power factor and at approximately 50% lagging power factor.  
(3) Meters that are used with instrument transformers shall be adjusted so that the  
overall accuracy of the metering installation meets the requirements of this rule.  
(4) Meters and associated devices shall be adjusted as close as practical to zero  
error and within the accuracy limits specified in subrule (1)(c) of this rule.  
History: 1983 AACS; 2008 AACS.  
R 460.3608 Demand meters, registers, and attachments; requirements.  
Rule 608. A meter that records, or is capable of recording electric demand, is subject  
to the requirements of this rule. A demand meter, demand register, or demand  
attachment that is used to measure a customer’s service shall meet all of the following  
requirements:  
(a) Be in good mechanical and electrical condition.  
(b) Have proper constants, indicating scale, contact device, recording tape or chart,  
and resetting device.  
(c) Not register at no load.  
(d) Curve-drawing meters that record quantity-time curves and integrated-demand  
meters must be accurate to within plus or minus 2.0% of full scale throughout their  
working range. Timing elements measuring specific demand intervals must be accurate  
to within plus or minus 2.0%, and the timing element which serves to provide a record of  
the time of day when the demand occurs must be accurate to within plus or minus 4  
minutes in 24 hours.  
History: 1983 AACS; 2019 AACS.  
R 460.3609 Instrument transformers used in conjunction with metering  
equipment; requirements; phase shifting transformers; secondary voltage.  
Rule 609. (1) Instrument transformers used in conjunction with metering  
equipment to measure a customer's service shall meet both of the following  
requirements:  
(a) Be in proper mechanical condition and have satisfactory electrical insulation  
for the service on which used.  
(b) Have characteristics such that the combined inaccuracies of all transformers  
supplying 1 or more meters in a given installation will not exceed the percentages  
listed in the following chart:  
100% Power  
Factor  
50%  
Power Factor  
Page 16  
Current  
Error 1%  
10%  
0.75% 3%  
100% 10%  
2%  
100%  
(2) Meters that are used in conjunction with instrument transformers shall be  
adjusted so that the overall accuracies will come within the limits specified in this  
part.  
(3) Instrument transformers shall be tested with the meter with which they are  
associated by making an overall test or may be checked separately. If the transformers are  
tested separately, the meters shall also be checked to see that the overall accuracy of the  
installation is within the prescribed accuracy requirements. (See R 460.3613 (6).)  
(4) The results of tests of instrument transformers shall be kept on record and  
shall be available for use.  
(5) Phase shifting transformers shall have secondary voltages under balanced  
line voltage conditions within plus or minus 1.0% of the voltage impressed on the  
primary side of the transformer.  
History: 1983 AACS; 2008 AACS.  
R 460.3610 Portable indicating voltmeters; accuracy.  
Rule 610. All portable indicating voltmeters that are used for determining  
the quality of service voltage to customers shall be checked against a suitable  
secondary reference standard at least once every 6 months for analog devices, and once  
every 12 months for digital devices. The accuracy of these voltmeters shall be rated  
so that the error of the indication is not more than plus or minus 1% of full scale. If  
the portable indicating voltmeter is found to be in error by more than the rated accuracy  
at commonly used scale deflections, it shall be adjusted.  
History: 1983 AACS; 2008 AACS.  
R 460.3611  
Meter testing equipment; availability; provision and use of  
primary standards.  
Rule 611. (1) A utility shall maintain sufficient laboratories, meter testing shops,  
secondary standards, instruments, and facilities to determine the accuracy of all types of  
meters and measuring devices used by the utility. The utility may, if necessary, have  
all or part of the required tests made, or its portable testing equipment checked, by  
another utility or agency which is approved by the commission and which has  
adequate and sufficient testing equipment to comply with these rules.  
(2) At a minimum, a utility shall keep all of the following testing equipment  
available:  
(a) One or more portable standard watthour meters that has  
a
capacity and  
voltage range which is adequate to test all watthour meters used by the utility.  
(b) Portable indicating instruments that are necessary to determine the accuracy of  
all instruments used by the utility.  
Page 17  
(c) One or more secondary standards to check each of the various types of portable  
standard watthour meters used for testing watthour meters. Each secondary standard  
shall consist of an approved portable standard watthour meter which is kept  
permanently at 1 point and which is not used for fieldwork. Standards shall be well-  
compensated for both classes of temperature errors, shall be practically free from  
errors due to ordinary voltage variations, and shall be free from erratic registration due  
to any cause.  
(d) Suitable standards, which are not used for fieldwork, to check portable  
instruments used in testing.  
(3) A utility shall provide and use primary standards that have  
accuracies which are traceable to the United States National Institute of  
Standards and Technology (NIST).  
History: 1983 AACS; 1995 AACS.  
R 460.3612 Test standards; accuracy.  
Rule 612. (1) The accuracies of all primary reference standards shall be certified  
as traceable to the National Institute of Standards and Technology (NIST), either directly  
or through other recognized standards laboratories.These standards shall have their  
accuracy certified at the time of purchase.Standard cells shall be intercompared regularly  
and at least 1 standard cell shall be checked by a standardizing laboratory at intervals of  
not more than 2 years. Reference standards of resistance, potentiometers, and volt  
boxes shall be checked at intervals of not more than 3 years.  
(2) Secondary watthour meter standards shall not be in error by more than plus or  
minus 0.3% at loads and voltages at which they are to be used, and shall not be used to  
check or calibrate working standards, unless the secondary standard has been checked  
and adjusted, if necessary, within the  
preceding 6 months. Each secondary standard watthour meter shall have  
calibration data available and shall have a history card.  
(3) Secondary standards indicating instruments shall not be in error by more than  
plus or minus 0.5% of indication at commonly used scale deflection and shall not be  
used to check or calibrate portable indicating instruments, unless the secondary standard  
has been checked and adjusted, if necessary, within the preceding 12 months. A  
calibration record shall be maintained for each standard.  
(4) Regularly used working portable standard watthour meters shall be compared  
with a secondary standard at least once every 6 months. Infrequently used working  
standards shall be compared with a secondary standard before they are used.  
(5) Working portable standard watthour meters shall be adjusted so that their  
percent registration is within 99.7% and 100.3% at 100% power factor and within  
99.5% and 100.5% at 50% lagging power factor at all voltages and loads at which the  
standard may be used. A history and calibration record shall be kept for each working  
standard.  
(6) The meter accuracies required in this rule for all primary, secondary, and  
working standards shall be referred to 100%. Service measuring equipment shall be  
Page 18  
adjusted to within the accuracies required assuming the portable test equipment to be  
100% accurate with the calibration correction taken into consideration.  
History: 1983 AACS; 1995 AACS; 2008 AACS.  
R 460.3613 Meter and metering equipment testing requirements.  
Rule 613. (1) The testing of any unit of metering equipment must consist of a  
comparison of its accuracy with a standard of known accuracy. Units that are not  
properly connected or that do not meet the accuracy or other requirements of these meter  
and metering equipment rules at the time of testing shall be reconnected or rebuilt to meet  
such requirements and must be adjusted to within the required accuracy and as close to  
zero error as practicable or else their use shall be discontinued.  
(2) Self-contained, electro-mechanical, solid state, single-phase, and all network  
meters must be in compliance with all of the following requirements:  
(a) Be checked for accuracy as provided for in R 460.3602.  
(b) Notwithstanding the provisions of subdivision (a) of this subrule, upon  
application to the commission and upon receipt of an order granting approval, the testing  
of self-contained, electro-mechanical, solid state, single-phase, and all network meters in  
service must be governed by a quality control plan as follows:  
(i) Meters must be divided into homogenous groups by manufacturerstypes, and  
certain manufacturers’ types must be further subdivided into separate groups by  
manufacturers’ serial numbers.  
(ii) The meters in each homogeneous group must then be further subdivided into lots  
of not less than 301, and not more than 35,000, meters each, except that meters of the  
most recent design may be combined into lots regardless of manufacturers’ type, except  
that where the number of meters of a single type is 8,001 or more, that number of meters  
must be segregated by types for the formation of lots.  
(iii) From each assembled lot, a sample of the size specified in table A-2,  
ANSI/ASQC Z1.9, must be drawn annually. The sample must be drawn at random.  
(iv) The meters in each sample must be tested for accuracy pursuant to paragraphs  
(v) to (xi) of this subdivision.  
(v) The test criteria for acceptance or rejection of each lot must be based on the test  
at heavy load only and must be that designated for double specification limits and an  
acceptable quality level (AQL) that is not higher than 2.50 (normal inspection) as shown  
in table B-3, ANSI/ASQC Z1.9.  
(vi) The necessary calculations must be made pursuant to Example B-3 of  
ANSI/ASQC Z1.9. The upper and lower specification limits, U and L, must be 102%  
and 98%, respectively.  
(vii) A lot must be rejected if the total estimated percent defective (p) exceeds the  
appropriate maximum allowable percent defective (M) as determined from table B-3 as  
specified in paragraph (v) of this subdivision.  
(viii) All meters in a rejected lot must be tested within a maximum period of 60  
months and be adjusted pursuant to the provisions of R 460.3607 or be replaced with  
meters that are in compliance with the requirements of R 460.3607.  
Page 19  
(ix) During each calendar year, new meter samples must be drawn as specified in  
this subdivision from all meters in service, with the exception that lots that have been  
rejected must be excluded from the sampling procedure until all meters included in the  
rejected lots have been tested.  
(x) The utility may elect to adopt a mixed variables-attributes sampling plan as  
outlined in Section A9 of ANSI/ASQC Z1.9, in which case, a lot that is not in  
compliance with the acceptability criteria of the variables sampling plan shall be  
resampled the following year using an attributes sampling plan. If the acceptability  
criteria of the attributes sampling plan are met, then the lot shall be considered acceptable  
and shall be returned to the variables sampling plan the following year. If the  
acceptability criteria of the attributes sampling plan are not met, then the utility shall  
reject that lot and all meters in the lot must be tested and adjusted or replaced within a  
maximum period of 48 months after the second rejection.  
(xi) The plan specified in paragraph (x) of this subdivision does not alter the rules  
under which customers may request special tests of meters.  
(c) Be checked for accuracy in all of the following situations:  
(i) When a meter is suspected of being inaccurate or damaged.  
(ii) When the accuracy of a meter is questioned by a customer. (See R 460.3601.)  
(d) Be inspected for mechanical and electrical faults when the accuracy of the device  
is checked.  
(e) Have the register and the internal connections checked before the meter is first  
placed in service and when the meter is repaired.  
(f) Have the connections to the customer’s circuits checked when the meter is tested  
on the premises or when removed for testing.  
(g) A meter need not be tested or checked for any reason if the device was tested,  
checked, and adjusted within the previous 12 months except when a complaint is  
received.  
(3) All single-phase instrument rated electro-mechanical meters must be in  
compliance with all of the following requirements:  
(a) Be checked for accuracy at unity power factor at the point where a meter is  
installed, at a central testing point, or in a mobile testing laboratory as follows:  
(i) Not later than 9 months after 144 months of service for a surge-resistant meter  
and not later than 9 months after 96 months of service for a non-surge-resistant meter.  
(ii) When a meter is suspected of being inaccurate or damaged.  
(iii) When the accuracy of a meter is questioned by a customer. (See R 460.3601.)  
(iv) Before use when a meter has been inactive for more than 1 year after having  
been in service.  
(b) Be inspected for mechanical and electrical faults when the accuracy of the device  
is checked.  
(c) Have the register and the internal connections checked before the meter is first  
placed in service and when the meter is repaired.  
(d) Have the connections to the customer’s circuits checked when the meter is tested  
on the premises or when removed for testing.  
(e) Be checked for accuracy at 50% power factor when purchased and after  
rebuilding.  
Page 20  
(f) A meter need not be tested or checked for any reason if the device was tested,  
checked, and adjusted within the previous 12 months except when a complaint is  
received.  
(4) All self-contained electro-mechanical and solid state 3-phase meters and  
associated equipment must be in compliance with all of the following requirements.  
However, a utility may elect to include self-contained solid state 3-phase meters in  
service in its quality control plan as provided for in R 460.3613(2)(b). Therefore, a utility  
may be exempt from the periodic meter test requirements as provided in subdivision  
(a)(ii) of this subrule.  
(a) Be tested for accuracy at unity and 50% power factor as follows:  
(i) Before being placed in service.  
(ii) Not later than 9 months after 120 months of service.  
(iii) When a meter is suspected of being inaccurate or damaged.  
(iv) When the accuracy of a meter is questioned by a customer. (See R 460.3601.)  
(v) When a meter is removed and put back in service.  
(b) Be inspected for mechanical and electrical faults when the accuracy is checked.  
(c) Have the register and internal connections checked before the meter is first  
installed, when repaired and when the register is changed.  
(d) Have the connections to the customer’s circuits and multipliers checked when  
the equipment is tested for accuracy on the customer’s premises.  
(5) All transformer-rated electro-mechanical and solid state 3-phase meters and  
associated equipment must be in compliance with all of the following requirements.  
However, a utility may elect to include transformer-rated solid state 3-phase meters in  
service in its quality control plan as provided for in R 460.3613(2)(b). Therefore, a utility  
may be exempt from the periodic meter test requirements as provided in subdivision  
(a)(iii) of this subrule.  
(a) Be checked for accuracy at unity and 50% power factor as follows:  
(i) Before being placed in service.  
(ii) On the customer’s premises within 60 days after installation, unless the  
transformers are in compliance with the specifications outlined in the American National  
Standards Institute standard ANSI C-57.13, and unless the meter adjustment limits do not  
exceed plus or minus 1.5% at 50% power factor.  
(iii) Not later than 9 months after 72 months of service.  
(iv) When a meter is suspected of being inaccurate or damaged.  
(v) When the accuracy is questioned by a customer. (See R 460.3601.)  
(vi) When a meter is removed and put back in service.  
(b) Be inspected for mechanical and electrical faults when the accuracy is checked.  
(c) Have the register and internal connections checked before the meter is first  
placed in service and when the meter is repaired.  
(d) Have the connections to the customer’s circuits and multipliers checked when  
the equipment is tested for accuracy on the premises or when removed for testing and  
when instrument transformers are changed.  
(e) Be checked for accuracy at 50% power factor when purchased and after  
rebuilding.  
(6) A utility shall test instrument transformers in all of the following situations:  
Page 21