20220427IPC, IDA and Avista Joint Comments.pdf

LISA D. NORDSTROM
Lead Counsel
[e-mail]
April 27, 2022
Ms. Jan Noriyuki
Commission Secretary
Idaho Public Utilities Commission
11331 West Chinden Blvd, Bldg. 8, Ste 201-A
Boise, ID 83714
[e-mail]
RE: Case No. RUL-U-22-01
Rules for the Measurement of Stray Current or Voltage (The Stray Voltage
Rules), DOCKET NO. 31-6101-2201
Dear Ms. Noriyuki:
Idaho Power Company (“Idaho Power” or “Company”), Avista Corporation, and the
Idaho Dairymen’s Association, Inc. (together, the “Commenters”) appreciate the opportunity
to comment on the proposed changes to the Idaho Public Utilities Commission
(“Commission”) IDAPA 31.61.01 - Rules for the Measurement of Stray Current or Voltage
(“Stray Voltage Rules”).
The Commenters have reviewed and are supportive of Commission Staff’s (“Staff”)
draft revisions to the Stray Voltage Rules. The Commenters also identified additional
opportunities to further streamline the Stray Voltage Rules, effectively reducing unnecessary
text, and provided minor clarifications to better align the Stray Voltage Rules with practical
field application.
To support the Commission, Staff, and other parties’ review of the Commenters’
proposed revisions, two attachments accompany this filing. Attachment 1 contains all redlines
(both those proposed by Staff and those proposed by the Commenters) in a single document,
and Attachment 2 isolates only the Commenters’ proposed revisions (in this document, Staff’s
proposed redlines have been “accepted” and only the Commenters’ additional edits are
visible as tracked changes).
Below is a summary of the Commenters’ proposed revisions which are also explained
within the comments in Attachment 2:
RECEIVED
2022 APR 27 PM 4:24
IDAHO PUBLIC
UTILITIES COMMISSION
Idaho Public Utilities Commission
April 27, 2022
Page 2

Section Description of change 
010.01 Modification: corrected misspelling, added specific code references 
010.02 Deleted section – may be omitted without creating confusion 
010.05 Modification: Replaced definition with reference to NEC – the source of this 
definition 
010.09 Deleted unnecessary text to simplify statement 
010.10 Modification: Revised definition to be consistent with industry practice and other 
references. 
010.11 Modification: Revised definition to be consistent with industry practice and other 
references.  
010.12 Deleted section – definition included in IDAPA 61‐802 
010.13 Deleted unnecessary text 
010.13.a. Deleted section – definition included in IDAPA 61‐802 
010.13.b. Deleted section – definition included in IDAPA 61‐802 
010.13.c. Deleted section – definition included in IDAPA 61‐802 
010.14 Deleted unnecessary text 
010.15 Modified to improve clarity and reduce wordiness. 
010.16 Deleted unnecessary text to simplify statement 
022.01 Deleted portion included in IDAPA 61‐804 
023. Deleted portion already included in section 010.09 
024. Deleted section – requirement is included in IDAPA 61‐803 
051.03 Modified for clarity and accuracy 
071.03 Modified to align better with the testing dairy producers sometimes request. 
Eliminated the requirement for a “written” agreement to suspend or limit testing.  
073.03.c.i. Modified to allow the use of different types of brushes 

Finally, the Commenters support Staff’s recommendation to remove the existing
figures from the Stray Voltage Rules and instead house them on the Commission’s website.
In support of this proposal, the enclosed Attachment 3 contains new images to replace the
pixilated and dated figures currently existing within the Stray Voltage Rules. These new
images are available as individual electronic image files.

The Commenters appreciate the opportunity to provide additional recommendations
for the Commission’s consideration.

Idaho Public Utilities Commission
April 27, 2022
Page 3

Respectfully submitted,

___________________
Lisa D. Nordstrom
Idaho Power Company
1221 W. Idaho Street
P.O. Box 70
Boise, Idaho 83707

Attorney for Idaho Power Company

Respectfully submitted,

_____________________________
Rick Naerebout
Idaho Dairymen’s Association, Inc.
195 River Vista Place
Suite 308
Twin Falls, Idaho 83301

Representative for Idaho Dairymen’s
Association, Inc.

Respectfully submitted,

/s/ David Meyer_______
David Meyer
Avista Corporation
P.O. Box 3727
1411 E. Mission Avenue
Spokane, WA 99202

Attorney for Avista Corporation

ATTACHMENT 1

31.61.01 – RULES FOR THE MEASUREMENT OF
STRAY CURRENT OR VOLTAGE
(THE STRAY VOLTAGE RULES)

GENERAL PROVISIONS

Rules 0 through 11

000. LEGAL AUTHORITY (RULE 0).
These rules are promulgated pursuant to the authority of the Idaho Public Utilities Law, Sections 61-515 and 61-520,
Idaho Code, and the Stray Current and Voltage Remediation Act, Section 61-803, Idaho Code. ( )

001. TITLE AND SCOPE (RULE 1).

01. Title. The title of these rules is the IDAPA 31.61.01, “Rules for the Measurement of Stray Current
or Voltage” (Stray Voltage Rules). ( )

02. Scope. These rules are applicable to dairy producers, public utilities and all persons or entities
involved in any way in the measurement or remediation of stray current or voltage within Idaho. ( )

002. WRITTEN INTERPRETATIONS – AGENCY GUIDELINES (RULE 2).
Written interpretations to these rules can be obtained from the Secretary of the Idaho Public Utilities Commission and
are available from the office of the Commission Secretary. ( )

003. ADMINISTRATIVE APPEALS (RULE 3).
There are no provisions for administrative appeals within the Commission under these rules. ( )

004. INCORPORATION BY REFERENCE – REFERENCE TO SAFETY CODES (RULE 4).

01. Safety Codes. These rules reference two (2) national safety codes. ( )

a. The National Electrical Safety Code (NESC) is applicable to public utilities and is adopted by the
Commission Order in IDAPA 31.11.01, “Safety and Accident Reporting Rules for Utilities Regulated by the Idaho
Public Utilities Commission.” ( )

b. The National Electrical Code (NEC) is applicable to the installation of wires and facilities used to
convey electric current and to apparatus to be operated by such electric current. Adoption of the National Electrical
Code is found at Section 54-1001, Idaho Code, and IDAPA 07.01.06, “Rules Governing the Use of National Electrical
Code,” Section 011. ( )

005. -- 009. (RESERVED)

010. DEFINITIONS (RULE 10).

01. These Rules incorporate by references definitions found in Idaho Code 61-802, the NEC, and the NESC.
01. Adequate Remediation. Means corrective action taken by a utility which results in, and is
reasonably likely to sustain, a reduction of stray current or voltage attributable to the utility’s distribution system to a
measured level that is fifty percent (50%) or less of the preventive action level. ( )

02. Ampere. A unit of measure of current. A milliampere is one-one thousandths (1/1,000) of an
ampere. ( )
03. Commission. Means the Idaho Public Utilities Commission. ( )
Commented [OP1]: Explicitly adding the NEC and NESC as
additional sources of definitions.
Commented [SG2]: Certain definitions are in Idaho Code
61-802
Commented [OP3]: Standard terminology – may be
omitted without creating confusion. (NEC doesn’t include it,
and we don’t include “volt.”)

04. Cow Contact Points. Means any two (2) points on electrically conductive materials in a dairy which
a dairy cow may (in its normal environment on the dairy) unavoidably and simultaneously contact. Electrically
conductive material may include the surface(s) that the cow is standing on as one (1) or both cow contact points.
( )

05. Equipotential Plane (EPP). See NEC.Means an area where wire mesh or other conductive elements
are embedded in or placed under concrete, bonded to all metal structures and fixed nonelectrical equipment that may become energized, and connected to the electrical grounding system to prevent a difference in voltage from developing
within the plane. ( )

06. Preventive Action Level (PAL). Stray current or voltage that, when correctly measured, is either:
( )

a. A steady state, root mean square (rms) alternating current (AC) of two (2) milliamperes (mA) or
more through a five hundred (500) ohm resistor (i.e., shunt resistor) connected between cow contact points, as
measured by a true rms meter, or; ( )

b. Any steady state, rms AC voltage of one (1.0) volt or more across (in parallel with) a five hundred
(500) ohm resistor (i.e., shunt resistor) connected between cow contact points, as measured by a true rms meter.
( )

07. Primary System. A term that describes the high High voltage utility electrical system including the
generation, transmission and distribution systems. It also refers to the high voltage side of a distribution transformer.
( )

08. Secondary System. Means Tthe low-voltage utility electrical system on the secondary side of a
distribution transformer. The dairy’s on-farm system begins on the dairy’s side of the metering points, except for
dairies metered on the high voltage side of the transformer(s). In the case of dairies metered on the high voltage side,
the on-farm system begins at the transformer’s low-voltage lugs. ( )

09. Service Provider. Means any Any person, company or other legal entity providing stray voltage or
current testing, consulting, measurements, analysis services, construction, or hardware. ( )

10. Shunt Resistor. A physical resistor or combination of resistors used to simulate a dairy cow’s body
resistance, body-to-metal contact resistance, and hoof-to-earth contact resistance between the cow and contact points
during the measurement of cow contact voltage. As used in these rules, Aa shunt resistor shall be five hundred (500)
ohms plus or minus two percent (+/- 2%). ( )

11. Source Resistance. Means tThat portion of resistance in the circuit, other than the resistance of the
cow and its contact resistance, when the cow is completing a circuit between contact points. Body-to-metal contact
resistance and hoof-to-earth resistance may represent a portion of the source resistance. ( )

12. Steady State. The value of a current or voltage after an amount of time has passed where all
transients have decayed to a negligible value. ( )

13. Stray Current or Voltage. Stray voltage or current is: ( )

a. Any steady state, sixty (60) hertz (Hz) (including harmonics thereof) root mean square (rms)
alternating current (AC) less than twenty (20) milliamperes (mA) through a five hundred (500) ohm resistor (i.e.,
shunt resistor) connected between cow contact points, as measured by a true rms meter; or ( )

b. Any steady state, sixty (60) Hz (including harmonics thereof), rms AC voltage of less than ten (10)
volts, across (in parallel with) a five hundred (500) ohm resistor (i.e., shunt resistor) connected between cow contact
points, as measured by a true rms meter. ( )

Commented [OP4]: Definition was effectively identical to
NEC definition. Replacing definition with citation will keep
the definition of EPP consistent.
Commented [OP5]: Clarification of original definition.
Cows don’t make a nearly zero-ohm connection to their
environment like metal voltage test-leads can. The 500-ohm
shunt resistor is intended as a substitute for both the cow’s
internal body resistance and any contact resistance
between a cow and its environment. (ref. IEEE Std. 1695-
2016 section 5.5.1.4, and USDA 696 pages 5-5, 5-10.
Commented [OP6]: See above – contact resistance is
included in the shunt resistor for measurement purposes.
Commented [OP7]: Defined in IDAPA 61-802.

c. Stray current and voltage is a normal, inherent and unavoidable result of electricity traveling through
grounded electrical systems, including a dairy producer’s on-farm system and a utility’s distribution system. These
systems are required by the National Electrical Code (NEC) and the National Electrical Safety Code (NESC) to be
grounded to the earth to ensure safety and reliability. ( )

d. Unless the context otherwise requires, the term “stray voltage” shall mean stray current or stray
voltage. ( )
14. Tests, Measurements, Procedures and Analysis. Means aAny or all of the stray voltage testing,
measurement, work and work product defined in these rules. ( )

15. Transient or Transient Deviation. Transient or transient deviation means a A non-steady state
increase or spike in voltage or current. For the purpose of identifying and reporting transients in cow contact voltage
(Vcc) or current (Icc), a transient occurs when the recorded maximum Vcc or Icc in a recording interval exceeds two
hundred percent (200%) of the steady state Vcc or Icc recorded during the same recording interval. ( )

16. Utility. Means aA public electric utility as defined in Section 61-332A, Idaho Code. ( )

011. PURPOSE OF RULES -- CONFORMANCE TO ELECTRICAL CODE (RULE 11).
These rules standardize the measurement and testing procedures used to measure stray voltage and current.
Standardization of testing will provide a consistent basis for determining the presence and level of stray voltage in a
dairy and how to determine the source of that stray voltage or current. These rules do not replace existing safety
standards embodied in electrical codes. Any conflict between these rules and the National Electrical Code or the
National Electrical Safety Code shall be promptly brought to the attention of the Commission. Under these rules,
testing is intended to determine: ( )

01. Presence of Stray Voltage. The presence and amount of any stray voltage or current within the
dairy. ( )

02. Sources of Stray Voltage. The source(s) of any stray voltage or current detected. ( )

03. Contributions to Stray Voltage. The percent contribution from the utility side and the dairy side
of the dairy service entrance to the total stray voltage or current measured on the dairy. ( )

012. -- 020. (RESERVED)

APPLICABILITY AND ADMISSIBILITY

Rules 21 through 30

021. UTILITY (RULE 21).
A utility measuring or testing for stray voltage or current at the request of a dairy producer, as directed by the
Commission or on its own initiative, shall conduct such measurements in accordance with these rules. ( )

022. DAIRY PRODUCER (RULE 22).

01. Serving Notice on the Utility. A dairy producer providing written notice to a utility pursuant to
Section 61-804, Idaho Code, shall specify why the dairy producer believes its dairy cows are being affected by
electrical energy attributable to the utility. A dairy producer may provide such notice with or without first having
conducted tests or measurements of stray voltage. ( )

02. Cooperation. When a written notice is filed with the utility, the dairy is obligated to make any
contact point(s), service panels, grounding rods or other electrical equipment at the dairy available to the utility for
measuring and testing. The utility shall provide reasonable notice and cooperate with the dairy producer to establish
an appropriate time to conduct the tests and measurements. The dairy shall cooperate with the utility so that all tests
Commented [OP8]: (a), (b), and (c) are defined and
described in IDAPA 61-802. Note – (d) should be kept.
Commented [SG9]: The purpose of the rules is the
enabling statute in Idaho Code.
Commented [OP10]: The “why” requirement for the
notice is included in IDAPA 61-804.

and measurements necessary to identify the existence and magnitude of stray current or voltage, if any, are completed
within fourteen (14) days of the utility’s receipt of such notice. ( )

023. SERVICE PROVIDERS (RULE 23).
Any person performing any stray voltage measurement or test on behalf of a utility or a dairy shall be deemed a service
provider and All service providers shall follow these rules. ( )

024. ADMISSIBILITY (RULE 24). Only tests and measurements made in compliance with these rules shall be admissible before the Commission or in
any civil action. ( )

025. -- 030. (RESERVED)

QUALIFICATIONS OF PERSONS
PERFORMING AND ANALYZING
RESULTS OF STRAY VOLTAGE TESTS

Rules 31 through 40

031. PERFORMANCE OF TESTS AND MEASUREMENTS (RULE 31).
Measuring and testing for stray voltage under these rules for consideration by the Commission shall be performed by
a qualified testing professional, such as: The following persons are presumed to be qualified testing professionals: (
)

01. Professional Engineer. A professional engineer, licensed in any state, who has completed no fewer
than forty-eight (48) hours of Commission-approved stray voltage training and who has been involved in no fewer
than five (5) prior investigations involving the measurement or testing of stray voltage. ( )

02. Master Electrician. A master electrician, licensed in any state, who has completed no fewer than
forty-eight (48) hours of Commission-approved stray voltage training and who has been involved in no fewer than
five (5) prior investigations involving the measurement or testing of stray voltage. ( )

03. Technician. A technician who, under the supervision of a person presumed qualified under
Subsections 031.01 and 031.02, has completed no fewer than eight (8) hours of Commission-approved stray voltage
training and who has been involved in no fewer than five (5) prior investigations involving the measurement or testing
of stray voltage. ( )

032. DATA ANALYSIS (RULE 32).
Analysis of data under these rules, for consideration by the Commission, shall be performed by a qualified analyst. A
professional engineer, licensed in any state, who has completed no fewer than forty-eight (48) hours of stray voltage
training and who has been involved in no fewer than five (5) prior investigations involving measurement or testing of
stray voltage shall be presumed to be a qualified analyst. ( )

033. PERSONS OTHERWISE QUALIFIED (RULE 33).
A person who does not satisfy the qualifications in Sections 031 and 032, may nonetheless be determined by the
Commission to be a qualified testing professional or a qualified analyst if, on motion of any party, the Commission
finds that person otherwise possesses the knowledge, skill, experience, training, or education that qualifies that person
to offer expert testimony before the Commission. ( )

034. -- 050. (RESERVED)

CALIBRATION OF AND EQUIPMENT USED FOR MEASURING
Commented [OP11]: Service Providers is already defined
in the definitions section. This applicability section didn’t
change that definition.
Commented [OP12]: This requirement is included in
IDAPA 61-803.

AND RECORDING
VOLTAGE, CURRENT, AND RESISTANCE

Rules 51 through 60

051. GENERAL REQUIREMENTS FOR STRAY VOLTAGE MEASURING AND RECORDING
EQUIPMENT (RULE 51).
Equipment used for the measurement or testing of stray voltage, current, and resistance shall meet the following
criteria: ( )

01. Resolution and Accuracy. The accuracy and resolution of any instrument used to measure or record
cow contact voltage or current, shall limit the error to five percent (5%) or less at one volt (1 V) or two milliampere
(2 mA). ( )

02. Voltage Measurement. Instruments used to measure cow contact voltage shall be capable of
separating and independently measuring alternating current (AC) and direct current (DC) voltages. These instruments
shall have a minimum internal impedance of ten thousand (10,000) ohm and shall be capable of measuring the true-
rms voltage. ( )
03. Current Measurement. A clamp-on ammeter, a digital multi-meter (DMM) with clamp-on device,
or an in-line ammeter shall be used to measure current through a conductor or resistor connected between two (2)
points. The meters shall be capable of separating and independently measuring alternating current (AC) and direct
current (DC) and shall be capable of measuring the true-rms current. Care must be taken to assure that clamp-on ammeters used have the required resolution and accuracy. ( )

04. Resistance Measurement. Resistance shall be measured using either a volt ohmmeter (VOM) or a
DMM. Resolution shall be to the level of one (1) ohm or less when measuring a resistance of less than one thousand
(1,000) ohm. Accuracy shall be within plus or minus five (+/-5) ohm for a five hundred (500) ohm resistance.
( )

05. Resistance-to-Earth Measurement. Grounding electrode resistance-to-earth measurements shall
be made with a three- (3) point fall-of-potential instrument or a clamp-on resistance-to-earth tester. ( )

052. CALIBRATION REQUIREMENTS (RULE 52).

01. Measuring Equipment Calibration. All measuring equipment shall be calibrated according to the
manufacturer’s recommended calibration schedule, but no less than annually, to meet the manufacturer’s
specifications for the accuracy and resolution of the equipment. Measuring equipment shall not be used after its next
“calibration due” date for measurements or tests conducted during a stray voltage investigation. Calibration shall be
performed by either: ( )

a. The manufacturer of the equipment, who shall certify that the equipment meets the manufacturer’s
specifications for accuracy and resolution; or ( )

b. A laboratory currently certified as meeting all applicable Institute of Electrical and Electronic
Engineers (IEEE) and International Organization for Standards (ISO) standards. ( )

02. Calibration Certificates. The service provider performing the tests and measurements shall
maintain certificates from the manufacturer or the calibration laboratory demonstrating compliance with calibration
requirements. ( )

03. Field Check. Before voltage or current measurement or testing is performed, the instrument shall
be field-checked by comparing measurements to those of other instruments or against a known source. ( )

Commented [OP13]: Clarification for accuracy. There
may be multiple current paths between two points. A clamp-on ammeter only measures the current in the
conductor(s) it is clamped around.

053. REQUIREMENTS FOR MONITORING AND RECORDING DEVICES (RULE 53).
Digital recording devices shall be used for the purpose of recording current and voltage for extended periods, such as
the forty-eight (48) hour test. The recording devices shall have the same level of resolution and accuracy as the meters
being used for the measurements. Monitoring systems, which combine measuring and recording functions in a single
instrument, shall have the same level of resolution and accuracy as specified in Section 051. Recording devices and
monitoring systems shall be capable of recording transient deviations of one-tenth (0.1) second or less in duration
from the steady state. Digital recording devices, which have deviation settings, shall permit the deviation setting to be
set “low” enough to meet the resolution and accuracy requirements in Subsection 051.01 of these rules. All recording devices shall be able to log the time and date of all data recorded and shall have their internal clocks synchronized.
( )

054. REQUIREMENTS FOR LOAD BOXES (RULE 54).
The load box shall meet the following criteria: ( )

01. Volts. A load box shall be a primarily non-inductive nominal two hundred forty (240) volt,
resistance heating type load with a minimum nominal full load of eighteen (18) kilowatts (kW). ( )

02. Split-Load. A load box shall be capable of operating at two (2) or more load settings, including
approximately fifty percent (50%) and one hundred percent (100%) of the load box’s rated total load. ( )

055. -- 070. (RESERVED)

TESTING AND MEASUREMENT PROCEDURES
Rules 71 through 80

071. STRAY CURRENT OR VOLTAGE TESTS (RULE 71).
Subject to Subsection 071.02, there are six (6) tests used to detect and measure stray current or voltage. ( )

01. Scheduling of Stray Voltage Tests. Efforts shall be made to perform the tests under conditions
substantially similar to those conditions existing at the time(s) the dairy producer believes stray voltage to be a
problem. ( )

a. Test 1 - Cow Contact Test; ( )

b. Test 2 - Forty-Eight (48) Hour Test; ( )

c. Test 3 - Primary Profile Test; ( )
d. Test 4 - Secondary Neutral Voltage Drop Test; ( )

e. Test 5 - Load Box Test; and ( )
f. Test 6 - Signature Test. ( )

02. Testing Sequence. Test 1 shall be performed first. Tests 1 and 2 are used to determine the presence
and level of stray voltage and shall be performed in all investigations, subject to the provisions of Subsection 071.03.
Tests 3, 4, 5, and 6 may be performed in any order and may be performed without first determining that these tests are
required under Paragraph 071.02.b. Tests 3, 4, 5, and 6 may be performed prior to starting the recording for Test 2 or
while Test 2 is in progress. Test 2 may be interrupted as necessary to conduct Tests 4, 5, and 6, or for review and
analysis of the data recorded up to that point. ( )

a. If the results from Tests 1 and 2 indicate that stray voltage does not exceed the preventive action
level (PAL), the utility has no further testing or remediation obligations under these rules during this test cycle.
( )

b. If the PAL is exceeded, the utility shall perform the remaining four (4) tests except as provided in
Subsection 071.03. The utility shall also perform analysis to determine whether the portion of the stray current or
voltage attributable to an off-farm source exceeds fifty percent (50%) of the PAL. ( )

c. If the PAL is exceeded, and the portion of the stray current or voltage attributable to an off-farm
source does not exceed fifty percent (50%) of the PAL, the utility has no further testing or remediation obligations.
( )
d. If the PAL is exceeded, and the portion of the stray current or voltage attributable to an off-farm
source exceeds fifty percent (50%) of the PAL, the utility shall conduct remediation pursuant to Section 091. Under
this condition, the forty-eight (48) hour recording of Test 2 may be reduced to no fewer than twenty-four (24) hours.
( )

e. For all testing conducted under these rules, the utility shall have a qualified analyst prepare a report
pursuant to Section 082. ( )

03. Suspended or Limited Testing. With the written agreement of both the utility and the dairy
producer, a stray voltage investigation may be suspended at any point in the investigation. With the written agreement
of both the utility and the dairy producer, the utility may employ a limited set of tests or measurements on a dairy as
part of an intentionally limited evaluation. If tThe utility proposes tomay suspend a stray voltage investigation or to
conduct a limited evaluation, its reasons for doing so shall be set forth in the written agreement between the utility
and as agreed between the utility and the dairy producer. ( )

072. PREPARATION FOR TESTING (RULE 72).
The person performing the tests shall perform the following: ( )

01. Remote Reference Grounding Rod. ( )

a. Remote reference grounding rod(s) shall be installed and penetrate moist soil to a depth of thirty
(30) inches. When practicable, remote reference rods shall be installed at least twenty-five (25) feet away from the
nearest underground conductive electrical equipment of any type or at a distance equal to three (3) to four (4) times
the buried depth of any metallic structure connected to the service entrance neutral. The reference ground rod shall be
located not closer than twenty-five (25) feet from the centerline of a primary electrical conductor right-of-way. A
reference rod shall be located not closer than one hundred (100) feet from the edge of a transmission line right-of-
way. ( )

b. All remote reference grounding rods shall be checked for “remoteness” prior to their use for tests or
measurements and if found to be insufficiently “remote,” a new location for that reference ground rod shall be found
and retested for remoteness. Remoteness of the reference ground shall be determined by measuring the voltage from
the transformer grounding electrode conductor to the remote reference ground. The resistance-to-earth of the
transformer grounding electrode shall be measured. The grounding electrode current shall be measured. Remoteness
is considered adequate if the measured voltage (transformer grounding conductor to reference ground, Vp) is within
twenty percent (20%) of the voltage calculated by multiplying the grounding electrode current by the grounding
electrode resistance-to-earth. ( )

c. If the transformer grounding electrode is within twenty-five (25) feet of other primary or secondary
grounding electrodes, this remoteness test shall be conducted at the first primary system grounding electrode upstream
of the transformer that is greater than twenty-five (25) feet from other primary or secondary system grounding
electrodes. ( )

02. Inspecting the Transformer(s). Prior to testing, the utility transformer shall be inspected,
grounding electrode resistance measured, and any repairs necessary for safety be made and recorded. In the case of a
customer-owned transformer, qualified personnel shall inspect the installation, measure grounding electrode
resistance, and make and record any repairs necessary for safety. Measurements that require contact with utility or
customer-owned primary wires or equipment shall be made by the utility or other qualified personnel. ( )

Commented [OP14]: Aligns better with the practice of
performing “spot checks” requested by dairy producers and
electricians.

03. In-Line Ammeters. If in-line or series ammeters are used, they shall be installed under safe
conditions in accordance with the National Electrical Safety Code NESC and the National Electrical Code NEC with
the entire dairy system or the specific circuit to be tested de-energized. ( )

04. Pre-Test Documentation.( )

a. All pre-test calibration requirements from Section 052 shall be completed and documented. ( )

b. A sketch or drawing of the dairy shall be prepared indicating: ( )

i. The location of the buildings; ( )

ii. Secondary electrical service panels and secondary feeder systems serving cow contact areas;
( )

iii. Transformer(s) and central distribution point; ( )

iv. Existing grounding electrodes (if known); ( )

v. The location of all cow contact points to be tested; ( )

vi. All remote reference grounding rods; and ( )

vii. All primary and secondary neutral test points used in conjunction with the remote reference
grounding rod(s). ( )

c. A listing of planned test points shall be prepared using the applicable form prior to beginning each
test. Each test shall be listed separately and specific reference numbers shall be given to each planned test point.
( )

05. Safety. ( )

a. If the service provider reasonably concludes that a dairy’s noncompliance with the National
Electrical Code NEC poses a significant and immediate safety hazard which prevents completion of any test or
measurement required by these rules, then the service provider’s obligations to proceed under these rules shall be
suspended until the hazard is eliminated. ( )

b. At the discretion of the service provider conducting the test, livestock shall be removed from any
area where electrical equipment or wiring is examined or electrical measurements are taken. Testing may be suspended
if the presence of cows or other animals creates a potential hazard to testing personnel. The locations of electric fences
and other electrified cow control devices shall be noted and de-energized where practical. ( )

073. TEST 1 -- COW CONTACT TEST (RULE 73).

01. Purpose. The purpose of this test is to determine the location(s), if any, where stray current or
voltage exceeds the preventive action level (PAL) and to identify the location(s) at which the cow contact voltage will
be recorded in the forty-eight (48) hour test. ( )

02. Selection of Cow Contact Points. The selection of cow contact points to be tested shall include a
sufficient number of locations reasonably likely to demonstrate the presence of stray voltage or current, if any.
( )

03. Conducting the Test. The voltage across the shunt resistor or current through the shunt resistor

shall be measured between cow contact points as shown in Figure 1. The source resistance shall be calculated during
analysis for all cow contact points.

Figure 1, Cow Contact Test. ( )

a. When using a voltmeter to measure voltage between contact points where one (1) of those points is
the floor surface, the equipment shall be arranged as shown in Figures 1 and 2, using a metal plate, which shall make
a high quality conductive contact with the ground or floor. If the service provider is unsure of having a high quality
conductive contact with the floor or ground, then the procedure described in Paragraph 073.03.c. shall be followed. If
necessary, corrosion shall be removed from the point(s) where test lead(s) make contact with metal equipment.

Figure 2, Cow Contact Voltage Measurement. ( )

Commented [SG15]: All figures and Appendices will be posted to the Commission website at www.puc.idaho,gov

b. When using an in-line milliammeter or a clamp-around milliammeter to measure current between
contact points and one (1) of those points is the floor surface or earth, the equipment shall be arranged as shown in
Figure 3, using a metal plate which shall make high quality conductive contact with the ground or floor. If the service
provider is unsure of having a high quality conductive contact with the floor or ground, then the procedures described
in Paragraph 073.03.c. shall be followed. If necessary, corrosion shall be removed from the point(s) where test lead(s)
make contact with metal equipment.

Figure 3, Set Up for Measuring Current Cow Contact Point to Ground ( )

c. A metal plate used to make an electrical contact with the earth or floor shall be of regular shape
(square, rectangular or round), and shall have a surface area equal to or greater than sixteen (16) square inches (4
inches x 4 inches or equivalent). Place a weight not less than twenty (20) pounds on the metal plate. This weight shall
be applied evenly across the metal plate and not to the adjacent concrete or earth. Place the metal plate a minimum distance of twelve (12) inches from any metal equipment making contact with the floor or earth. ( )

i. Where the metal plate is to be placed on a concrete floor, the surface shall be flat. Clean the floor
surface with a wire stiff brush to remove debris that may add excess resistance. Use water to clean the floor surface at
the point where the metal plate will be placed. Place a paper towel or similar material soaked in saltwater between the
metal plate and the concrete floor. ( )

ii. Where the metal plate is to be placed on the ground or earth surface, the surface shall be flat. Remove
any debris and add water to the area, if necessary, to dampen the soil. The surface of the metal plate that will make
contact with the earth shall be clean and free of corrosion before use. Remove any corrosion, if necessary.
( )

04. Recording the Data. The person conducting this test shall record the location of, and measured
values at, each test point. At each cow contact location, an open circuit voltage reading (Voc) and a voltage with five
hundred (500) ohm nominal shunt resistor placed across the input to the meter shall be taken. These
readings shall be taken with ten (10) seconds or less time between each reading. Alternatively, a current measurement
may be taken in place of the voltage reading . Data for these test points shall be recorded on the
form in Appendix 1. ( )

05. Source Resistance Calculation. The source resistance shall be calculated for each cow
Commented [OP16]: A stiff plastic brush is equally
effective and doesn’t rust or shed short fine metal wires.

contact location measured and the value recorded in Appendix 1. The following formulas shall be used to calculate
source resistance.

( )

074. TEST 2 -- FORTY-EIGHT HOUR TEST (RULE 74).

01. Purpose. The purpose of this test is to determine whether stray current or voltage exceeds the
preventive action level (PAL) at selected location(s) over a forty-eight (48) hour period, subject to Subsection 074.06
and Paragraph 071.02.d. The test also demonstrates whether the primary or secondary sides of the system have a
specific impact on the recorded current or voltage at specific times of day. ( )

02. Setup. A digitizing data recorder with averaging capability and capable of detecting and recording
transient deviations of one-tenth (0.1) second or less in duration shall be used to record the following: ( )

a. Voltage from primary neutral at the transformer to remote reference ground, Vp. ( )

b. Voltage from secondary neutral in the service panel serving the area of the cow contact to remote
reference ground, Vs. ( )
c. Voltage drops (Vps) from primary neutral at the location of connection for Vp to secondary neutral
at the location of the connection for Vs. ( )

d. Cow contact current through (Icc) or voltage across a five hundred (500) ohm resistor at the high
voltage point(s) found in Test 1, Vcc. ( )

03. Measurement Interval. The results of the forty-eight (48) hour test may be highly indicative of the
presence of stray voltage. A recording interval as high as ten (10) seconds may be used provided that transient
deviations of voltage or current of one-tenth (0.1) second or less in duration of voltage or current are recorded to the
maximum ability of the instrument. ( )

04. Measurement at the Cow Contact Point(s). Measurements to the earth or concrete surface shall
be to a metal plate as described in Paragraph 073.03.c. When making measurements to metal objects, corrosion shall
be removed to obtain a low resistance connection. ( )

05. Recording the Data. All of the data gathered by the recording equipment during the forty-eight
(48) hour test including transients shall be downloaded and retained with the records of the investigation. In addition,
the steady-state data shall be summarized in the investigation report. The recorded data shall be made available to the
dairy producer or utility upon request. The person conducting this test shall record the location of, and measured values
at, each test point. The identification of the cow contact point shall be recorded on the form in Appendix 2. Transient
deviations shall be recorded on the supplemental data form, page 3 of 3 in Appendix 2. A plot of the voltage versus
time may be substituted for the recording of measured values in Appendix 2. ( )

06. Reduced Recording Period. If a qualified analyst concludes that remediation by the utility is

required under Paragraph 071.02.d. prior to the completion of a forty-eight (48) hour recording period, the recording
period may be reduced to no fewer than twenty-four (24) hours. ( )

075. TEST 3 -- PRIMARY PROFILE TEST (RULE 75).

01. Purpose. The purpose of this test is to measure or calculate neutral-to-earth voltage (NEV) for a
multi-grounded distribution system.( )

02. Conducting the Test. The primary profile test requires concurrent measurement of the ground
electrode resistance and current at all primary system ground points within three quarters (3/4) of a mile on either side
of all primary service points serving the dairy, or to the end of the line if less than three quarters (3/4) of a mile.
Alternatively, the voltage between a remote grounding rod and the primary ground point being tested may be
measured. ( )

a. This test shall be conducted starting at one (1) end of the distribution system and working toward
the other end along the main primary distribution system. Figure 4 below illustrates the procedure. ( )

i. Where the dairy is served by a dedicated tap of less than one-half (1/2) mile in length from a
distribution line, the neutral-to-earth voltage shall be measured at each primary ground along the tap and along the
distribution line to a distance of three-quarters (3/4) of a mile in each direction from the point of the tap; or ( )

ii. Where a dairy is served by a dedicated tap that extends more than one-half (1/2) mile from the
distribution line, the neutral-to-earth voltage shall be measured at each primary grounding electrode along the tap and
along the distribution line to a distance of one-half (1/2) mile in each direction from the point of the tap. ( )

03. Recording the Data. The person conducting this test shall record the location of, and measured
values at, each test point. Data and calculation results for these test points shall be recorded on the form in Appendix
3.
Figure 4, Primary Profile Test ( )

076. TEST 4 -- SECONDARY NEUTRAL VOLTAGE DROP TEST (RULE 76).

01. Purpose. This test is used to determine the impact of each secondary service on the neutral-to-earth
(NEV) and cow contact voltages on the dairy under controlled conditions. ( )

02. Conducting the Test. This test shall be performed for all service entrances. A proxy load of known
characteristics (such as a resistive load like a one hundred twenty (120) volt, fifteen hundred (1,500) watt hairdryer)
is required for this test. The proxy load must create a known and stable current and subsequent voltage drop for each
neutral serving a main panel, sub-panel or end-of-service area. All service entrances other than that being tested shall be turned “off” to perform this test. A diagram showing the connections and measurement points for this test is shown
in Figure 5.

Figure 5, Secondary Neutral Voltage Drop Test Arrangement. ( )

03. Data Collection. The following data shall be collected for each secondary neutral tested: ( )

a. Gauge and type of neutral wire. ( )

b. Length of neutral wire. ( )

c. Neutral current, Isn. ( )

d. Voltage drop between both ends of the secondary neutral being tested. ( )

e. Cow contact voltage (Vcc) or current (Icc) at the same points used in the forty-eight (48) hour test.
( )

f. Primary neutral at the transformer to reference ground voltage, Vp. ( )
g. Secondary neutral to reference ground voltage, Vs. ( )

04. Measurements. The three (3) voltages (Vcc, Vp and Vs) shall be measured with the proxy load
“off” and “on.” Calculated expected voltage drops (see Appendix 4) shall be compared with measured
voltage drops . If the measured and calculated voltage drops differ significantly, further investigation shall
be undertaken to determine the source of additional voltage drop within the circuit. Neutral current shall be measured

and recorded with the proxy load on (Isn). ( )

05. Recording the Data. Any person conducting this test shall record the location of, and measured
values at, each test point. Data and calculation results for these test points shall be recorded on the form in Appendix
4. ( )

077. TEST 5 -- THE LOAD BOX TEST (RULE 77).
01. Purpose. This test is used to determine the extent to which the primary system contributes to stray
current or voltage at cow contact points. For dairies with three (3) phase balanced primary service, the service provider
shall perform Steps One and Two in Paragraph 077.02.b. below. ( )

02. Conducting the Load Box Test. This test shall be performed at the same time of day as the time(s)
of highest cow contact voltage found in the forty-eight (48) hour test. During this test, voltage and current shall be
measured and recorded at the points indicated in Figure 6.

Figure 6, Load Box Test. ( )

a. The load box test requires the recording of eight (8) data points during each of the five (5) test steps.
The eight (8) data points that shall be measured or calculated and recorded for each step are: ( )

i. Primary line to neutral voltage, . ( )

ii. Load Box Current, Ilb. ( )
iii. Voltage at load box connection to secondary system, Vlb. ( )

iv. Calculate transformer current using . ( )

v. Voltage from primary neutral at the transformer to remote reference ground rod, Vp. ( )

vi. Voltage from secondary neutral in the service panel serving the area of the cow contact to remote
reference ground rod, Vs. ( )

vii. Voltage from primary neutral at the transformer to secondary neutral at the service panel serving
the area of cow contact, Vps. ( )
viii. Cow contact voltage (Vcc) or current (Icc) at the same point(s) used in the forty-eight (48) hour test.
( )

b. Except for dairies with three (3) phase balanced primary service, the following five (5) test steps
shall each be conducted for at least two (2) minutes, and the data shall be recorded for each step: ( )

i. Step One: The load box shall be de-energized, the dairy shall remain “on,” and the data shall be
recorded. ( )

ii. Step Two: The load box shall be de-energized, the dairy shut “off,” and the data shall be recorded.
( )

iii. Step Three: The load box shall be set to half load, the dairy shut “off,” and the data shall be recorded.
( )

iv. Step Four: The load box shall be set to full load, the dairy shut “off,” and the data shall be recorded.
( )

v. Step Five: The load box shall be set to full load, the dairy shall be turned “on,” and the data shall be
recorded. ( )

03. Calculating the K Factor. The K factor is a calculated ratio (Vcc/Vs). The K factor should be less
than one (1) because Vcc (cow contact voltage) should be less than Vs (the dairy ground to reference ground voltage).
If the K factor is greater than one (1), then there is contribution to Vcc from sources other than Vs. ( )

04. Recording the Data. The person conducting this test shall record the location of, and measured
values at, each test point. Data and calculation results for these test points shall be recorded on the form in Appendix
5. ( )

078. TEST 6 -- SIGNATURE TEST (RULE 78).

01. Purpose. This test is used to determine the contribution to stray current or voltage of individual
pieces of equipment operating on the dairy. The test is best performed when there is minimal farm electrical activity.
( )

02. Conducting the Signature Test. During this test, individual pieces of major current drawing
equipment shall be started and stopped. The effects of starting, operating, and stopping each piece of equipment shall
be measured and recorded for a period of operation of at least fifteen (15) seconds. The person conducting the test
shall identify and record the equipment being tested and record the specific times that the equipment was started and
stopped. A digitizing data recorder with averaging capability shall be used to measure and record the required electrical
data. These measurements shall be taken at the same locations at the dairy where measurements were taken for the
purpose of the load box test and forty-eight (48) hour test. ( )

a. Voltage from primary neutral at the transformer to remote reference ground rod, Vp. ( )

b. Secondary neutral at the service panel serving the area of cow contact to remote reference ground
voltage, Vs. ( )

Commented [SG17]: Streamlining the wording

c. Primary neutral voltage drop (Vps) from the location of connection for Vp to secondary neutral
voltage at the location of the connection for Vs. ( )

d. Cow contact voltage (Vcc) or current (Icc) at the preselected point. ( )

03. Recording the Data. All of the data gathered by the recording equipment during the signature test,
including transients shall be downloaded and retained with the records of the investigation. In addition, the steady
state data shall be summarized in the investigation report. The recorded data shall be made available to the dairy producer or utility upon request. The location of all test point(s) shall be recorded on the form in Appendix 6. A plot
of the voltage versus time may be substituted for the recording of measured values on Appendix 6. ( )

079. -- 080. (RESERVED)

ANALYSIS AND REPORTING THE DATA

Rules 81 through 90

081. ANALYZING THE COLLECTED DATA (RULE 81).
01. Cow Contact Points. Examine the data recorded for the forty-eight (48) hour test in Appendix 2
and determine the highest steady state value of cow contact voltage (Vcc) or current (Icc). Determine the value of
primary neutral to reference voltage (Vp) that was present for the highest cow contact value. Record these values on
the data sheet of Appendix 7. These values shall be identified as “test cow contact voltage or current” ( or
) and “primary neutral to reference voltage at time of maximum cow contact voltage or current” (
). The three (3) data sets created from the values are: ( )

a. The primary to reference ground voltage and the cow contact voltage or current measured during
the load box test (Appendix 5) with the farm power “off” and the load box “off” shall be recorded on the data sheet
of Appendix 7 as and either or . ( )
b. The primary to reference ground voltage and the cow contact voltage or current measured with the
load box set at one-half (1/2) load shall be recorded on the data sheet of Appendix 7 as and either
or . ( )

c. The primary to reference ground voltage and the cow contact voltage or current measured with the
load box at maximum shall be recorded on the data sheet of Appendix 7 as and either
or . ( )

02. Contributions to Stray Voltage or Current for Single Phase Dairies. The utility contribution to
cow contact voltage or current shall be determined using the following formula. Compare the values determined to
the preventive action level (PAL).

Utility contribution to

cow contact voltage =

or

Utility contribution to

cow contact current =
( )

03. Contributions to Stray Voltage or Current for Three Phase Dairies. The utility contribution to
cow contact voltage or current for dairies with three (3) phase balanced load service, shall be determined by directly
using the results of the load box test results for Step 1 and Step 2 as specified in Paragraph 077.02.b. ( )

a. The Vcc measured during Step 1 of the load box with the load box “off” and the dairy “on” will be
the total Vcc. ( )

b. The Vcc measured during Step 2 of the load box test with the load box “off” and the dairy “off” is
the contribution to Vcc from the utility, Vccutility. ( )

c. The contribution to Vcc by the dairy is the difference between Vcc and Vccutility, Vccdairy = Vcc
- Vccutility. ( )
082. REPORTING (RULE 82).
Within a reasonable period of time after completion of any tests required to be performed by the utility under these
rules, a qualified analyst shall prepare a written report. The report shall include a summary of the tests performed, a
copy of the sketch or drawing of the dairy prepared pursuant to Section 072, all of the data or results obtained from
the tests, and an analysis of the data or results obtained from the tests. If remediation was required under these rules,
the report shall specify the actions taken or to be taken. The utility shall provide a copy of the written report to the
dairy producer. ( )

083. -- 090. (RESERVED)

REMEDIAL ACTIONS AND COMMISSION PROCEEDINGS
Rules 91 through 92

091. REMEDIATION (RULE 91).

01. Utility System. If the utility is required to conduct remediation, it shall commence such remediation
within five (5) business days. The utility shall diligently pursue to completion remedial procedures which shall reduce,
and are reasonably likely to sustain, that portion of the stray current or voltage attributable to the utility’s distribution system to a level equal to or less than fifty percent (50%) of the preventive action level (PAL). This may include
addressing other off-dairy sources. ( )

02. Other Dairies, Farms and Industrial Sites. If a utility’s contribution to stray voltage exceeds fifty
percent (50%) of the preventive action level (PAL) and the utility determines that another customer is a significant
contributing source of stray voltage, the utility shall notify both the dairy and the other customer in writing.
( )

092. COMMISSION PROCEEDINGS (RULE 92).

01. Filing with the Commission. All petitions seeking relief under Section 61-805, Idaho Code, shall
be filed with the Commission Secretary pursuant to Section 005. Petitions shall conform to IDAPA 31.01.01, “Rules
of Procedure of the Idaho Public Utilities Commission,” Section 053. The petitioner shall file an original and five (5)
copies of the petition. ( )

02. Contents of Petition. The petition shall conform to IDAPA 31.01.01, “Rules of Procedure of the

Idaho Public Utilities Commission,” Section 053. The petition shall contain background information, the date the
notice was filed with the serving utility, a description of the alleged incident(s) of non-compliance with the Stray
Current and Voltage Remediation Act, and the remediation actions (if any) undertaken by either the utility or the dairy.
A copy of the utility’s entire stray voltage report shall accompany the petition. ( )

0XX. FIGURES AND APPENDICES (RULE XX)

01. All figures and appendices can be found on the Commissions website at www.puc.idaho.gov

093. -- 999. (RESERVED)

APPENDIX 1
TEST 1 –
COW CONTACT POINT DATA FORM

Dairy Name: Date:
Dairy Location:
Shunt Resistor: ohm ()

Item
#
Contact
Point
Identifier
Contact
Point
Description
Voltage
Measured
w/o Shunt
Resistor
Voc
Voltage
Current
Measured
w/Shunt
Resistor
Vcc
Source
Resistance
Calculated
Rsource
Comments
1
2

TEST 1 –
COW CONTACT POINT DATA FORM INSTRUCTIONS

1. The total information provided by the contact point identification, the contact point description, and the dairy
sketch(es) shall be sufficient to allow a third party to accurately repeat the test locating the correct cow contact
points for a specific contact voltage.

2. The voltages measured in this test shall be determined using the same instrument(s) for both data points. One
reading shall be taken immediately following the other using the same meter.

3. The actual source resistance is calculated from the known shunt resistance and the measured voltage.

4. Record comments as appropriate or necessary.

or
Commented [SG18]: This is in IDAPA 31.01.01
Commented [SG19]: All figures and Appendices will be
posted to the Commission website at www.puc.idaho,gov

APPENDIX 2

TEST 2 –
“48-HOUR” TEST REPORT FORM 1

Customer Name: Date:
Start Time: Stop Time:
Contact Point Identifier Number

Hour
Time of
Occurrence
(Hr, Min)
of Highest
Steady State
Vcc or Icc

Voltage Across
(Current Thru)
Rshunt
Vcc or Icc

Primary Neutral
to Referenced
Ground
Vp

Secondary
Neutral to
Reference
Ground
Vs

Primary to
Secondary
Voltage Drop
Vps
Duration
Steady State
Vcc or Icc
Exceeded
PAL in One
Hour Period
1
2

TEST 2 - “48-HOUR” TEST REPORT FORM 1
INSTRUCTIONS

Record the following data with a long term digitizing data recorder or its equivalent for a minimum of 48
hours as specified in Rule 074:

a. Voltage from primary neutral to remote reference ground, Vp, at transformer.

b. Secondary neutral to remote reference ground voltage, Vs, at the electrical panel serving the area
for the Vcc or Icc selected.

c. Primary neutral to secondary neutral voltage, Vps, between points of connection for Vp and Vs.

d. Steady state cow contact voltage or current at the preselected point(s) with the highest cow contact
voltage or current recorded in Test 1, Vcc or Icc.

Steady State Data:

Steady state data recorded during the 48-hour test shall be presented in tabular format on Form 1 as described
below, or it shall be presented graphically. Graphical presentation shall include a time scale for the entire recording
period and a clear indication of the steady state readings of Vcc or Icc, Vp, Vs and Vps for the recording intervals.

The scale(s) shall be such that steady state cow contact voltages or currents at or above the PAL are easily identifiable.

If using tabular format, the analyst shall enter data in the table for each hour of the 48 hours of the test in
chronological order. The data recorded in the table shall include: the specific time that the highest steady state value
of Vcc or Icc was recorded in that hour; all four corresponding data points recorded at that time (Vp, Vs, Vps and Vcc
or Icc), and the total time during the hour that the steady state Vcc or Icc exceeded the PAL.

TEST 2 – REPORT FORM 2
SUPPLEMENTAL DATA FOR FARM OWNER
TRANSIENT DEVIATIONS FOUND DURING “48-HOUR” TEST

Customer Name: Date:
Start Time: Stop Time:
Contact Point Identifier Number:

Hour

Time of Highest
Peak Vcc
(Icc)

Highest Voltage
Recorded

Total Number
Transient
Deviations
No. Transient Deviations
Exceeding 1.0 Volts with
Peak Magnitude Greater
than 1.0 Volts
(2.0 milliamps)
1
2

Transient deviations occur due to electrical events such as motor starts. The PAL level is 1.0 volt for steady state
voltages but PAL does not apply to transient voltage deviations.

TEST 2 - “48-HOUR” TEST REPORT FORM 2
INSTRUCTIONS

Recording Transient Data:

For the purpose of identifying and reporting transient deviations, a transient deviation occurs when the
recorded maximum Vcc or Icc in a recording interval exceeds two hundred percent (200%) of the steady state Vcc or
Icc recording during the same recording interval.

Transient data recorded during the 48-hour test shall be presented in tabular format on the “48-hour Test –
Transient Deviation Data” form as described below, or it shall be presented graphically. Graphical presentation shall
include a time scale for the entire recording period and a clear indication of the maximum Vcc or Icc recorded for the
recording intervals. The scale(s) shall be such that Vcc transient deviations at or above two (2.0) volts, or Icc transient
deviations at or above four (4) milliamps, are easily identifiable.

If using a tabular format, the analyst shall enter data in the table for each hour of the 48 hours of the test in
chronological order. The data recorded in the table shall include; the specific time during the hour that the transient
deviation in Vcc or Icc with the largest peak magnitude occurred, the corresponding peak Vcc or Icc, the total number
of transient deviations recorded in that hour, and the total number of transient deviations recorded in that hour with a

peak magnitude of two (2) or more volts for Vcc or four (4) or more milliamps for Icc.

APPENDIX 3

TEST 3 –
PRIMARY PROFILE DATA FORM

Dairy Name:
Dairy Location: Date:

Item
Pole Location
&
Identification
Time
Current
Primary
Ground
Ipg
Resistance
Primary
Ground
Rpg
Calculated
Voltage
(primary
neutral-to-
earth) Vpne
Measured
Voltage
(primary
neutral-to-
earth)
Vpne

# (mA) (Ohm) (V) (V) Notes
1
2

Note: If Vpne is measured it is not required to measure Ipg and Rpg for determination of the calculated Vpne. In cases
where Vpne is calculated the following formula is used:

APPENDIX 4

TEST 4 –
SECONDARY NEUTRAL VOLTAGE DROP TEST

Test Performed by: Date:
Customer Name:
(All other farm loads must be off. Use only one load per circuit.)

_
SITE: 1 2 3 4 5
A Site Location Units
B Circuit Neutral Wire
Gauge
AWG

C Circuit Neutral
AL or CU
D Wire length
(in 100’s ft.)
100 ft.
E /100 ft.
F Total Resistance
(D times E)

G Measured Neutral
Current, Isn
A
H
Calculated Voltage Drop,

(F times G)

V
I
Measured Voltage Drop,

V
J Percent difference
[(H-I)/H]*100
%
Vp load “off” V
Vs load “off” V
Vcc load “off” V
Icc load “off,”
if measured
Vp load “on” V
Vs load “on” V
Vcc load “on” V
Icc load “on,”
if measured

TEST 4 –
SECONDARY NEUTRAL VOLTAGE
DROP TEST
INSTRUCTIONS

ITEM EXPLANATION

A-J Describe load site location, neutral wire gauge, neutral wire length (in 100s of feet), resistance per 100 feet



(see table below), measured neutral current, measured voltage drop, Vp, Vs and Vcc or Icc for load “off”
and load “on.”
ATTACHMENT 2
31.61.01 – RULES FOR THE MEASUREMENT OF
STRAY CURRENT OR VOLTAGE
(THE STRAY VOLTAGE RULES)
GENERAL PROVISIONS
Rules 0 through 11
000. LEGAL AUTHORITY (RULE 0).
Idaho Public Utilities Law, Sections 61-515 and 61-520, Idaho Code, and the Stray Current and Voltage Remediation Act, Section 61-803, Idaho Code. ( )
001. TITLE (RULE 1).
01. Title. The title of these rules is the IDAPA 31.61.01, “Rules for the Measurement of Stray Currentor Voltage” (Stray Voltage Rules). ( )
004. INCORPORATION BY REFERENCE – REFERENCE TO SAFETY CODES (RULE 4).
01. Safety Codes.
a.The National Electrical Safety Code (NESC) is applicable to public utilities and is adopted by
Commission Order, “Safety and Accident Reporting Rules for Utilities Regulated by the Idaho Public Utilities
Commission.” ( )
b.The National Electrical Code (NEC) is applicable to the installation of wires and facilities used to
convey electric current and to apparatus to be operated by such electric current. Adoption of the National Electrical
Code is found at Section 54-1001, Idaho Code, and IDAPA 07.01.06, “Rules Governing the Use of National Electrical
Code,” Section 011. ( )
005. -- 009. (RESERVED)
010. DEFINITIONS (RULE 10).
01. These Rules incorporate by reference s definitions found in Idaho Code 61-802, the NEC, and the
NESC.
02. Ampere. A unit of measure of current. A milliampere is one-one thousandths (1/1,000) of an
ampere. ( )
05.Equipotential Plane (EPP). See NEC 547.2.Means an area where wire mesh or other conductive
elements are embedded in or placed under concrete, bonded to all metal structures and fixed nonelectrical equipment
that may become energized, and connected to the electrical grounding system to prevent a difference in voltage from
developing within the plane. ( )
07. Primary System. High voltage utility electrical system including the generation, transmission and
distribution systems. It also refers to the high voltage side of a distribution transformer.
( )
08. Secondary System. The low-voltage utility electrical system on the secondary side of a distribution
transformer. The dairy’s on-farm system begins on the dairy’s side of the metering points, except for dairies metered
Commented [OP1]: Explicitly adding NEC and NESC as
additional sources of definitions. 
Commented [OP2]: Standard terminology – may be
omitted without creating confusion. (NEC doesn’t include it, 
and we don’t include “volt”.) 
Commented [OP3]: Definition was effectively identical to 
NEC definition. Replacing definition with a citation will keep 
the definition of EPP consistent. 
on the high voltage side of the transformer(s). In the case of dairies metered on the high voltage side, the on-farm
system begins at the transformer’s low-voltage lugs. ( )
09. Service Provider. Means aAny person, company or other legal entity providing stray voltage or
current testing, consulting, measurements, analysis services, construction, or hardware. ( )
10. Shunt Resistor. A physical resistor or combination of resistors used to simulate a dairy cow’s body
resistance, body-to-metal contact resistance, and hoof-to-earth contact resistance between the cow and contact points
during the measurement of cow contact voltage. Aa shunt resistor shall be five hundred (500) ohm plus or minus two
percent (+/- 2%). ( )
11. Source Resistance. Means tThat portion of resistance in the circuit, other than the resistance of the
cow and its contact resistance, when the cow is completing a circuit between contact points. Body-to-metal contact
resistance and hoof-to-earth resistance may represent a portion of the source resistance. ( )
12. Steady State. The value of a current or voltage after an amount of time has passed where all
transients have decayed to a negligible value. ( )
13. Stray Current or Voltage. Stray voltage or current is: ( )
a.Any steady state, sixty (60) hertz (Hz) (including harmonics thereof) root mean square (rms)
alternating current (AC) less than twenty (20) milliamperes (mA) through a five hundred (500) ohm resistor (i.e.,
shunt resistor) connected between cow contact points, as measured by a true rms meter; or ( )
b.Any steady state, sixty (60) Hz (including harmonics thereof), rms AC voltage of less than ten (10)
volts, across (in parallel with) a five hundred (500) ohm resistor (i.e., shunt resistor) connected between cow contact
points, as measured by a true rms meter. ( )
c.Stray current and voltage is a normal, inherent and unavoidable result of electricity traveling through
grounded electrical systems, including a dairy producer’s on-farm system and a utility’s distribution system. These
systems are required by the (NEC) and the (NESC) to be grounded to the earth to ensure safety and reliability. ( )
d.Unless the context otherwise requires, the term “stray voltage” shall mean stray current or stray
voltage. ( )
14.Tests, Measurements, Procedures and Analysis. Means aAny or all of the stray voltage testing,
measurement, work and work product defined in these rules. ( )
15. Transient or Transient Deviation. Transient or transient deviation means a A non-steady state
increase or spike in voltage or current. For the purpose of identifying and reporting transients in cow contact voltage
(Vcc) or current (Icc), a transient occurs when the recorded maximum Vcc or Icc in a recording interval exceeds two
hundred percent (200%) of the steady state Vcc or Icc recorded during the same recording interval. ( )
16. Utility. Means aA public electric utility as defined in Section 61-332A, Idaho Code. ( )
012. -- 020. (RESERVED)
APPLICABILITY AND ADMISSIBILITY
Rules 21 through 30
021. UTILITY (RULE 21).A utility measuring or testing for stray voltage or current at the request of a dairy producer, as directed by the
Commission or on its own initiative, shall conduct such measurements in accordance with these rules. ( )
Commented [OP4]: Clarification of original definition.
Cows don’t make a nearly zero‐ohm connection to their 
environment like metal voltage test‐leads can. The 500‐ohm 
shunt resistor is intended as a substitute for both the cow’s 
internal body resistance and any contact resistance 
between a cow and its environment. (ref. IEEE Std. 1695‐
2016 section 5.5.1.4, and USDA 696 pg 5‐5, 5‐10. 
Commented [OP5]: See above – contact resistance is
included in the shunt resistor for measurement purposes. 
Commented [OP6]: Defined in IDAPA 61‐802
Commented [OP7]: Defined and described in IDAPA 61‐
802. Note – (d) should be kept. 
022. DAIRY PRODUCER (RULE 22).
01.Serving Notice on the Utility. A dairy producer providing written notice to a utility pursuant to
Section 61-804, Idaho Code, shall specify why the dairy producer believes its dairy cows are being affected by
electrical energy attributable to the utility. A dairy producer may provide such notice with or without first having
conducted tests or measurements of stray voltage. ( )
02. Cooperation. When a written notice is filed with the utility, the dairy is obligated to make any
contact point(s), service panels, grounding rods or other electrical equipment at the dairy available to the utility for
measuring and testing. The utility shall provide reasonable notice and cooperate with the dairy producer to establish an appropriate time to conduct the tests and measurements. The dairy shall cooperate with the utility so that all tests
and measurements necessary to identify the existence and magnitude of stray current or voltage, if any, are completed
within fourteen (14) days of the utility’s receipt of such notice. ( )
023. SERVICE PROVIDERS (RULE 23). Any person performing any stray voltage measurement or test on behalf of a utility or a dairy shall be deemed a service
provider andAll service providers shall follow these rules. ( )
024. ADMISSIBILITY (RULE 24).
Only tests and measurements made in compliance with these rules shall be admissible before the Commission or in
any civil action. ( )
025. -- 030. (RESERVED)
QUALIFICATIONS OF PERSONS
PERFORMING AND ANALYZING
RESULTS OF STRAY VOLTAGE TESTS
Rules 31 through 40
031. PERFORMANCE OF TESTS AND MEASUREMENTS (RULE 31). Measuring and testing for stray voltage under these rules for consideration by the Commission shall be performed by
a qualified testing professional, such as:
01. Professional Engineer. A professional engineer, licensed in any state, who has completed no fewer
than forty-eight (48) hours of Commission-approved stray voltage training and who has been involved in no fewer than five (5) prior investigations involving the measurement or testing of stray voltage. ( )
02. Master Electrician. A master electrician, licensed in any state, who has completed no fewer than
forty-eight (48) hours of Commission-approved stray voltage training and who has been involved in no fewer than
five (5) prior investigations involving the measurement or testing of stray voltage. ( )
03. Technician. A technician who, under the supervision of a person presumed qualified under
Subsections 031.01 and 031.02, has completed no fewer than eight (8) hours of Commission-approved stray voltage
training and who has been involved in no fewer than five (5) prior investigations involving the measurement or testing
of stray voltage. ( )
032. DATA ANALYSIS (RULE 32).
Analysis of data under these rules, for consideration by the Commission, shall be performed by a qualified analyst. A
professional engineer, licensed in any state, who has completed no fewer than forty-eight (48) hours of stray voltage
training and who has been involved in no fewer than five (5) prior investigations involving measurement or testing of
stray voltage shall be presumed to be a qualified analyst. ( )
033. PERSONS OTHERWISE QUALIFIED (RULE 33).
A person who does not satisfy the qualifications in Sections 031 and 032, may nonetheless be determined by the
Commented [OP8]: The “why” requirement for the
notice is included in IDAPA 61‐804. 
Commented [OP9]: Service Providers is already defined
in the definitions section. This applicability section didn’t 
change that definition. 
Commented [OP10]: This requirement is included in
IDAPA 61‐803. 
Commission to be a qualified testing professional or a qualified analyst if, on motion of any party, the Commission
finds that person otherwise possesses the knowledge, skill, experience, training, or education that qualifies that person
to offer expert testimony before the Commission. ( )
034. -- 050. (RESERVED)
CALIBRATION OF AND EQUIPMENT USED FOR MEASURING
AND RECORDING
VOLTAGE, CURRENT, AND RESISTANCE
Rules 51 through 60
051. GENERAL REQUIREMENTS FOR STRAY VOLTAGE MEASURING AND RECORDING
EQUIPMENT (RULE 51).
Equipment used for the measurement or testing of stray voltage, current, and resistance shall meet the following
criteria: ( )
01. Resolution and Accuracy. The accuracy and resolution of any instrument used to measure or record
cow contact voltage or current, shall limit the error to five percent (5%) or less at one volt (1 V) or two milliampere
(2 mA). ( )
02. Voltage Measurement. Instruments used to measure cow contact voltage shall be capable of
separating and independently measuring alternating current (AC) and direct current (DC) voltages. These instruments
shall have a minimum internal impedance of ten thousand (10,000) ohm and shall be capable of measuring the true-
rms voltage. ( )
03. Current Measurement. A clamp-on ammeter, a digital multi-meter (DMM) with clamp-on device,
or an in-line ammeter shall be used to measure current through a conductor or resistor connected between two (2)
points. The meters shall be capable of separating and independently measuring alternating current (AC) and direct
current (DC) and shall be capable of measuring the true-rms current. Care must be taken to assure that clamp-on
ammeters used have the required resolution and accuracy. ( )
04. Resistance Measurement. Resistance shall be measured using either a volt ohmmeter (VOM) or a
DMM. Resolution shall be to the level of one (1) ohm or less when measuring a resistance of less than one thousand
(1,000) ohm. Accuracy shall be within plus or minus five (+/-5) ohm for a five hundred (500) ohm resistance.
( )
05. Resistance-to-Earth Measurement. Grounding electrode resistance-to-earth measurements shall
be made with a three- (3) point fall-of-potential instrument or a clamp-on resistance-to-earth tester. ( )
052.CALIBRATION REQUIREMENTS (RULE 52).
01. Measuring Equipment Calibration. All measuring equipment shall be calibrated according to the
manufacturer’s recommended calibration schedule, but no less than annually, to meet the manufacturer’s
specifications for the accuracy and resolution of the equipment. Measuring equipment shall not be used after its next
“calibration due” date for measurements or tests conducted during a stray voltage investigation. Calibration shall be
performed by either: ( )
a.The manufacturer of the equipment, who shall certify that the equipment meets the manufacturer’s
specifications for accuracy and resolution; or ( )
b.A laboratory currently certified as meeting all applicable Institute of Electrical and Electronic
Engineers (IEEE) and International Organization for Standards (ISO) standards. ( )
Commented [OP11]: Clarification for accuracy. There
may be multiple current paths between two points. A 
clamp‐on ammeter only measures the current in the 
conductor(s) it is clamped around. 
02. Calibration Certificates. The service provider performing the tests and measurements shall
maintain certificates from the manufacturer or the calibration laboratory demonstrating compliance with calibration
requirements. ( )
03. Field Check. Before voltage or current measurement or testing is performed, the instrument shall
be field checked by comparing measurements to those of other instruments or against a known source. ( )
053. REQUIREMENTS FOR MONITORING AND RECORDING DEVICES (RULE 53).
Digital recording devices shall be used for the purpose of recording current and voltage for extended periods, such as
the forty-eight (48) hour test. The recording devices shall have the same level of resolution and accuracy as the meters being used for the measurements. Monitoring systems, which combine measuring and recording functions in a single
instrument, shall have the same level of resolution and accuracy as specified in Section 051. Recording devices and
monitoring systems shall be capable of recording transient deviations of one-tenth (0.1) second or less in duration
from the steady state. Digital recording devices, which have deviation settings, shall permit the deviation setting to be
set “low” enough to meet the resolution and accuracy requirements in Subsection 051.01 of these rules. All recording devices shall be able to log the time and date of all data recorded and shall have their internal clocks synchronized.
( )
054. REQUIREMENTS FOR LOAD BOXES (RULE 54).
01. Volts. A load box shall be a primarily non-inductive nominal two hundred forty (240) volt,
resistance heating type load with a minimum nominal full load of eighteen (18) kilowatts (kW). ( )
02. Split-Load. A load box shall be capable of operating at two (2) or more load settings, including
approximately fifty percent (50%) and one hundred percent (100%) of the load box’s rated total load. ( )
055. -- 070. (RESERVED)
TESTING AND MEASUREMENT PROCEDURES
Rules 71 through 80
071. STRAY CURRENT OR VOLTAGE TESTS (RULE 71).
Subject to Subsection 071.02, there are six (6) tests used to detect and measure stray current or voltage. ( )
01. Scheduling of Stray Voltage Tests. Efforts shall be made to perform the tests under conditions
substantially similar to those conditions existing at the time(s) the dairy producer believes stray voltage to be a
problem. ( )
a.Test 1 - Cow Contact Test; ( )
b.Test 2 - Forty-Eight (48) Hour Test; ( )
c.Test 3 - Primary Profile Test; ( )
d.Test 4 - Secondary Neutral Voltage Drop Test; ( )
e.Test 5 - Load Box Test; and ( )
f.Test 6 - Signature Test. ( )
02. Testing Sequence. Test 1 shall be performed first. Tests 1 and 2 are used to determine the presence
and level of stray voltage and shall be performed in all investigations, subject to the provisions of Subsection 071.03.
Tests 3, 4, 5, and 6 may be performed in any order and may be performed without first determining that these tests are
required under Paragraph 071.02.b. Tests 3, 4, 5, and 6 may be performed prior to starting the recording for Test 2 or
while Test 2 is in progress. Test 2 may be interrupted as necessary to conduct Tests 4, 5, and 6, or for review and
analysis of the data recorded up to that point. ( )
a.If the results from Tests 1 and 2 indicate that stray voltage does not exceed the preventive action
level (PAL), the utility has no further testing or remediation obligations under these rules during this test cycle.
( )
b.If the PAL is exceeded, the utility shall perform the remaining four (4) tests except as provided in
Subsection 071.03. The utility shall also perform analysis to determine whether the portion of the stray current or
voltage attributable to an off-farm source exceeds fifty percent (50%) of the PAL. ( )
c.If the PAL is exceeded, and the portion of the stray current or voltage attributable to an off-farm
source does not exceed fifty percent (50%) of the PAL, the utility has no further testing or remediation obligations.
( )
d.If the PAL is exceeded, and the portion of the stray current or voltage attributable to an off-farmsource exceeds fifty percent (50%) of the PAL, the utility shall conduct remediation pursuant to Section 091. Under
this condition, the forty-eight (48) hour recording of Test 2 may be reduced to no fewer than twenty-four (24) hours.
( )
e.For all testing conducted under these rules, the utility shall have a qualified analyst prepare a report
pursuant to Section 082. ( )
03.Suspended or Limited Testing. With the written agreement of both the utility and the dairy
producer, a stray voltage investigation may be suspended at any point in the investigation. With the written agreement
of both the utility and the dairy producer, the utility may employ a limited set of tests or measurements on a dairy as
part of an intentionally limited evaluation. If tThe utility proposes tomay suspend a stray voltage investigation or to
conduct a limited evaluation, its reasons for doing so shall be set forth in the written agreement between the utility
and as agreed between the utility and the dairy producer. ( )
072. PREPARATION FOR TESTING (RULE 72).
The person performing the tests shall perform the following: ( )
01. Remote Reference Grounding Rod. ( )
a.Remote reference grounding rod(s) shall be installed and penetrate moist soil to a depth of thirty
(30) inches. When practicable, remote reference rods shall be installed at least twenty-five (25) feet away from the
nearest underground conductive electrical equipment of any type or at a distance equal to three (3) to four (4) times
the buried depth of any metallic structure connected to the service entrance neutral. The reference ground rod shall be
located not closer than twenty-five (25) feet from the centerline of a primary electrical conductor right-of-way. A
reference rod shall be located not closer than one hundred (100) feet from the edge of a transmission line right-of-
way. ( )
b.All remote reference grounding rods shall be checked for “remoteness” prior to their use for tests or
measurements and if found to be insufficiently “remote,” a new location for that reference ground rod shall be found
and retested for remoteness. Remoteness of the reference ground shall be determined by measuring the voltage from
the transformer grounding electrode conductor to the remote reference ground. The resistance-to-earth of the
transformer grounding electrode shall be measured. The grounding electrode current shall be measured. Remoteness
is considered adequate if the measured voltage (transformer grounding conductor to reference ground, Vp) is within
twenty percent (20%) of the voltage calculated by multiplying the grounding electrode current by the grounding
electrode resistance-to-earth. ( )
c. If the transformer grounding electrode is within twenty-five (25) feet of other primary or secondary
grounding electrodes, this remoteness test shall be conducted at the first primary system grounding electrode upstream
of the transformer that is greater than twenty-five (25) feet from other primary or secondary system grounding
electrodes. ( )
Commented [OP12]: Aligns better with the practice of
performing “spot checks” requested by dairy producers and 
electricians. 
02.Inspecting the Transformer(s). Prior to testing, the utility transformer shall be inspected,
grounding electrode resistance measured, and any repairs necessary for safety be made and recorded. In the case of a
customer-owned transformer, qualified personnel shall inspect the installation, measure grounding electrode
resistance, and make and record any repairs necessary for safety. Measurements that require contact with utility or
customer-owned primary wires or equipment shall be made by the utility or other qualified personnel. ( )
03.In-Line Ammeters. If in-line or series ammeters are used, they shall be installed under safe
conditions in accordance with NESC and the NEC with the entire dairy system or the specific circuit to be tested de-
energized. ( )
04. Pre-Test Documentation.()
a.All pre-test calibration requirements from Section 052 shall be completed and documented.
( )
b.A sketch or drawing of the dairy shall be prepared indicating:( )
i. The location of the buildings; ( )
ii. Secondary electrical service panels and secondary feeder systems serving cow contact areas;
( )
iii. Transformer(s) and central distribution point;( )
iv. Existing grounding electrodes (if known); ( )
v. The location of all cow contact points to be tested; ( )
vi. All remote reference grounding rods; and ( )
vii.All primary and secondary neutral test points used in conjunction with the remote reference
grounding rod(s).()
c.A listing of planned test points shall be prepared using the applicable form prior to beginning each
test. Each test shall be listed separately, and specific reference numbers shall be given to each planned test point.
( )
05. Safety. ( )
a.If the service provider reasonably concludes that a dairy’s noncompliance with the NEC poses a
significant and immediate safety hazard which prevents completion of any test or measurement required by these
rules, then the service provider’s obligations to proceed under these rules shall be suspended until the hazard is
eliminated. ( )
b.At the discretion of the service provider conducting the test, livestock shall be removed from anyarea where electrical equipment or wiring is examined, or electrical measurements are taken. Testing may be
suspended if the presence of cows or other animals creates a potential hazard to testing personnel. The locations of
electric fences and other electrified cow control devices shall be noted and de-energized where practical. ( )
073. TEST 1 -- COW CONTACT TEST (RULE 73).
01. Purpose. This test is to determine the location(s), if any, where stray current or voltage exceeds the
PAL and to identify the location(s) at which the cow contact voltage will be recorded in the forty-eight (48) hour test.
( )
02. Selection of Cow Contact Points. The selection of cow contact points to be tested shall include a
sufficient number of locations reasonably likely to demonstrate the presence of stray voltage or current, if any.
( )
03.Conducting the Test. The voltage across the shunt resistor or current through the shunt resistor
shall be measured between cow contact points as shown in Figure 1. The source resistance shall be calculated during
analysis for all cow contact points.
a.When using a voltmeter to measure voltage between contact points where one (1) of those points isthe floor surface, the equipment shall be arranged as shown in Figures 1 and 2, using a metal plate, which shall make
a high quality conductive contact with the ground or floor. If the service provider is unsure of having a high-quality
conductive contact with the floor or ground, then the procedure described in Paragraph 073.03.c. shall be followed. If
necessary, corrosion shall be removed from the point(s) where test lead(s) make contact with metal equipment.
b.When using an in-line milliammeter or a clamp-around milliammeter to measure current between
contact points and one (1) of those points is the floor surface or earth, the equipment shall be arranged as shown in
Figure 3, using a metal plate which shall make high quality conductive contact with the ground or floor. If the service
provider is unsure of having a high-quality conductive contact with the floor or ground, then the procedures described
in Paragraph 073.03.c. shall be followed. If necessary, corrosion shall be removed from the point(s) where test lead(s)
make contact with metal equipment.
c. A metal plate used to make an electrical contact with the earth or floor shall be of regular shape
(square, rectangular or round), and shall have a surface area equal to or greater than sixteen (16) square inches (4
inches x 4 inches or equivalent). Place a weight not less than twenty (20) pounds on the metal plate. This weight shall
be applied evenly across the metal plate and not to the adjacent concrete or earth. Place the metal plate a minimum
distance of twelve (12) inches from any metal equipment making contact with the floor or earth. ( )

i. Where the metal plate is to be placed on a concrete floor, the surface shall be flat. Clean the floor
surface with a wire stiff brush to remove debris that may add excess resistance. Use water to clean the floor surface at
the point where the metal plate will be placed. Place a paper towel or similar material soaked in saltwater between the
metal plate and the concrete floor. ( )
ii. Where the metal plate is to be placed on the ground or earth surface, the surface shall be flat. Remove
any debris and add water to the area, if necessary, to dampen the soil. The surface of the metal plate that will make
contact with the earth shall be clean and free of corrosion before use. Remove any corrosion, if necessary.
( )
04.Recording the Data. The person conducting this test shall record the location of, and measured
values at, each test point. At each cow contact location, an open circuit voltage reading (Voc) and a voltage with five
hundred (500) ohm nominal shunt resistor placed across the input to the meter shall be taken. These
readings shall be taken with ten (10) seconds or less time between each reading. Alternatively, a current measurement
may be taken in place of the voltage reading . Data for these test points shall be recorded on the
form in Appendix 1. ( )
05. Source Resistance Calculation. The source resistance shall be calculated for each cow
contact location measured and the value recorded in Appendix 1. The following formulas shall be used to calculate
source resistance.
( )
074. TEST 2 -- FORTY-EIGHT HOUR TEST (RULE 74).
01.Purpose. This test is to determine whether stray current or voltage exceeds the (PAL) at selectedlocation(s) over a forty-eight (48) hour period, subject to Subsection 074.06 and Paragraph 071.02.d. The test also
demonstrates whether the primary or secondary sides of the system have a specific impact on the recorded current or
voltage at specific times of day. ( )
02.Setup. A digitizing data recorder with averaging capability and capable of detecting and recording
transient deviations of one-tenth (0.1) second or less in duration shall be used to record the following: ( )
a.Voltage from primary neutral at the transformer to remote reference ground, Vp. ( )
b.Voltage from secondary neutral in the service panel serving the area of the cow contact to remote
reference ground, Vs. ( )
c.Voltage drops (Vps) from primary neutral at the location of connection for Vp to secondary neutral
at the location of the connection for Vs. ( )
d.Cow contact current through (Icc) or voltage across a five hundred (500) ohm resistor at the high
Commented [OP13]: A stiff plastic brush is equally
effective and doesn’t rust or shed short fine metal wires. 
voltage point(s) found in Test 1, Vcc. ( )
03. Measurement Interval. The results of the forty-eight (48) hour test may be highly indicative of the
presence of stray voltage. A recording interval as high as ten (10) seconds may be used provided that transient
deviations of voltage or current of one-tenth (0.1) second or less in duration of voltage or current are recorded to the
maximum ability of the instrument. ( )
04.Measurement at the Cow Contact Point(s). Measurements to the earth or concrete surface shall
be to a metal plate as described in Paragraph 073.03.c. When making measurements to metal objects, corrosion shall
be removed to obtain a low resistance connection. ( )
05. Recording the Data. Data gathered by the recording equipment during the forty-eight (48) hour
test including transients shall be downloaded and retained with the records of the investigation. In addition, the steady-
state data shall be summarized in the investigation report. The recorded data shall be made available to the dairy
producer or utility upon request. The person conducting this test shall record the location of, and measured values at, each test point. The identification of the cow contact point shall be recorded on the form in Appendix 2. Transient
deviations shall be recorded on the supplemental data form, page 3 of 3 in Appendix 2. A plot of the voltage versus
time may be substituted for the recording of measured values in Appendix 2. ( )
06. Reduced Recording Period. If a qualified analyst concludes that remediation by the utility is
required under Paragraph 071.02.d. prior to the completion of a forty-eight (48) hour recording period, the recording
period may be reduced to no fewer than twenty-four (24) hours. ( )
075. TEST 3 -- PRIMARY PROFILE TEST (RULE 75).
01. Purpose. This test is to measure or calculate neutral-to-earth voltage (NEV) for a multi-grounded
distribution system.()
02.Conducting the Test. The primary profile test requires concurrent measurement of the ground
electrode resistance and current at all primary system ground points within three quarters (3/4) of a mile on either side
of all primary service points serving the dairy, or to the end of the line if less than three quarters (3/4) of a mile.
Alternatively, the voltage between a remote grounding rod and the primary ground point being tested may be
measured. ( )
a.This test shall be conducted starting at one (1) end of the distribution system and working toward
the other end along the main primary distribution system. Figure 4 below illustrates the procedure. ( )
i.Where the dairy is served by a dedicated tap of less than one-half (1/2) mile in length from a
distribution line, the neutral-to-earth voltage shall be measured at each primary ground along the tap and along the
distribution line to a distance of three-quarters (3/4) of a mile in each direction from the point of the tap; or ( )
ii. Where a dairy is served by a dedicated tap that extends more than one-half (1/2) mile from the
distribution line, the neutral-to-earth voltage shall be measured at each primary grounding electrode along the tap and
along the distribution line to a distance of one-half (1/2) mile in each direction from the point of the tap. ( )
03.Recording the Data. The person conducting this test shall record the location of, and measuredvalues at, each test point. Data and calculation results for these test points shall be recorded on the form in Appendix
3.
076. TEST 4 -- SECONDARY NEUTRAL VOLTAGE DROP TEST (RULE 76).
01.Purpose. This test is used to determine the impact of each secondary service on the neutral-to-earth
(NEV) and cow contact voltages on the dairy under controlled conditions. ( )
02. Conducting the Test. This test shall be performed for all service entrances. A proxy load of known
characteristics (such as a resistive load like a one hundred twenty (120) volt, fifteen hundred (1,500) watt hairdryer)
is required for this test. The proxy load must create a known and stable current and subsequent voltage drop for each
neutral serving a main panel, sub-panel or end-of-service area. All service entrances other than that being tested shall
be turned “off” to perform this test. A diagram showing the connections and measurement points for this test is shown
in Figure 5.
03. Data Collection. The following data shall be collected for each secondary neutral tested: ( )
a.Gauge and type of neutral wire.( )
b.Length of neutral wire. ( )
c.Neutral current, Isn. ( )
d.Voltage drop between both ends of the secondary neutral being tested. ( )
e.Cow contact voltage (Vcc) or current (Icc) at the same points used in the forty-eight (48) hour test. ( )
f.Primary neutral at the transformer to reference ground voltage, Vp. ( )
g.Secondary neutral to reference ground voltage, Vs. ( )
04. Measurements. The three (3) voltages (Vcc, Vp and Vs) shall be measured with the proxy load
“off” and “on.” Calculated expected voltage drops (see Appendix 4) shall be compared with measured
voltage drops . If the measured and calculated voltage drops differ significantly, further investigation shall
be undertaken to determine the source of additional voltage drop within the circuit. Neutral current shall be measured
and recorded with the proxy load on (Isn). ( )
05. Recording the Data. Any person conducting this test shall record the location of, and measured
values at, each test point. Data and calculation results for these test points shall be recorded on the form in Appendix
4. ( )
077. TEST 5 -- THE LOAD BOX TEST (RULE 77).
01.Purpose. To determine the extent to which the primary system contributes to stray current or voltage
at cow contact points. For dairies with three (3) phase balanced primary service, the service provider shall perform
Steps One and Two in Paragraph 077.02.b. below. ( )
02. Conducting the Load Box Test. This test shall be performed at the same time of day as the time(s)
of highest cow contact voltage found in the forty-eight (48) hour test. During this test, voltage and current shall be
measured and recorded at the points indicated in Figure 6.
a.The load box test requires the recording of eight (8) data points during each of the five (5) test steps.
The eight (8) data points that shall be measured or calculated and recorded for each step are: ( )
i. Primary line to neutral voltage, . ( )
ii. Load Box Current, Ilb. ( )
iii. Voltage at load box connection to secondary system, Vlb. ( )
iv. Calculate transformer current using . ( )
v. Voltage from primary neutral at the transformer to remote reference ground rod, Vp. ( )
vi.Voltage from secondary neutral in the service panel serving the area of the cow contact to remote
reference ground rod, Vs. ( )
vii. Voltage from primary neutral at the transformer to secondary neutral at the service panel serving
the area of cow contact, Vps. ( )
viii. Cow contact voltage (Vcc) or current (Icc) at the same point(s) used in the forty-eight (48) hour test.
( )
b.Except for dairies with three (3) phase balanced primary service, the following five (5) test stepsshall each be conducted for at least two (2) minutes, and the data shall be recorded for each step: ( )
i. Step One: The load box shall be de-energized, the dairy shall remain “on,”( )
ii. Step Two: The load box shall be de-energized, the dairy shut “off,”( )
iii. Step Three: The load box shall be set to half load, the dairy shut “off,” ( )
iv. Step Four: The load box shall be set to full load, the dairy shut “off,” ( )
v. Step Five: The load box shall be set to full load, the dairy shall be turned “on,” ( )
03. Calculating the K Factor. The K factor is a calculated ratio (Vcc/Vs). The K factor should be less
than one (1) because Vcc (cow contact voltage) should be less than Vs (the dairy ground to reference ground voltage).
If the K factor is greater than one (1), then there is contribution to Vcc from sources other than Vs. ( )
04.Recording the Data. The person conducting this test shall record the location of, and measured
values at, each test point. Data and calculation results for these test points shall be recorded on the form in Appendix
5. ( )
078. TEST 6 -- SIGNATURE TEST (RULE 78).
01. Purpose. This test is used to determine the contribution to stray current or voltage of individual
pieces of equipment operating on the dairy. The test is best performed when there is minimal farm electrical activity.
( )
02.Conducting the Signature Test. During this test, individual pieces of major current drawing
equipment shall be started and stopped. The effects of starting, operating, and stopping each piece of equipment shall
be measured and recorded for a period of operation of at least fifteen (15) seconds. The person conducting the test
shall identify and record the equipment being tested and record the specific times that the equipment was started and
stopped. A digitizing data recorder with averaging capability shall be used to measure and record the required electrical
data. These measurements shall be taken at the same locations at the dairy where measurements were taken for the
purpose of the load box test and forty-eight (48) hour test. ( )
a.Voltage from primary neutral at the transformer to remote reference ground rod, Vp. ( )
b.Secondary neutral at the service panel serving the area of cow contact to remote reference ground
voltage, Vs. ( )
c.Primary neutral voltage drop (Vps) from the location of connection for Vp to secondary neutral
voltage at the location of the connection for Vs. ( )
d.Cow contact voltage (Vcc) or current (Icc) at the preselected point. ( )
03. Recording the Data. All of the data gathered by the recording equipment during the signature test,
including transients shall be downloaded and retained with the records of the investigation. In addition, the steady
state data shall be summarized in the investigation report. The recorded data shall be made available to the dairy
producer or utility upon request. The location of all test point(s) shall be recorded on the form in Appendix 6. A plot
of the voltage versus time may be substituted for the recording of measured values on Appendix 6. ( )
079. -- 080. (RESERVED)
ANALYSIS AND REPORTING THE DATA
Rules 81 through 90
081. ANALYZING THE COLLECTED DATA (RULE 81).
01. Cow Contact Points. Examine the data recorded for the forty-eight (48) hour test in Appendix 2
and determine the highest steady state value of cow contact voltage (Vcc) or current (Icc). Determine the value of
primary neutral to reference voltage (Vp) that was present for the highest cow contact value. Record these values on
the data sheet of Appendix 7. These values shall be identified as “test cow contact voltage or current” ( or
) and “primary neutral to reference voltage at time of maximum cow contact voltage or current” (
). The three (3) data sets created from the values are: ( )
a.The primary to reference ground voltage and the cow contact voltage or current measured during
the load box test (Appendix 5) with the farm power “off” and the load box “off” shall be recorded on the data sheet
of Appendix 7 as and either or . ( )
b.The primary to reference ground voltage and the cow contact voltage or current measured with the
load box set at one-half (1/2) load shall be recorded on the data sheet of Appendix 7 as and either
or . ( )
c.The primary to reference ground voltage and the cow contact voltage or current measured with the
load box at maximum shall be recorded on the data sheet of Appendix 7 as and either
or . ( )
02. Contributions to Stray Voltage or Current for Single Phase Dairies. The utility contribution to
cow contact voltage or current shall be determined using the following formula. Compare the values determined to
the preventive action level (PAL).
Utility contribution to
cow contact voltage =
or
Utility contribution to
cow contact current =
( )
03. Contributions to Stray Voltage or Current for Three Phase Dairies. The utility contribution to
cow contact voltage or current for dairies with three (3) phase balanced load service, shall be determined by directly
using the results of the load box test results for Step 1 and Step 2 as specified in Paragraph 077.02.b. ( )
a.The Vcc measured during Step 1 of the load box with the load box “off” and the dairy “on” will be the total Vcc. ( )
b.The Vcc measured during Step 2 of the load box test with the load box “off” and the dairy “off” is
the contribution to Vcc from the utility, Vccutility. ( )
c.The contribution to Vcc by the dairy is the difference between Vcc and Vccutility, Vccdairy = Vcc
- Vccutility. ( )
082.REPORTING (RULE 82).
Within a reasonable period of time after completion of any tests required to be performed by the utility under these
rules, a qualified analyst shall prepare a written report. The report shall include a summary of the tests performed, a
copy of the sketch or drawing of the dairy prepared pursuant to Section 072, all of the data or results obtained from
the tests, and an analysis of the data or results obtained from the tests. If remediation was required under these rules,
the report shall specify the actions taken or to be taken. The utility shall provide a copy of the written report to the
dairy producer. ( )
083. -- 090. (RESERVED)
REMEDIAL ACTIONS AND COMMISSION PROCEEDINGS
Rules 91 through 92
091.REMEDIATION (RULE 91).
01. Utility System. If the utility is required to conduct remediation, it shall commence such remediation
within five (5) business days. The utility shall diligently pursue to completion remedial procedures which shall reduce,
and are reasonably likely to sustain, that portion of the stray current or voltage attributable to the utility’s distribution
system to a level equal to or less than fifty percent (50%) of the PAL. This may include addressing other off-dairy
sources. ( )
02. Other Dairies, Farms and Industrial Sites. If a utility’s contribution to stray voltage exceeds fiftypercent (50%) of the PAL and the utility determines that another customer is a significant contributing source of stray
voltage, the utility shall notify both the dairy and the other customer in writing.
( )
092.COMMISSION PROCEEDINGS (RULE 92).
01.Filing with the Commission. All petitions seeking relief under Section 61-805, Idaho Code, shall
be filed with the Commission Secretary pursuant to Section 005. Petitions shall conform to IDAPA 31.01.01 Section
053. The petitioner shall file an original and five (5) copies of the petition. ( )
0XX. FIGURES AND APPENDICES (RULE XX)
01.All figures and appendices can be found on the Commissions website at www.puc.idaho.gov
093. -- 999. (RESERVED)
ATTACHMENT 3
Voltmeter
Stanchions
Weighted Copper Plate 16 square inch minimum
Voltage from stanchion to floor
Milliammeter
Steel Pipe
R
500Ω
Copper plate on wet concrete floor or earth
Voltmeter
500Ω Shunt Resistor
8.888.88
Ipn IpnIpn IpnIpn
Ipg Ipg Ipg Ipg
Resistance and current meter
Measure I and R
Referenced Ground Rod
Voltmeter
25 ftminimum
A voltmeter may be used to determine voltage directly
Vcc (recorded on dairy)
Service Panel
BarnShop
Hair dryer loadHair dryer load
Voltage Drop
Distance B
Distance A
Voltage Drop
Load Box
Vp
Vps
Vs
Remote Reference Rod Vcc (recorded on dairy)
Service Panel
Ip
Ipn Isn net
Isn