public input no. 140-nfpa 79-2016 [ global input ]...nema ics 2, industrial control and systems:...

Public Input No. 140-NFPA 79-2016 [ Global Input ]

Type your content here ...globably change "cableless" to "wireless"

9.2.5.1.2

9.2.7

9.2.7.1

9.2.7.2

9.2.7.3.1

9.2.7.3.1(2)

9.2.7.3.1(4)

9.2.7.3.2

9.2.7.3.2(2)

A.3.3.14 ,multiple but has separate PI

Annex B, item 25

Statement of Problem and Substantiation for Public Input

Wireless is a more commonly used term. Commercially available products described this way are used for industrial machinery control and status indication. The standard should be consistent with the products used.

Submitter Information Verification

Submitter Full Name: Paul DobrowskyOrganization: Innovative Technology ServicesStreet Address:City:State:Zip:Submittal Date: Wed Jan 06 13:19:38 EST 2016

Committee Statement

Resolution: The term cableless is consistent with IEC 60204-1. Annex A.3.3.14 clarifies all cableless devices asusing wireless technologies while not all wireless devices are cableless.

National Fire Protection Association Report http://submittals.nfpa.org/TerraViewWeb/ContentFetcher?commentPara...

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Revise the standard to make consistent the use of subplate, sub-plate, subpanel, and sub-panel. Ifthese terms are intended to be different, a definition of subpanel is required.


There is ambiguity between the use to subplate and subpanel which would be eliminated by the proposed change.


Submitter Full Name: ROBERT GRUENDELOrganization: DEMATICStreet Address:City:State:Zip:Submittal Date: Fri Dec 25 13:58:59 EST 2015

Committee Statement

Resolution: FR-1-NFPA 79-2016Statement: The term "subpanel" is used only once in the definition of "Industrial Control Panel." Adding the term

"subpanel" in parenthesis to the definition of subplate provides correlation with the use of the term"subpanel" in the definition of "industrial Control Panel". The term "sub-panel" is used only once inAnnex D and does not require any revision as it is used in an example of a bill of materials entry. Theterm sub-plate was not found in the standard.


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Harmonize the use of "clearly visible" and "plainly visible" by eliminating the use of "plainlyvisible". If the use of these terms is intented to denote different degrees of visibility, a definition isneeded for both terms.


The ambiguity of the term clearly visible and plainly visible would be eliminated by the proposed change.


Submitter Full Name: ROBERT GRUENDELOrganization: DEMATICStreet Address:City:State:Zip:Submittal Date: Fri Dec 25 14:08:25 EST 2015

Committee Statement

Resolution: FR-2-NFPA 79-2016Statement: The only instance of “clearly visible” in the standard occurs in 16.2.3.1. Changing “clearly visible” to

“plainly visible” in this clause facilitates consistent use of the term “plainly visible” in the standard.


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Public Input No. 108-NFPA 79-2016 [ Section No. 1.1.1 ]

1.1.1

The provisions of this standard shall apply to the electrical/electronic equipment, apparatus, or systems ofindustrial machines operating from a nominal voltage of 600 volts 1000 volts or less, and commencing atthe point of connection of the supply circuit conductors to the electrical equipment of the machine.


The proposed change aligns with the change in the 2014 NEC where the voltage range for low voltage equipment has been increased to 1000V.


Submitter Full Name: Jay TamblingsonOrganization: Rockwell AutomationStreet Address:City:State:Zip:Submittal Date: Mon Jan 04 14:51:27 EST 2016

Committee Statement

Resolution: FR-3-NFPA 79-2016Statement: The proposed change aligns with the change in the 2014 NEC where the voltage range for low

voltage equipment has been increased to 1000V. Also a TG needs to be formed to review all otherlocations in the document where 600 V limit appears.and determine if a revision is required.

Sections that contain reference to 600 volts are 1.1.1, 3.3.106, 7.2.10.2, 7.9 11.5 and Table 11.5.1.1.


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1.1.1

The provisions of this standard shall apply to the electrical/electronic equipment, apparatus, or systems ofindustrial machines operating from a nominal voltage of 600 volts 1000 volts or less, and commencing atthe point of connection of the supply circuit conductors to the electrical equipment of the machine.


The NEC has changed to 1000 Volts in many locations and making the change in NFPA 79 will be more consistent.



Committee Statement

Resolution: FR-3-NFPA 79-2016Statement: The proposed change aligns with the change in the 2014 NEC where the voltage range for low

voltage equipment has been increased to 1000V. Also a TG needs to be formed to review all otherlocations in the document where 600 V limit appears.and determine if a revision is required.

Sections that contain reference to 600 volts are 1.1.1, 3.3.106, 7.2.10.2, 7.9 11.5 and Table 11.5.1.1.


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Public Input No. 1-NFPA 79-2015 [ Chapter 2 ]

Chapter 2 Referenced Publications

2.1 General.

The documents or portions thereof listed in this chapter are referenced within this standard and shall beconsidered part of the requirements of this document.

2.2 NFPA Publications.

National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471.

NFPA 70® , National Electrical Code®, 2014 edition.

NFPA 70E® , Standard for Electrical Safety in the Workplace®, 2015 edition.

2.3 Other Publications.

2.3.1 ANSI Publications.

American National Standards Institute, Inc., 25 West 43rd Street, 4th Floor, New York, NY 10036.

ANSI Z535.4, Product Safety Signs and Labels, 2007 2011 .

2.3.2 ASTM Publications.

ASTM International, 100 Barr Harbor Drive, P. O. Box C700, West Conshohocken, PA 19428-2959.

ASTM B 8 B8 , Standard Specification for Concentric-Lay–Stranded Copper Conductors, Hard,Medium-Hard, or Soft, 2004 2011 .

ASTM B 174 B174 , Standard Specification for Bunch-Stranded Copper Conductors for ElectricalConductors, 2002 2010, reapproved 2015 .

ASTM B 286 B286 , Standard Specification for Copper Conductors for Use in Hookup Wire for ElectronicEquipment, 2002 2007, reapproved 2012 .

2.3.3 IEC Publications.

International Electrotechnical Commission, 3, rue de Varembé, P.O. Box 131, CH-1211 Geneva 20,Switzerland.

IEC 60072–1, Dimensions and output series for rotating electrical machines — Part 1: Frame numbers 56to 400 and flange numbers 55 to 1080, 1991-03 .

IEC 60072–2, Dimensions and output series for rotating electrical machines — Part 2: Frame numbers 355to 1000 and flange numbers 1180 to 2360, 1990-12 .

2.3.4 IEEE Publications.

IEEE, Three Park Avenue, 17th Floor, New York, NY 10016-5997.

IEEE 315/315A , Graphical Symbols for Electrical and Electronics Diagrams (Including ReferenceDesignation Letters), 1993.

2.3.5 NEMA Publications.

National Electrical Manufacturers Association, 1300 North 17th Street, Suite 1847 900 , RosslynArlington , VA 22209.

NEMA ICS 2, Industrial Control and Systems: Controllers, Contactors, and Overload Relays Rated600 Volts, 2000, Revised 2004 Errara, 2008 .

NEMA MG - 1, Motors and Generators, 2003 2014 .

NEMA 250, Enclosures for Electrical Equipment (1000 Volts Maximum), 2003 2014 .


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2.3.6 UL Publications.

Underwriters Laboratories Inc., 333 Pfingsten Road, Northbrook, IL 60062-2096.

ANSI/UL 50 UL50 , Standard for Enclosures for Electrical Equipment, 2007, revised 2012 .

ANSI/UL 50E UL50E , Standard for Electrical Equipment, Environment Considerations, 2007, revised2012 .

ANSI/UL 508 UL508 , Standard for Industrial Control Equipment, 1999, Revised 2010 2013 .

UL 508A UL508A , Standard for Industrial Control Panels, 2001, Revised 2010 2014 .

ANSI/UL 870 UL870 , Standard for Wireways, Auxiliary Gutters and Associated Fittings, 2008, revised2013 .

ANSI/UL 1063 UL1063 , Standard for Machine-Tool Wires and Cables, 2006, revised 2012 .

ANSI/UL 1581 UL1581 , Reference Standard for Electrical Wires, Cables and Flexible Cords, 2001,Revised 2011 2015 .

2.3.7 U.S. Government Publications.

U.S. Government Printing Government Publishing Office, 732 North Capitol Street, NW, Washington,DC 20402 20401-0001 .

Title 29, Code of Federal Regulations, Part 1910.331–335, “Safety-Related Work Practices.”

2.3.8 Other Publications.

Merriam-Webster’s Collegiate Dictionary, 11th edition, Merriam-Webster, Inc., Springfield, MA, 2003.

2.4 References for Extracts in Mandatory Sections.

NFPA 70® , National Electrical Code®, 2014 edition.

NFPA 70E® , Standard for Electrical Safety in the Workplace®, 2015 edition.


Referenced current SDO names, addresses, standard names, numbers, and editions.

Related Public Inputs for This Document

Related Input RelationshipPublic Input No. 2-NFPA 79-2015 [Chapter K]


Submitter Full Name: Aaron AdamczykOrganization: [ Not Specified ]Street Address:City:State:Zip:Submittal Date: Tue Jun 16 00:34:17 EDT 2015

Committee Statement

Resolution: FR-4-NFPA 79-2016Statement: Referenced current SDO names, addresses, standard names, numbers, and editions.


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Public Input No. 111-NFPA 79-2016 [ New Section after 2.3.2 ]

DOE HANDBOOK -1003

GUIDE TO GOOD PRACTICES FOR TRAINING AND QUALIFICATION OF MAINTENANCEPERSONNEL


This DOE handbook gives guidance to industrial management when qualifying electrical maintenance workers to germane job tasks. It is presently used as a guide to all DOE projects and suggested by OSHA as a guide.


Related Input RelationshipPublic Input No. 112-NFPA 79-2016 [New Section after 3.3.75]


Submitter Full Name: David CarpenterOrganization: City Of Florence AlabamaStreet Address:City:State:Zip:Submittal Date: Tue Jan 05 10:15:07 EST 2016

Committee Statement

Resolution: The proposed text to reference the DOE Handbook in Section 2 is moved to Annex K.2 as a FR- #5.It is intended as an information resource only. Chapter 2 contains referenced publications which areconsidered part of the requirements of the standard.


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2.3.6 UL Publications.

Underwriters Laboratories Inc., 333 Pfingsten Road, Northbrook, IL 60062-2096.

ANSI/UL 50, Standard for Enclosures for Electrical Equipment, 2007. Revised 2015.

ANSI/UL 50E, Standard for Electrical Equipment, Environment Considerations, 2007, Revised 2015 .

ANSI/UL 508, Standard for Industrial Control Equipment, 1999, Revised 2010 2013 .

UL 508A, Standard for Industrial Control Panels, 2001, Revised 2010 2014 .

ANSI/UL 870, Standard for Wireways, Auxiliary Gutters and Associated Fittings, 2008, Revised 2013 .

ANSI/UL 1063, Standard for Machine-Tool Wires and Cables, 2006, Revised 2012 .

ANSI/UL 1581, Reference Standard for Electrical Wires, Cables and Flexible Cords, 2001, Revised2011 2015 .

ANSI/UL 2556 , UL Standard for Safety for Wire and Cable Test Methods , 2015


UL Standards listed have been updated/revised to newer editions.

UL 2556 is the tri-national (US, Canada, Mexico) version of UL 1581. UL 1581 is being revised to move the methods to UL 2556. Rather than referencing one standard which then refers to another standard, having the direct reference is preferred.


Submitter Full Name: Ronald FarrOrganization: Ul LlcStreet Address:City:State:Zip:Submittal Date: Tue Jan 05 13:55:55 EST 2016

Committee Statement

Resolution: There is no reference to UL 2556 in NFPA 79.


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Public Input No. 124-NFPA 79-2016 [ New Section after 3.3 ]

TITLE OF NEW CONTENT Autotransformer

Type your content here ...3.3.X Autotransformer: A type of transformer in which the primary and secondary

coils have part of, or all of their turns in common.


To provide a definition for an single winding transformer (autotransformer).


Submitter Full Name: George SchreckOrganization: Komatsu America Industries, LLStreet Address:City:State:Zip:Submittal Date: Tue Jan 05 16:41:15 EST 2016

Committee Statement

Resolution: Adding a definition of autotransformer would be beneficial. However, the submitter does not identifythe source of the definition. Further, comparing definitions of autotransformer from various sources tothe submitter’s there is a confusion regarding the primary and secondary coils have part of, or all oftheir turns in common.


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3.3.5* Adjustable Speed Drive.

A combination of the power converter, motor, and motor mounted auxiliary devices such as encoders,tachometers, thermal switches and detectors, air blowers, heaters, and vibration sensors.

Power conversion equipment that provides a means of adjusting the speed of an electric motor.

[ 70 :100]


Consider revising this definition as recommended to correlate with the definition in the 2014 NEC.


Submitter Full Name: Mark HilbertOrganization: MR Hilbert Electrical InspectiStreet Address:City:State:Zip:Submittal Date: Thu Jan 07 21:47:57 EST 2016

Committee Statement

Resolution: FR-18Statement: The definition of "adjustable speed drive" is revised to correlate with the definition in the 2014 NEC.

The annex material for A.3.3.5 is revised to add the text of the Informational Note to the definition of"adjustable speed drive" in the 2014 NEC at the end of the existing text of A.3.3.5. The definition of"adjustable speed drive system" in the 2014 NEC is added as a new section in Chapter 3 as this termis being added to Chapter 4.


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3.3.xx Basic protectionprotection against electric shock under fault-free conditions


The IEC terminology “protection against direct contact” has been replaced with “basic protection” in the Ed. 6 of IEC 60204-1 and all other IEC standards. The terminology in NFPA 79 should align where feasible with IEC 60204-1.


Related Input RelationshipPublic Input No. 105-NFPA 79-2016 [New Section after A.3.3.8]Public Input No. 162-NFPA 79-2016 [Chapter 6]



Committee Statement

Resolution: FR-20-NFPA 79-2016Statement: The committee accepts the new definition of “basic protection” but adds the term “protection from

direct contact” in parenthesis for historical reference for one revision cycle for a better understandingof the terms. The committee also accepts the new annex note.


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3.3.13 Cableless Wireless Control.

Control devices employing wireless techniques (e.g., radio, infrared) techniques for transmittingcommands and signals between a machine control system and operator control station(s) that are notconnected by conductors or cables .





Committee Statement

Resolution: “Cableless control” is globally accepted terminology used when using wireless techniques tocommunicate between a machine control system and operator control stations. Changing to “wirelesscontrol” could lead to confusion as wireless technologies can be used for other types of control (forexample, between a control system and field sensors and actuators.). Note: 9.2.7.1 provides adescription of cableless control with essentially the same wording as the definition.


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3.3.14* Cableless Wireless Operator Control Station.

An operator control station that is capable of using wireless techniques (e.g., radio, infrared) techniquesthat are not connected by conductors or cables, to communicate with one or more machines and thatincorporates a self-contained power source, such as a battery.





Committee Statement

Resolution: “Cableless operator control station” is globally accepted terminology used when using wirelesstechniques to communicate between a machine control system and operator control stations.Changing to “wireless control” could lead to confusion as wireless technologies can be used for othertypes of control (for example, between a control system and field sensors and actuators.). Note:9.2.7.1 provides a description of cableless control with essentially the same wording as the definition.


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Public Input No. 193-NFPA 79-2016 [ Section No. 3.3.19.4 ]

3.3.19.4* Liquidtight Flexible Nonmetallic Conduit (LFNC).

A raceway of circular cross section of various types as follows: (1) A smooth seamless inner core and coverbonded together and having one or more reinforcement layers between the core and covers, designated asType LFNC-A; (2) A smooth inner surface with integral reinforcement within the raceway wall, designatedas Type LFNC-B; (3) A corrugated internal and external surface without integral reinforcement within theconduit raceway wall, designated as LFNC-C.

[ 70 :356.2]


Consider revising this definition as recommended to correlate with the definition in the 2014 NEC.



Committee Statement

Resolution: FR-6-NFPA 79-2016Statement: Revised this definition as recommended to correlate with the definition in the 2014 NEC.


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TITLE OF NEW CONTENTType your content here ...

3.3.33 NEW

Add the definition of Effective Ground Fault Current Path to be copied from NEC Article 100

Effective Ground-Fault Current Path. An intentionally constructed, low-impedance electrically conductivepath designed and intended to carry current under ground-fault conditions from the point of a ground faulton a wiring system to the electrical supply source and that facilitates the operation of the overcurrentprotective device or ground-fault detectors.


This term is proposed in Chapter 8 and adding the definition will help users understand the term.



Committee Statement

Resolution: FR-57-NFPA 79-2016Statement: This term was added in Chapter 8 and adding the definition will help users understand the term.


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3.3.40 Exposed (as applied to live energized electrical conductors or circuit parts).

Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is appliedto parts not suitably guarded, isolated, or insulated.

[ 70E :100]


Consider revising this definition as recommended to correlate with the definition in the NFPA 70E.



Committee Statement

Resolution: Revising this definition would create an inconsistent use of terms within NFPA 79. Based on Section1.5 the NEC is the reference document for NFPA 79 is the NEC which uses live parts.


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3.yy* Fault Protectionprotection against electric shock under single-fault conditions


The IEC terminology “protection against indirect contact” has been replaced with “fault protection” in the Ed. 6 of IEC 60204-1 and all IEC standards. The terminology in NFPA 79 should align where feasible with IEC 60204-1.


Related Input RelationshipPublic Input No. 106-NFPA 79-2016 [New Section after A.3.3.42]Public Input No. 162-NFPA 79-2016 [Chapter 6]



Committee Statement

Resolution: FR-22-NFPA 79-2016Statement: The committee accepts the new definition of the term “fault protection” but adds the term “protection

from indirect contact” for historical reference for one revision cycle for a better understanding of theterms. The committee also accepts the new annex note.


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Public Input No. 195-NFPA 79-2016 [ Sections 3.3.64.2, 3.3.64.2 ]

Sections 3.3.64.2, 3.3.64.2

3.3.64.2 Wet Location.

Installations underground or in concrete slabs or masonry in direct contact with the earth; and in locationssubject to saturation with water or other liquids, such as vehicle washing areas; and in unprotectedlocations exposed to weather. [70:100]

3.3.64.2 Wet Location.

Installations underground or in concrete slabs or masonry in direct contact with the earth; and in locationssubject to saturation with water or other liquids, such as vehicle washing areas; and in unprotectedlocations exposed to weather. [70:100]


Revise this definition as recommended to correlate with the definition in the 2014 NEC.



Committee Statement

Resolution: FR-12-NFPA 79-2016Statement: Revise this definition of "wet location" by removing the word "and" and retain the definition of "dry

location" as recommended to correlate with the definitions in the 2014 NEC.


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Fine Print Note:

See DOE HANDBOOK 1003 - " GUIDE TO GOOD PRACTICES FOR TRAINING AND QUALIFICATIONOF MAINTENANCE PERSONNEL" for guidance of qualified persons criteria germane to maintenance jobtasks


Give informational guidance to reconciling qualifications of maintenance workers performing electrical job tasks.


Related Input RelationshipPublic Input No. 111-NFPA 79-2016 [New Section after 2.3.2] clarification and documentation


Submitter Full Name: David CarpenterOrganization: City Of Florence AlabamaStreet Address:City:State:Zip:Submittal Date: Tue Jan 05 10:27:10 EST 2016

Committee Statement

Resolution: An informational reference in Annex K.2 created (FR-5) which eliminates the need for aninformational note


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3.3.91 Socket.

See 3.3.77 , Receptacle.


This is an IEC term and should have been deleted in the 2015 edition.



Committee Statement

Resolution: The term “socket’ is used in multiple locations in the standard. Each use of the term should bereviewed and its deletion considered if the definition is to be deleted.


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Visible.Able to be seen. May require the movement of surrounding equipment or unmounting of equipment to beseen.


The term is used throughout the standard and needs to be defined.


Submitter Full Name: Robert GruendelOrganization: DematicStreet Address:City:State:Zip:Submittal Date: Wed Jan 06 11:34:47 EST 2016

Committee Statement

Resolution: The term “visible” is easily understood and the proposed definition does not add clarity to thestandard. It is the dictionary


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Visible, ClearlyAble to be seen without the movement of surrounding equipment or unmounting of equipment to be seen.


The term clearly (and plainly) visible are used throughout the standard and needs to be defined.


Submitter Full Name: Robert GruendelOrganization: DematicStreet Address:City:State:Zip:Submittal Date: Wed Jan 06 11:40:09 EST 2016

Committee Statement

Resolution: A definition of "clearly visible" is not needed as this term has been removed from the standard by theaction on FR-2.


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Public Input No. 109-NFPA 79-2016 [ Chapter 4 [Title Only] ]

General Operating Conditions Requirements


This change better reflects that the Chapter contains requirements and aligns with the title in IEC 60204-1.



Committee Statement

Resolution: FR-13-NFPA 79-2016Statement: The revised title more accurately reflects the material covered in Chapter 4.


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TITLE OF NEW CONTENTType your content here .4.3.2.8 Control voltage derived from voltage greater than 120vac.

A single winding transformer (autotransformer) shall not be used to convert 120vac control voltage fromgreater voltage supply source (i.e.: load side of Main Disconnect Switch).

Additional Proposed Changes

File Name Description ApprovedTapped_autotransformer.svg.png Autotransformer


Use of autotransformer for control voltage, a short or open in tapped secondary will cause full primary voltage to be applied to control circuit, allowing over-voltage potential to be applied to devices not so rated. Shock and fire hazard potential..


Submitter Full Name: George SchreckOrganization: Komatsu America Industries, LLStreet Address:City:State:Zip:Submittal Date: Tue Jan 05 16:30:37 EST 2016

Committee Statement

Resolution: The standard currently does not allow the use of an autotransformer for control circuits. Thestatement prohibiting the use of autotransformers for control circuits currently exists in Clause 9.1.1.1(Control Circuit Supply). An additional statement in Chapter 4 is considered unnecessary.


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4.3.2.3 Harmonics.

The electrical equipment shall be designed to operate correctly where the harmonic distortion from theelectric supply does not exceed 10 percent 12 percent of the total voltage (rms value) betweenungrounded conductors for the sum of the second through fifth harmonic. An additional 2 percent of thetotal voltage (rms value) between ungrounded conductors for the sum of the sixth through thirtiethharmonic shall be permitted.


This change aligns with changes in Ed. 6 of IEC 60204-1 to correct requirements for expected harmonic levels in an industrial environment.



Committee Statement

Resolution: The proposed text does not align with proposed changes in IEC 60204-1 Ed. 6. In addition, there isno technical reference to the origin of the new harmonic levels and no substantiation is provided forwhy they should be increased.


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4.4.2* Electromagnetic Compatibility (EMC).

Transient suppression, isolation, or other appropriate means shall be provided where the equipment of anindustrial machine generates electrical noise or transients, which can affect the operation ofequipment that industrial machine .


The wording has been confusing due to the use of the term "the" describing the noise generating equipment but no term used to describe which equipment could be affected. The owner or their designer needs to address what type of equipment needs to be separated from other types of equipment that are not part of the same industrial machine.



Committee Statement

Resolution: FR-14-NFPA 79-2016Statement: The proposed revision restricts the requirement for inclusion of noise suppression techniques to only

prevent adverse conditions to the machine producing or receiving the noise itself. The effects onother equipment within the surrounding area must be considered but the machine is not required tohave noise suppression for other such equipment.


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Public Input No. 101-NFPA 79-2016 [ Section No. 4.8 ]

4.8 Available Fault Current.

The available fault current at the point(s) of the supply to the each industrial control panel of a machineshall not be greater than the short-circuit current rating marked on the industrial control panel nameplate.


The revised text provides clarification for machines with more than one source of supply and/or control panel.


Submitter Full Name: Jay TamblingsonOrganization: Rockwell AutomationStreet Address:City:State:Zip:Submittal Date: Sun Jan 03 15:38:08 EST 2016

Committee Statement

Resolution: FR-15-NFPA 79-2016Statement: The revised text provides clarification for machines with more than one source of supply and/or

control panels. The committee agrees with the submitted substantiation as it is current practice wheremore than one source of supply is present.


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Public Input No. 130-NFPA 79-2016 [ Chapter 5 [Title Only] ]

Incoming Chapter 5 Supply Circuit Conductor Terminations and Devices for Disconnecting Meansand Removing Power Terminations


The title of Chapter 5 is excessively long and does not very well describe the Chapter. The term supply circuit includes the concept of being "incoming" and the term "disconnecting means" includes the concept of "removing power".


Submitter Full Name: Paul DobrowskyOrganization: Innovative Technology ServicesStreet Address:City:State:Zip:Submittal Date: Tue Jan 05 21:02:10 EST 2016

Committee Statement

Resolution: FR-25-NFPA 79-2016Statement: The title of Chapter 5 is excessively long and does not very well describe the Chapter. The term

supply circuit includes the concept of being "incoming" and the term "disconnecting means" includesthe concept of "removing power".


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5.1.6

Each set of incoming supply circuit conductors on the line side of the disconnecting means shall beseparated from all other internal conductors, including conductors of other supply circuits by either of thefollowing:

(1) Mounting the supply circuit disconnect as near as practicable to the top of the enclosure withdedicated wire bending space as in 5.1.5

(2) Mounting the supply circuit disconnect other than at the top of the enclosure and by separating thesupply circuit conductors from other internal conductors by the use of a barrier. Devices, terminalblock assemblies, device mounting brackets or plates, do not constitue a barrier.


Many items can be used to create a "barrier." Definitions of barrier (in 79 and 70E) do not specify what constitutes a "barrier" -- size, material, etc. Emphasis is not given to (1). JIC E3.9.3 was specific: The disconnecting means shall be mounted at the top of the control panel with no other equipment mounted directly above it. When dealing with "foreign" users who are translating into their own language, vagueness can and does lead to miss interpretation and hence, implementation.


Submitter Full Name: George SchreckOrganization: Komatsu America Industries, LLStreet Address:City:State:Zip:Submittal Date: Thu Jan 07 14:30:29 EST 2016

Committee Statement

Resolution: The definition of “barrier” is located in chapter 3. Revising or explaining the definition at each locationwhere the term is used does not add clarity or understanding to the term. Some of the items includedin the proposed additional sentence such as "plates" could be used as a barrier. This section isaddressing separation of the conductors, not the terminations or device mounting brackets.


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Public Input No. 187-NFPA 79-2016 [ Section No. 5.3 ]

5.3 Supply Incoming supply Circuit Disconnecting (Isolating) Means.

5.3.1 General.

The following general requirements apply to 5.3.2 through 5.3.5.

5.3.1.1

A supply An incoming supply circuit disconnecting means shall be provided for the following:

(1) Each incoming supply circuit to a machine

(2) The incoming supply circuit to a feeder system using collector wires, collector bars, slip-ringassemblies, or flexible cable systems (reeled, festooned) to a machine or a number of machines

(3) Each on-board power source (e.g., generators, uninterruptible power supplies)

Exception: Communication, remote control, and signaling circuits of less than 50 volts shall not berequired to be provided with a supply circuit disconnecting means.

5.3.1.1.1 *

Each disconnecting means required by 5.3.1.1 shall be legibly marked to indicate the equipment itdisconnects.

5.3.1.1.2

Where a machine is supplied by more than one incoming supply circuit, a marking shall be installed ateach incoming supply circuit disconnect location denoting the location of all other incoming supply circuitdisconnects.

5.3.1.2

The incoming supply circuit disconnecting means shall disconnect (isolate) the electrical equipment of themachine, including all control circuits, from the incoming supply circuit when required (e.g., for work on themachine, including the electrical equipment). Circuits that are not required to be disconnected by theincoming supply circuit disconnecting means shall comply with 5.3.5.

5.3.1.3

Each incoming supply circuit disconnecting means other than attachment plugs and receptacles shall bemounted within the control enclosure or immediately adjacent thereto.

Exception No. 1: Externally mounted incoming supply circuit disconnecting means, whether interlocked ornot interlocked with the control enclosure, supplying machines totaling 2 hp or less shall be permitted tobe mounted up to 6 m (20 ft) away from the enclosure,provided the disconnecting means is in sight fromand readily accessible to the operator.

Exception No. 2: A supply An incoming supply circuit disconnecting means mounted in a separateenclosure and interlocked in accordance with 6.2.4 with the control enclosure(s) it supplies shall bepermitted to be mounted up to 6 m (20 ft) away,provided the disconnecting means is in sight from thecontrol enclosure(s) and readily accessible to the operator. The control enclosure(s) shall be markedindicating the location of the disconnecting means. The disconnecting means shall be marked indicatingthe industrial machine it supplies.

5.3.1.4

Each incoming supply circuit disconnecting means mounted within or adjacent to the control enclosureshall be interlocked with the control enclosure in accordance with 6.2.4.

Exception: Where a supply an incoming supply circuit disconnecting means, supplying machines totaling2 hp or less is not located within or adjacent to the control enclosure it supplies, the control enclosureshall comply with 6.2.4 or 6.2.5. Where a incoming supply circuit disconnecting means is an attachmentplug and receptacle, the control enclosure it supplies shall comply with 6.2.5. Where 6.2.5 is used, asafety sign shall be provided in accordance with Section16.2.


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5.3.1.5

Where two or more disconnecting means are provided within the control enclosure for multiple supplycircuits, they shall be grouped in one location where practicable. Protective interlocks for their correctoperation shall be provided where a hazardous condition or damage to the machine or to the work inprogress can occur.

5.3.2 Type.

The incoming supply circuit disconnecting device shall be one of the following types:

(1) A listed motor circuit switch (switch disconnector) rated in horsepower

(2) A listed molded case circuit breaker

(3) A listed molded case switch

(4) An instantaneous trip circuit breaker that is part of a listed combination motor controller

(5) A listed self-protected combination controller limited to single motor applications

(6) An attachment plug and receptacle (plug/socket combination) for cord connection

5.3.3 Requirements.

5.3.3.1 *

Where the incoming supply circuit disconnecting device is one of the types in 5.3.2 (1) through 5.3.2 (5),the device shall fulfill all of the following requirements:

(1) Isolate the electrical equipment from the supply circuit and have one off (open) and one on (closed)position only. Circuit breakers, molded-case switches, and self-protected combination motorcontrollers are permitted to have a reset (tripped) position between off (open) and on (closed).

(2) Have an external operating means (e.g., handle) that complies with 5.3.4.

Exception: Power-operated switchgear need not be operable from outside the enclosure where thereare other means to open it.

(3) Be provided with a permanent means permitting it to be locked in the off (open) position only (e.g., bypadlocks), independent of the door position. When so locked, remote as well as local closing shall beprevented.

(4) Simultaneously disconnect all ungrounded conductors of the incoming power supply circuit.

(5) Be operable, by qualified persons, independent of the door position without the use of accessory toolsor devices.

(6) Be rated for the application as follows:

(7) The ampere rating shall be at least 115 percent of the sum of the full-load currents required forall equipment that is in operation at the same time under normal conditions of use.

(8) Where rated in horsepower, the horsepower rating shall be at least equal to that which isdefined by Table 430.251(B) of NFPA 70 , for a locked rotor current equal to the largest sumresulting from the locked rotor currents of any combination of motors that can be startedsimultaneously and the full-load currents of the remaining motor and non-motor loads that canbe operated at that time.

(9) The voltage rating shall be at least equal to the nominal supply circuit voltage.

(10) The disconnecting means shall plainly indicate whether it is in the open (off) or closed position.


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5.3.3.2 *

When the incoming supply circuit disconnecting device is an attachment plug and receptacle (plug/socketcombination), it shall fulfill all of the following requirements:

(1) Have a load-break rating or be interlocked with a switching device that is load-break rated andcomplies with 5.3.3.1(6). An attachment plug and receptacle (plug/socket combination) rated greaterthan 20 amperes or 2 hp shall be listed as a switch-rated plug and receptacle (plug/socketcombination).

(2) Be of such a type and be so installed as to prevent unintended contact with live parts at any time,even during insertion or removal of the connectors.

(3) Have a first-make, last-break electrical grounding contact.

(4) Have a retaining means to prevent unintended or accidental disconnection where rated at more than20 amperes.

(5) Be located within sight from the operator station and be readily accessible.

5.3.3.3

In addition to the requirements in 5.3.3.2, an additional switching device on the machine shall be providedfor routine power switching operations of the machine on and off.

5.3.4 Operating Handle.

5.3.4.1

The center of the grip of the operating handle of the disconnecting means, when in its highest position, shallbe not more than 2.0 m (6 ft 7 in.) above the servicing level. A permanent operating platform, readilyaccessible by means of a permanent stair or ladder, shall be considered the servicing level for the purposeof this requirement.

5.3.4.2

An operating handle of the disconnecting means required by 5.3.3.1 shall meet the following criteria:

(1) Be readily accessible with doors in the open or closed position

(2) Maintain the environmental rating of the enclosure to the degree necessary for the application wheninstalled through the control enclosure

(3) Not be restricted by the enclosure door when the door is in the open position

5.3.5 Excepted Circuits.

5.3.5.1

The following circuits shall not be required to be disconnected by the main incoming supply circuitdisconnecting means:

(1) Lighting circuits for lighting needed during maintenance or repair

(2) Attachment plugs and receptacles (plug and socket outlets) for the exclusive connection of repair ormaintenance tools and equipment (e.g., hand drills, test equipment)

(3) Undervoltage protection circuits that are only used for automatic tripping in the event of supply circuitfailure

(4) Circuits supplying equipment that are required to remain energized for satisfactory operation [e.g.,temperature-controlled measuring devices, product (work in progress) heaters, program storagedevices, inputs, non-motion outputs and displays ]


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5.3.5.2

The incoming supply circuits for excepted circuits shall be provided with all of the following:

(1) A disconnecting means, isolating transformer, and overcurrent protection mounted in an enclosureadjacent to the main control enclosure or within the control enclosure, adjacent to the main supplycircuit disconnecting means.

(2) Line side (of the incoming supply circuit disconnect) input supply circuit conductors, when internal tothe control enclosure, that are separate from and do not share a raceway with other conductors andthat are encased in rigid or flexible conduit if longer than 460 mm (18 in.)

5.3.5.3

The control interlocking circuits shall be capable of being disconnected at the control panel from which theyare sourced.

5.3.5.4

Where the excepted circuits are not disconnected by the incoming supply circuit disconnecting means, allof the following requirements shall be met:

(1) Permanent safety sign(s), shall be placed adjacent to the incoming supply circuit disconnectingoperating handle(s), indicating that it does not de-energize all exposed live parts when it is in the open(off) (isolated) position as in 16.2.4.

(2) A statement containing the information from 16.2.4 shall be included in the machine documentation.

(3) A permanent safety sign shall be placed on a nonremovable part inside the control enclosure inproximity to each excepted circuit, or shall be identified by color as defined in 13.2.4.


Editorial revisions for consistence - added "incoming" in multiple locations. Also added text to correlate with PI 175.

Additionally, I request the panel to consider how to differentiate between the requirements for the main incoming supply circuits/disconnects and downstream control enclosures supplied from the main control enclosure. Perhaps a task group can be created before the FR Meeting to address this issue.


Related Input RelationshipPublic Input No. 175-NFPA 79-2016 [Section No. 9.1.1.4]


Submitter Full Name: Daniel NeeserOrganization: Eaton’s Bussmann DivisionStreet Address:City:State:Zip:Submittal Date: Thu Jan 07 16:35:37 EST 2016

Committee Statement

Resolution: FR-24-NFPA 79-2016Statement: The terms “incoming” and “supply” are redundant. “Supply” is the more common of the two and is

maintained for consistency with the remainder of the standard.

5.3.1.1.1. If a single main disconnecting means is provided on the supply side of multiple


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disconnecting means it needs to be marked to describe its purpose to differentiate it from the otherdisconnecting means, so that it can be operated to de-energize all supply conductors. The additionalrequirement would apply only if a single main is provided and only adds a marking requirement. Thelanguage in Annex A indicates that it is necessary but that is not enforceable.

5.3.1.3 reformatted for readability. The reference to the disconnect to be readily accessible to theoperator in Exception No. 1 has been removed because the operator has access to an emergencystop and operating the disconnect during normal operation could create a safety concern.

5.3.1.4 New exception is added that provides another option that meets an equivalent control as theexisting requirement.

Language added to 5.3.2 (4) to correlate with (5).

Language added to 5.3.3.1 (1) to correlate with 5.3.2 and because the generic term “circuit breaker”implies inverse time and some users have taken this to mean that instantaneous trip circuit breakersare not included.

5.3.5.1 Item (4) is revised to correlate with other rules such as the exception to 9.1.1.4.

5.3.3.1 Stating that the disconnect must be interlocked with the door limits the requirement toenclosures utilizing doors. New technology equipment is utilizing removable covers (not hingeddoors) so clarifying this requirement includes both doors and covers improves the intended safetyafforded by this required interlocking.


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Public Input No. 134-NFPA 79-2016 [ Section No. 5.3.1.1.1 ]

5.3.1.1.1*

Each disconnecting means required by 5.3.1.1 shall be legibly marked to indicate the equipment itdisconnects. A main disconnecting means shall be marked as main if multiple disconnecting means aresupplied from the main disconnecting means.


If multiple disconnecting means are provided on the load side of a main the main needs to be marked as such. This needs to be a rule rather than a vague explanatory statement in Annex A.



Committee Statement



5.3.1.1.1. If a single main disconnecting means is provided on the supply side of multipledisconnecting means it needs to be marked to describe its purpose to differentiate it from the otherdisconnecting means, so that it can be operated to de-energize all supply conductors. The additionalrequirement would apply only if a single main is provided and only adds a marking requirement. Thelanguage in Annex A indicates that it is necessary but that is not enforceable.






5.3.3.1 Stating that the disconnect must be interlocked with the door limits the requirement toenclosures utilizing doors. New technology equipment is utilizing removable covers (not hingeddoors) so clarifying this requirement includes both doors and covers improves the intended safety


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afforded by this required interlocking.


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5.3.1.3

Each supply circuit disconnecting means other than attachment plugs and receptacles shall be mountedwithin the control enclosure or immediately adjacent thereto.

Exception No. 1: Externally mounted supply circuit disconnecting means, whether interlocked or notinterlocked with the control enclosure, supplying machines totaling 2 hp or less shall be permitted to bemounted up to 6 m (20 ft) away from the enclosure,provided the disconnecting means is in sight from andreadily accessible to the operator. the control enclosure(s) and is readily accessible. The controlenclosure(s) shall be marked to indicate the location of the disconnecting means. The disconnectingmeans shall be marked to indicate the machine supplied.

Exception No. 2: A supply circuit disconnecting means mounted in a separate enclosure and interlockedin accordance with 6.2.4 with the control enclosure(s) it supplies shall be permitted to be mounted up to6 m (20 ft) away,provided the disconnecting means is in sight from the control enclosure(s) and is readilyaccessible to the operator . The control enclosure(s) shall be marked indicating to indicate the locationof the disconnecting means. The disconnecting means shall be marked indicating to indicate theindustrial machine it supplies supplied .


Revise the exceptions for consistency in application and terminology and to make it clear the disconnecting means must be readily accessible in all cases not just to the operator. Additionally the term “operator” was removed as is not defined in NFPA 79 and therefore can have different interpretations.

The main rule is to have a disconnecting means within or immediately adjacent to the control enclosure. Therefore, the “within sight from” requirement should be from the control enclosure it supplies not from the operator whom may not be stationed at the control enclosure. Revising Exception No. in this manner will also provide consistency with Exception No. 2 which requires the disconnecting means to be within sight of the control enclosure.

The word "industrial" was removed from in front of "machine in Exception No. 2 for consistency as it is not used that way anywhere else in this section. The entire Standard applies to industrial machines so it is not necessary here.



Committee Statement



5.3.1.1.1. If a single main disconnecting means is provided on the supply side of multiple


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disconnecting means it needs to be marked to describe its purpose to differentiate it from the otherdisconnecting means, so that it can be operated to de-energize all supply conductors. The additionalrequirement would apply only if a single main is provided and only adds a marking requirement. Thelanguage in Annex A indicates that it is necessary but that is not enforceable.








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5.3.3.1 *

Where the supply circuit disconnecting device is one of the types in 5.3.2 (1) through 5.3.2 (5), the deviceshall fulfill all of the following requirements:

(1) Isolate the electrical equipment from the supply circuit and have one off (open) and one on (closed)position only. Circuit breakers, molded-case switches, and self-protected combination motorcontrollers are permitted to have a reset (tripped) position between off (open) and on (closed).

(2) Have an external operating means (e.g., handle) that complies with 5.3.4.

Exception: Power-operated switchgear need not be operable from outside the enclosure where thereare other means to open it.

(3) Be provided with a permanent means permitting it to be locked in the off (open) position only (e.g., bypadlocks), independent of the door or cover position. When so locked, remote as well as local closingshall be prevented.

(4) Simultaneously disconnect all ungrounded conductors of the power supply circuit.

(5) Be operable, by qualified persons, independent of the door or cover position without the use ofaccessory tools or devices.

(6) Be rated for the application as follows:

(7) The ampere rating shall be at least 115 percent of the sum of the full-load currents required forall equipment that is in operation at the same time under normal conditions of use.

(8) Where rated in horsepower, the horsepower rating shall be at least equal to that which isdefined by Table 430.251(B) of NFPA 70 , for a locked rotor current equal to the largest sumresulting from the locked rotor currents of any combination of motors that can be startedsimultaneously and the full-load currents of the remaining motor and non-motor loads that canbe operated at that time.

(9) The voltage rating shall be at least equal to the nominal supply circuit voltage.

(10) The disconnecting means shall plainly indicate whether it is in the open (off) or closed position.


Stating that the disconnect must be interlocked with the door limits the requirement to enclosures utilizing doors. New technology equipment is utilizing removable covers (not hinged doors) so clarifying this requirement includes both doors and covers improves the intended safety afforded by this required interlocking.


Submitter Full Name: Barry BoggsOrganization: Toyota Motor Engineering & ManAffilliation: ToyotaStreet Address:City:State:Zip:Submittal Date: Thu Jan 07 16:36:26 EST 2016

Committee Statement


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5.3.1.1.1. If a single main disconnecting means is provided on the supply side of multipledisconnecting means it needs to be marked to describe its purpose to differentiate it from the otherdisconnecting means, so that it can be operated to de-energize all supply conductors. The additionalrequirement would apply only if a single main is provided and only adds a marking requirement. Thelanguage in Annex A indicates that it is necessary but that is not enforceable.








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5.5.1

Devices shall be provided for disconnecting (isolating) electrical equipment to enable work to be performedwhen it is de-energized and isolated.

Revise to:

5.5.1 Electrical equipment shall be provided a means of disconnecting (isolating) which establishes anelectrically safe work condition.


Current statement is somewhat vague with the use of the pronoun "IT". Disconnecting Means, or the equipment. NFPA 79, 5.5.1 - is limited in scope to only De-energized and Isolated - neither of which are defined in Chapter 3.

However, NFPA 70E Article 120 uses the term "Establishing an Electrically Safe Work Condition" - which is also defined in Article 100 - "Electrically Safe Work Condition" - " A state in which an electrical conductor or circuit part has been disconnected from energized parts, locked/tagged in accordance with established standards, tested to ensure the absence of voltage, and grounded if determined necessary."


Submitter Full Name: Earl SowdersOrganization: Toyota EngineeringStreet Address:City:State:Zip:Submittal Date: Tue Dec 15 15:04:05 EST 2015

Committee Statement

Resolution: The disconnecting (isolating) means does not create an electrically safe working condition. Creatingan electrically safe working condition is a process that includes additional steps beyond just operatingand locking or tagging a disconnecting means. (See 120.1 of NFPA 70E).


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Public Input No. 162-NFPA 79-2016 [ Chapter 6 ]

Chapter 6 Protection from Electrical Hazards

6.1 * General.

Electrical equipment shall provide protection of persons from electric shock , from direct and indirectcontact by basic protection (see 6.2 and 6.4) and fault protection (see 6.3 and 6.4) , and warn of potentialarc-flash hazards (see 6 .6).

6.2 * Basic Protection Against Direct Contact.

Live parts

.

6.2.1 General.

For each circuit and part of the electrical equipment operating at 50 volts rms ac or 60 volts dc or moreshall be guarded against contact , the basic protection (see 3.3.xx) requirements of 6.2.2 or 6.2.3 shall beapplied .

6.2. 1 2 Protection by Insulation of Live Parts.

Live parts protected by insulation shall be completely covered with insulation that can only be removed bydestruction. Such insulation shall be capable of withstanding the mechanical, chemical, electrical, andthermal stresses to which the insulation is subjected under normal operating conditions. Paints, varnishes,lacquers, and similar products shall not be considered protection against electric shock under normaloperating conditions.

6.2. 2 Protection 3 Protection by Enclosures .

6.2.3 Direct Contact from Outside an Enclosure.

Equipment enclosures and enclosure openings shall meet the requirements of ANSI/UL 508, UL 508A,ANSI/UL 50, or NEMA 250. (See Figure 6.2.3.)

Figure 6.2.3 Jointed Test Finger.

Exception: In the absence of a rated enclosure, the determination of the suitability of an enclosure asprotection from electrical shock shall be determined by using a test finger as described in Figure 6.2.3.The test finger shall be applied, with only minimal force, in every opening in the enclosure after removal ofall parts of the enclosure that are capable of being removed without the use of a tool. The test finger shallnot encounter live parts in any direction.


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6.2. 4 3.1 Enclosure Interlocking.

When required by 5.3.1.4, each disconnecting means mounted within or adjacent to a control enclosurethat contains live parts operating at 50 volts ac (rms value) or 60 volts dc or more shall be mechanically orelectrically interlocked, or both, with the control enclosure doors so that none of the doors open unless thepower is disconnected. Interlocking shall be reactivated automatically when all the doors are closed.

Exception No. 1: A disconnecting means used only for maintenance lighting circuits within controlenclosures shall not be required to be interlocked with the control enclosure. A safety sign shall beprovided that meets the requirements of 16.2.4.

Exception No. 2: A disconnecting means used for power supply circuits within control enclosures tomemory elements and their support logic requiring power at all times to maintain information storageshall not be required to be interlocked with the control enclosure doors. A safety sign shall be providedthat meets the requirements of 16.2.4.

6.2. 4 3 .1 .1 *

Means shall be permitted to be provided for qualified persons, using appropriate work practices, to gainaccess without removing power.

6.2. 4 3 . 1. 2

The interlocking means shall meet the following requirements:

(1) Utilize a device or tool as specified by the manufacturer of the interlock to allow qualified persons todefeat the interlock

(2) Be reactivated automatically when the door(s) is closed

(3) Prevent closing of the disconnecting means while the door of the enclosure containing the disconnectis open, unless an interlock is operated by deliberate action

6.2. 4 3 . 1. 3

Where provided with a defeat mechanism as permitted in 6.2.4 3 .1. 2 (1), live parts mounted on the insideof doors that are operating at over 50 volts shall be protected from unintentional direct contact by theinherent design of components or the application of barriers or obstacles such that a 50 mm (2 in.) spherecannot contact any of the live parts in question.

6.2. 5 3.2 Enclosure Access.

When a qualified person, using appropriate work practices, needs to enter an enclosure that does not havea disconnect, one of the following conditions shall be met:

(1) The use of a key or tool shall be required for opening the enclosure.

(2) An enclosure door shall be permitted to be opened without the use of a key or a tool and withoutdisconnection of live parts only when all live parts inside are separately enclosed or guarded such thatthere cannot be any direct contact with live parts.

6.3 Protection Against Electric Shock from Indirect Contact (Fault Conditions) Fault Protection .

6.3.1 General * General .


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Protection against indirect contact

Fault protection (see 3.3.

20.2

yy ) is intended to prevent hazardous

conditions to continue in the event of a fault condition (e.g., insulation failure between

situations due to an insulation fault between live and exposed conductive parts

).

6.3.1.1 * Protection Against Indirect Contact.

Protection against indirect contact shall be achieved by the following

.

For each circuit part or part of the electrical equipment, at least one of the following measures shall beapplied :

(1) Measures to prevent the occurrence of a hazardous touch voltage by means of double insulation (see6.3.1. 2), or

(2) Automatic disconnection of the supply (interruption of one or more of the ungrounded conductorsaffected by the automatic operation of a protective device in case of a fault) (see 6.3.1. 3).

6.3. 1. 2 Protection by Double Insulation.

Measures to prevent the occurrence of a hazardous touch voltage by means of double insulation shall beas follows:

(1) Protection by use of double insulation is intended to prevent the occurrence of hazardous touchvoltages on the accessible parts through a failure in the basic insulation.

(2) When this means is used to prevent a hazardous touch voltage, the equipment shall be listed to beprotected by a system of double insulation, or its equivalent. Where such a system is employed, theequipment shall be distinctively marked.

6.3. 1. 3 Protection by Automatic Disconnection of Supply.

Automatic disconnection of the supply of any circuit affected by the particular circuit overcurrent protectivedevice in the event of a fault is intended to prevent an exposure to a continuous hazardous touch voltage.These protective measures comprise both of the following:

(1) Protective bonding of exposed conductive parts (see 8.2.3)

(2) The use of overcurrent protection devices for the automatic disconnection of the supply in the event ofa fault

6.4 Protection by the Use of Protective Extra Low Voltage (PELV).

6.4.1 General Requirements.

The use of PELV, as described in Section 6.4, is to protect persons against electric shock from indirectcontact and limited area direct contact.


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6.4.2

PELV circuits shall satisfy all of the following conditions:

(1) The nominal voltage shall not exceed the following:

(2) 30 volts ac (rms value) or 60 volts dc (ripple-free) when the equipment is used in normally drylocations and when large area contact of live parts with the human body is not expected

(3) 6 volts ac (rms value) or 15 volts dc (ripple-free) in all other cases

(4) One side of the circuit or one point of the source of the supply of that circuit shall be connected to theequipment grounding circuit.

(5) Live parts of PELV circuits shall be electrically separated from other live circuits. Electrical separationshall be not less than that required between the primary and secondary circuits of a safety isolatingtransformer.

(6) Conductors of each PELV circuit shall be physically separated from those of any other circuit. Whenthis requirement is impracticable, the insulation provisions of 13.1.3 shall apply.

(7) Attachment plugs and receptacles (plugs and socket combinations) for a PELV circuit shall conform tothe following:

(8) Attachment plugs (plugs) shall not be able to enter receptacles (socket-outlets) of other voltagesystems.

(9) Receptacles (socket-outlets) shall not admit plugs of other voltage systems.

6.4.3 Sources for PELV.

The source for PELV shall be one of the following:

(1) A safety isolating transformer

(2) A source of current providing a degree of safety equivalent to that of the safety isolating transformer(e.g., a motor generator with winding providing equivalent isolation)

(3) An electrochemical source (e.g., a battery) or another source independent of a higher voltage circuit(e.g., a diesel-driven generator)

(4) An identified electronic power supply conforming to standards specifying measures to be taken toensure that, even in the case of an internal fault, the voltage at the outgoing terminals does notexceed the values specified in 6.4.2 (1)

6.5 Protection Against Residual Voltages.

6.5.1

Live parts having a residual voltage greater than 60 volts after the supply has been disconnected shall bereduced to 60 volts or less within 5 seconds after disconnection of the supply voltage.

Exception No. 1: Exempted from this requirement are components having a stored charge of60 microcoulombs or less.

Exception No. 2: Where such a provision would interfere with the functioning of the equipment, a durablesafety sign drawing attention to the hazard and stating the delay required before entry to the enclosure isallowed shall be displayed at an easily visible location on or immediately adjacent to the enclosurecontaining the capacitance.

6.5.2

The withdrawal of plugs or similar devices, which results in the exposure of conductors (e.g., pins), shallhave a discharge time that does not exceed 1 second.

Exception No. 1: Exempted from this requirement are components having a stored charge of60 microcoulombs or less.

Exception No. 2: Exempted from this requirement are conductors that are protected against directcontact.

6.5.3 Discharge of Stored Energy.


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Capacitors shall be provided with a means of discharging stored energy. [70:460.6]

6.5.3.1 Time of Discharge.

The residual voltage of a capacitor shall be reduced to 50 volts, nominal, or less, within 1 minute after thecapacitor is disconnected from the source of supply. [70:460.6(A)]

6.5.3.2 Means of Discharge.

The discharge circuit shall be either permanently connected to the terminals of the capacitor or capacitorbank, or provided with automatic means of connecting it to the terminals of the capacitor bank on removalof voltage from the line. Manual means of switching or connecting the discharge circuit shall not be used.[70:460.6(B)]

6.6 Arc Flash Hazard Warning.

A safety sign shall be provided in accordance with 16.2.3.

Additional Proposed Changes

File Name Description ApprovedChapter_6_PI162_.docx PI162 with edits shown correctly


NOTE: The online editing system may not be correctly showing the proposed changes. Please see attached document with highlighted edits for proper review of this public input.

The IEC terminology “protection against direct contact” has been replaced with “basic protection” and the term “protection against indirectcontact” has been replaced with “fault protection”. The revised language aligns NFPA 79 with similar language in Ed. 6 of IEC 60204-1. Inaddition, some of the sections were renumbered to correct a numbering issue with 6.2.2 in the 2015 edition and to group the enclosure relatedclauses together.


Related Input RelationshipPublic Input No. 103-NFPA 79-2016 [New Section after 3.3.42]Public Input No. 104-NFPA 79-2016 [New Section after 3.3.8]Public Input No. 184-NFPA 79-2016 [Section No. A.6.2]Public Input No. 185-NFPA 79-2016 [Section No. A.6.2.4.1]Public Input No. 186-NFPA 79-2016 [Section No. A.6.3.1.1]


Submitter Full Name: Jay TamblingsonOrganization: Rockwell AutomationStreet Address:City:State:Zip:Submittal Date: Thu Jan 07 13:49:22 EST 2016

Committee Statement

Resolution: FR-28-NFPA 79-2016


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Statement: To maintain consistency with IEC 60204-1 and other IEC standards, the section is revised to use theterms “Basic Protection” and “Fault Protection” as they are not in conflict with NEC terms. The IECterminology “protection against direct contact” has been replaced with “basic protection” and the term“protection against indirect contact” has been replaced with “fault protection”. The revised languagealigns NFPA 79 with similar language in Ed. 6 of IEC 60204-1.The revised text retains the use of theterm “Live parts” in section 6.2.1 for consistency within NFPA 79 and the NEC.

Renumbering of 6.1 – 6.3 was done to correct editorial errors and group "enclosure" relatedrequirements together.

The phrase “and warn of potential arc-flash hazards” was removed because Chapter 16 contains therequirements for markings and signs.

Figure 6.2.3 was retained as normative requirements cannot be located in an informative annex.

Class 2 circuits have a long history of acceptable use without additional shock barriers in the NECand now specifically addressed in NFPA 79. There is no reason they should not be allowed to beused for industrial machinery as protection from shock.

Annex

Deleting A.6.2--Voltage levels permitted in other countries may vary from those indicated.

Moving A.6.2.4.1 to A.6.2.3.1.1--PI162 moved reference section.

Moving A.6.3.1.1 to A.6.3.1--PI162 moved reference section.


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This data is the property of Schenck Process, LLC. The infonnation contained hereon is to be treated in confidence and is not to be used directly or indirectly in any way detrimental to our interests.

Chapter 6 Protection from Electrical Hazards 6.1* General. Electrical equipment shall provide protection of persons from electric shock, by basic protection (see 6.2 and 6.4) and fault protection (see 6.3 and 6.4) from direct and indirect contact, and warn of potential arc-flash hazards.

6.2* Basic Protection Against Direct Contact. 6.2.1 General

For each circuit and part of the electrical equipment Live parts operating at 50 volts rms ac or 60 volts dc or more, the basic protection (see 3.3.xx) requirements of 6.2.2 or 6.2.3 shall be applied. shall be guarded against contact.

6.2.21 Protection by Insulation of Live Parts. Live parts protected by insulation shall be completely covered with insulation that can only be removed by destruction. Such insulation shall be capable of withstanding the mechanical, chemical, electrical, and thermal stresses to which the insulation is subjected under normal operating conditions. Paints, varnishes, lacquers, and similar products shall not be considered protection against electric shock under normal operating conditions.

6.2.2 Protection by Enclosures. 6.2.3 Protection by Enclosures. Direct Contact from Outside an Enclosure. Equipment enclosures and enclosure openings shall meet the requirements of ANSI/UL 508, UL 508A, ANSI/UL 50, or NEMA 250. (See Figure 6.2.3.)

Figure 6.2.3 Jointed Test Finger.

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Exception: In the absence of a rated enclosure, the determination of the suitability of an enclosure as protection from electrical shock shall be determined by using a test finger as described in Figure 6.2.3. The test finger shall be applied, with only minimal force, in every opening in the enclosure after removal of all parts of the enclosure that are capable of being removed without the use of a tool. The test finger shall not encounter live parts in any direction. 6.2.3.1 4 Enclosure Interlocking. When required by 5.3.1.4, each disconnecting means mounted within or adjacent to a control enclosure that contains live parts operating at 50 volts ac (rms value) or 60 volts dc or more shall be mechanically or electrically interlocked, or both, with the control enclosure doors so that none of the doors open unless the power is disconnected. Interlocking shall be reactivated automatically when all the doors are closed.

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Exception No. 1: A disconnecting means used only for maintenance lighting circuits within control enclosures shall not be required to be interlocked with the control enclosure. A safety sign shall be provided that meets the requirements of 16.2.4. Exception No. 2: A disconnecting means used for power supply circuits within control enclosures to memory elements and their support logic requiring power at all times to maintain information storage shall not be required to be interlocked with the control enclosure doors. A safety sign shall be provided that meets the requirements of 16.2.4. 6.2.3.1.1 4.1* Means shall be permitted to be provided for qualified persons, using appropriate work practices, to gain access without removing power.

6.2.3.1.2 4.2 The interlocking means shall meet the following requirements:

1) Utilize a device or tool as specified by the manufacturer of the interlock to allow qualified persons to defeat the interlock

2) Be reactivated automatically when the door(s) is closed

3) Prevent closing of the disconnecting means while the door of the enclosure containing the disconnect is open, unless an interlock is operated by deliberate action

6.2.3.1.3 4.3 Where provided with a defeat mechanism as permitted in 6.2.3.1.2 4.2 (1), live parts mounted on the inside of doors that are operating at over 50 volt

public input no. 140-nfpa 79-2016 [ global input ]...nema ics 2, industrial control and systems:...

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