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Standard

ISA-12.12.01-2007

Nonincendive Electrical

Equipment for Use inClass I and II, Division 2and Class III, Divisions 1and 2 Hazardous(Classified) Locations

Draft 4March 2007

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ISA-12.12.01-2007Nonincendive Electrical Equipment for Use in Class I and II, Division 2 and Class III, Divisions 1and 2 Hazardous (Classified) Locations

ISBN:

Copyright 2007 by ISA. All rights reserved. Not for resale. Printed in the United States ofAmerica. No part of this publication may be reproduced, stored in a retrieval system, or

transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, orotherwise), without the prior written permission of the Publisher.

ISA67 Alexander DriveP. O. Box 12277Research Triangle Park, North Carolina 27709

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Preface

This preface, as well as all footnotes and annexes, is included for information purposes and is notpart of ISA-12.12.01-2007.

This Standard has been prepared as part of the service of ISA toward a goal of uniformity in thefield of instrumentation. To be of real value, this document should not be static but should besubject to periodic review. Toward this end, the Society welcomes all comments and criticismsand asks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: [email protected].

The ISA Standards and Practices Department is aware of the growing need for attention to themetric system of units in general, and the International System of Units (SI) in particular, in thepreparation of instrumentation standards. The Department is further aware of the benefits to USAusers of ISA standards of incorporating suitable references to the SI (and the metric system) intheir business and professional dealings with other countries. Toward this end, this Departmentwill endeavor to introduce SI-acceptable metric units in all new and revised standards,recommended practices, and technical reports to the greatest extent possible. Standard for Useof the International System of Units (SI): The Modern Metric System, published by the AmericanSociety for Testing & Materials as IEEE/ASTM SI 10-97, and future revisions, will be the referenceguide for definitions, symbols, abbreviations, and conversion factors.

It is the policy of ISA to encourage and welcome the participation of all concerned individuals andinterests in the development of ISA standards, recommended practices, and technical reports.Participation in the ISA standards-making process by an individual in no way constitutesendorsement by the employer of that individual, of ISA, or of any of the standards, recommendedpractices, and technical reports that ISA develops.

The following people served as members of ISA Subcommittee SP12.12:

NAME COMPANY

R. Masek, Chair CSA InternationalM. Coppler*, Managing Director Ametek Inc.N. Abbatiello Optimation TechnologyR. Allen Honeywell Inc.S. Arnold* Ametek DrexelbrookA. Ballard Crouse Hinds Division of Cooper IndustriesW. Bennett Mine Safety Appliances CompanyD. Bishop David N. Bishop ConsultantH. Bockle R. Stahl Inc.K. Boegli Phoenix Contact Inc.J. Bossert Hazloc Inc.

E. Briesch Underwriters Laboratories Inc.R. Cardinal Bentley Nevada LLCJ. Dolphin PSC SolutionsA. Engler Det Norske Veritas DNVW. Fiske Intertek Testing ServicesG. Garcha GE EnergyP. Hamer Chevron Texaco Corp. Research & Tech. Co.D. Hohenstein Pepperl+Fuchs Inc.G. Kozinski GE Infrastructure Sensing

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J. Kuczka KillarkC. Kurtzman Rosemount Inc.B. Larson Turck Inc.E. Legenski The WorleyParsons GroupN. Ludlam FM ApprovalsE. Massey Rockwell AutomationJ. Miller Detector Electronics CorporationO. Murphy Brooks InstrumentC. Oudar ExLoc CorporationD. Pace Olin CorporationJ. Propst Equilon EnterprisesV. Salupo Eli Lilly & CompanyA. Stafford ConsultantD. Wechsler Dow Chemical CompanyR. Wigg E-x Solutions International Pty. Ltd.

The following people served as members of ISA Committee SP12:

NAME COMPANY

T. Schnaare, Chair Rosemount Inc.W. Lawrence, Vice Chair FM ApprovalsM. Coppler, Managing Director Ametek Inc.D. Ankele Underwriters Laboratories Inc.A. Ballard Crouse Hinds Division of Cooper IndustriesD. Bishop David N Bishop ConsultantH. Bockle R. Stahl Inc.K. Boegli Phoenix Contact Inc.D. Burns Shell Exploration & Production CompanyR. Cardinal Bently Nevada LLCC. Casso Nabors IndustriesS. Czaniecki Intrinsic Safety Concepts Inc.J. Dolphin PSC Solutions

T. Dubaniewicz NIOSHA. Engler Det Norske Veritas DNVW. Fiske Intertek Testing ServicesG. Garcha GE EnergyD. Hohenstein Pepperl+Fuchs Inc.D. Jagger Bifold-Fluid PowerF. Kent Honeywell Inc.P. Kovscek Industrial Scientific Corp.J. Kuczka KillarkB. Larson Turck Inc.R. Masek* CSA InternationalE. Massey Rockwell AutomationA. Mobley 3M CompanyS. Nguyen Siemens Milltronics Ltd.

A. Page MSHA Approval & Certification CentreP. Schimmoeller* CSA InternationalR. Seitz Artech EngineeringD. Wechsler Dow Chemical CompanyR. Wigg E-x Solutions International Pty. Ltd.______* One vote per company.

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This standard was approved for publication by the ISA Standards and Practices Board on________________.

NAME COMPANY

T. McAvinew, Vice President Jacobs Engineering GroupM. Coppler Ametek Inc.B. Dumortier Schneider ElectricD. Dunn Aramco Services CompanyW. Holland ConsultantE. Icayan ACES Inc.J. Jamison Husky Energy Inc.K. Lindner Endress+Hauser Process Solutions AGV. Maggioli Feltronics CorporationA. McCauley Chagrin Valley Controls Inc.G. McFarland Emerson Process Mgmt Power & Water SolutionsR. Reimer Rockwell AutomationN. Sands E I du PontH. Sasajima Yamatake CorporationT. Schnaare Rosemount Inc.

J. Tatera Tatera & Associates Inc.I. Verhappen MTL Instrument GroupR. Webb Robert C Webb PEW. Weidman Worley ParsonsJ. Weiss Applied Control Solutions LLCM. Widmeyer ConsultantM. Zielinski Emerson Process Management

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7 ISA-12.12.01-2007

Contents

1 Purpose ........................................................................................................................... 92 Scope .............................................................................................................................. 93

Definitions ...................................................................................................................... 10

4 General requirements ..................................................................................................... 135 Requirements for Class I, Division 2 equipment .............................................................. 146 Requirements for Class II, Division 2, Class III, Divisions 1 and 2 equipment .................. 147 Nonincendive circuits and nonincendive field wiring ........................................................ 158 Normally nonarcing components ..................................................................................... 259 Marking .......................................................................................................................... 2610 Surface temperature requirements.................................................................................. 2811 Evaluation of nonincendive circuits ................................................................................. 3012 Evaluation of nonincendive components ......................................................................... 3313 Evaluation of sealed device ............................................................................................ 3414 Evaluation of enclosures for Class II and III .................................................................... 3515 Drop tests and impact tests ............................................................................................ 3716 Manufacturer's instructional manual................................................................................ 38Annex A Normative references ......................................................................................... 41Annex B Common standards safety requirements for electrical equipment

(informative)................................................................................................................... 43

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1 Purpose

The purpose of this standard is to provide minimum requirements for the design, construction, andmarking of electrical equipment or parts of such equipment for use in Class I and Class II,Division 2 and Class III, Divisions 1 and 2 hazardous (classified) locations. This equipment, in

normal operation, is not capable of causing ignition of the surrounding atmosphere under theconditions prescribed in this standard, although the equipment may contain electronic componentsthat operate at incendive levels and may also have field wiring that is incendive. In addition, it isthe intent of this document to establish uniformity in test methods for determining the suitability ofthe equipment and associated circuits and components as they relate to potential ignition of aspecific flammable gas or vapour-in-air mixture, combustible dust, easily ignitible fibers, or flyings.

2 Scope

2.1 This standard applies only to equipment, circuits, and components designed specifically foruse in Class I and II, Division 2 and Class III, Divisions 1 and 2 hazardous (classified)

locations as defined in the National Electrical Code (NEC

) ANSI/NFPA 70.

NOTE Some equipment designed for use in unclassifi ed locations is permitted by the NEC

forinstalling in Division 2 locations. The judgment of acceptability for the installation would be determinedby the authority having jurisdiction. Such equipment would not have the hazardous location marking ordocumentation described in this standard. It is anticipated that such equipment would comply with theother requirements in this standard and that the determination of compliance is elementary (e.g., anonarcing instrument inside a NEMA Type 4 or 12 enclosure used in a Class II, Division 2 location).

2.2 This standard also applies to certain unclassified location equipment specifically designedto directly connect to nonincendive field wiring in Class I and II, Division 2 and Class III,Divisions 1 and 2 hazardous (classified) locations as defined in the NEC

.

2.3 This standard is primarily intended to provide requirements for electrical and electronic test,measuring, and controlling equipment.

2.4 This standard is concerned only with equipment construction and test criteria related to

electrical or thermal ignition of specified flammable gases, vapors, combustible dusts,fibers, and flyings in air.

2.5 This standard is not intended to cover equipment for use in Class I and Class II, Division 1locations, such as equipment constructed to be intrinsically safe, dust ignition-proof, orexplosion-proof. Such equipment is, however, suitable for use in Class I and Class II,Division 2 locations in the same group and temperature class for which it is suitable inDivision 1.

2.6 This standard does not cover mechanisms of ignition from external sources, such as staticelectricity or lightning, that are not related to the electrical characteristics of the equipment.

2.7 This standard is not intended as an instructional manual for untrained persons. It isintended to promote uniformity of practice among those skilled in the area of design,

construction, and application of equipment suitable for Class I and Class II, Division 2 andClass III, Divisions 1 and 2 locations.

2.8 The requirements of this standard are based on consideration of ignition in locations madehazardous by the presence of flammable gases, vapors, combustible dusts, f ibers, andflyings under the following ambient conditions:

a) an ambient temperature of -25C to 40C

b) an oxygen concentration of not greater than 21 percent by volume

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c) a pressure of 80 kPa (0.8 bar) to 110 kPa (1.1 bar)

NOTE If equipment is specified to operate in conditions outside the ranges listed above, the requirements ofthis standard may not ensure the desired level of safety.

2.9 This standard covers portable battery-powered equipment other than flashlights andlanterns for Class I and Class II, Division 2, and Class III, Divisions 1 and 2 hazardous(classified) locations.

2.10 This standard does not cover electric luminaires for use in Division 2 hazardous (classified)locations.

2.11 This standard does not cover electric motors, electric heaters, heat tracing cables, andsimilar heat-producing devices, except where they are an integral part of the equipmentunder evaluation, for use in Division 2 locations.

2.12 This standard does not cover AEx requirements for equipment for use in Class I, Zone 2hazardous (classified) locations.

2.13 This standard does not cover the requirements for equipment for use in Zone 20, Zone 21or Zone 22.

3 Definitions

For the purposes of this standard, the following definitions apply.

3.1associated nonincendive field wiring apparatusapparatus in which the circuits are not necessarily nonincendive themselves, but that affect theenergy in nonincendive field wiring circuits and are relied upon to maintain nonincendive energylevels. Associated nonincendive field wiring apparatus may be either of the following:

a) Electrical apparatus that has an alternative type of protection for use in the appropriatehazardous (classified) location

b) Electrical apparatus not so protected that shall not be used in a hazardous (classified) location

NOTE Associated nonincendive field wiri ng apparatus has designated associated nonincendive field wiri ng

apparatus connections for nonincendive field wiring apparatus and may also have connections for other electrical

apparatus.

3.2control drawinga drawing or other document provided by the manufacturer of the nonincendive field wiringapparatus or the associated nonincendive field wiring apparatus that details the allowedinterconnections with other circuits or equipment. The control drawing includes the applicableelectrical parameters to permit selection of equipment for interconnection.

3.3

dust-tightenclosures constructed so that dust will not enter under specified test conditions.

3.4hermetically sealed devicea device that is sealed against the entrance of an external atmosphere and in which the seal ismade by fusion; e.g., soldering, brazing, welding, or the fusion of glass to metal.

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3.5maintenance, correctiveany maintenance activity that is not normal in the operation of the equipment and requires accessto the equipment's interior. Such activities are expected to be performed by qualified personnelwho are aware of the hazards involved. Such activities typically include locating causes of faultyperformance, replacing defective components, and adjusting service controls.

3.6maintenance, operationalany maintenance activity, excluding corrective maintenance, that is intended to be performed bythe operator and is required for the equipment to serve its intended purpose. Such operationalmaintenance activities typically include the correcting of "zero" on a panel instrument, changingcharts, keeping of records, and adding ink.

3.7make/break componentscomponents having contacts that can interrupt a circuit (even if the interruption is transient innature). Examples of make/break components are relays, circuit breakers, servo potentiometers,adjustable resistors, switches, and connectors.

3.8maximum external capacitance (Ca)maximum value of capacitance in a circuit that can be connected to the connection facilities of theassociated nonincendive field wiring apparatus.

3.9maximum external inductance (La)maximum value of inductance in a circuit that can be connected to the connection facilities of theassociated nonincendive field wiring apparatus.

3.10

maximum external inductance to resistance ratio (La/Ra)ratio of inductance (La) to resistance (Ra) of any external circuit that can be connected to theconnection facilities of the associated nonincendive field wiring apparatus.

3.11maximum input power (Pi)maximum power in an external circuit that can be applied to the connection facilities of thenonincendive field wiring apparatus.

3.12maximum input voltage (Vmax)maximum voltage (peak a.c. or d.c.) that can be applied to the connection facilities of thenonincendive field wiring apparatus.

3.13maximum internal capacitance (Ci)total equivalent internal capacitance which is considered as appearing across the connectionfacilities of the nonincendive field wiring apparatus.

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3.14maximum internal inductance (L i)total equivalent internal inductance which is considered as appearing at the connection facilities ofthe nonincendive field wiring apparatus.

3.15

maximum internal inductance to resistance ratio (L i /R i)ratio of inductance (Li) to resistance (Ri) that is considered as appearing at the connectionfacilities of the nonincendive field wiring apparatus.

3.16maximum output current (Isc)maximum output current (peak a.c. or d.c.) in a circuit that can be taken from the connectionfacilities of the associated nonincendive field wiring apparatus under normal operation.

3.17maximum output voltage (Voc)maximum output voltage (peak a.c. or d.c.) in a circuit that can appear under open-circuitconditions at the connection facilities of the associated nonincendive field wiring apparatus undernormal operation.

3.18maximum output power (Po)maximum electrical power in a circuit that can be taken from the connection facilities of theassociated nonincendive field wiring apparatus under normal operation.

3.19nonincendive circuita circuit, other than nonincendive field wiring, in which any arc or thermal effect produced undernormal operating conditions, is not capable of igniting the flammable gas-, vapor-, dust-air mixture,fibers or flyings. The circuit is evaluated under prescribed test conditions.

3.20nonincendive componenta component having contacts for making or breaking an incendive circuit and the contactingmechanism is constructed so that the component, under normal operating conditions, is not capableof igniting the flammable gas or vapor-air mixture. The housing of a nonincendive component isnot intended to exclude the flammable atmosphere or contain an explosion. The component isevaluated under prescribed test conditions.

3.21nonincendive equipmentequipment having electrical/electronic circuitry that is not capable, under normal operatingconditions, of causing ignition of a specified flammable gas-, vapor-, dust-air mixture fibers or

flyings due to arcing or thermal means.

3.22nonincendive field wiringwiring that enters or leaves an equipment enclosure and, under normal operating conditions of theequipment, is not capable, due to arcing or thermal effects, of igniting the flammable gas-, vapor-,dust- air mixture, fibers or flyings. Normal operation includes opening, shorting, or grounding thefield wiring.

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3.23nonincendive field wiring apparatusnonincendive equipment intended to be connected to nonincendive field wiring.

3.24normal operating conditions

conditions under which equipment conforms electrically and mechanically with its designspecification and is used within the conditions specified by the manufacturer. These conditionsinclude

a) supply voltage, current , and frequency;

b) environmental conditions (including process interface);

c) all tool-removable parts (e.g., covers) in place;

d) all operator-accessible adjustments at their most unfavorable settings; and

e) opening or grounding of any one or shorting of any two of the nonincendive field-wiringconductors.

3.25

operator-accessiblereadily accessible to the operator during normal use without use of a tool.

3.26sealed devicea device so constructed that it cannot be opened during normal operational conditions oroperational maintenance; it is sealed to restrict entry of an external atmosphere.

3.27unclassified locationslocations that have been evaluated by the classification process defined in ANSI/NFPA 70: anddetermined to be not Class I, Division 1; Class I, Division 2; Class I, Zone 0; Class I, Zone 1;Class I, Zone 2; Class II, Division 1; Class II, Division 2; Class III, Division 1; Class III, Division 2;Zone 20; Zone 21; Zone 22; or any combination thereof.

3.28maximum input current (Imax)maximum current (peak a.c. or d.c.) that can be applied to the connection facilities of thenonincendive field wiring apparatus.

3.29incendive circuita circuit, in which any arc or thermal effect produced under normal operating conditions, iscapable of igniting the flammable gas-, vapor-, dust-air mixture, fibers or flyings.

4 General requirements

Requirements for equipment intended to be used in Class I and Class II, Division 2 and Class III,Divisions 1 and 2 hazardous (classified) locations are established on the basis that the equipmentin its normal operating condition is not capable of causing ignition of a specified flammable gas,vapor-in-air mixture, dust, fibers, or flyings. The tolerances associated with the components of theequipment shall be considered. Subsequent arcs or thermal effects within the equipment, resultingfrom opening, shorting, or grounding of nonincendive field wiring, shall be taken into consideration

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as they affect the suitability of the equipment for use in Division 2 locations. Equipment also shallcomply with the unclassified location requirements for the particular category of equipment exceptas specifically amended herein (see Annex B).

5 Requirements for Class I, Division 2 equipment

5.1 Protection shall be provided according to 5.1.1 and 5.1.2 to ensure that under normaloperating conditions such equipment is not capable of igniting the specified f lammable gasor vapor-in-air mixture.

5.1.1 Each make/break component shall be either

a) a normally nonarcing component that meets the requirements of Clause 8;

b) used in a nonincendive circuit that meets the requirements of Clause 7;

c) a nonincendive component that meets the requirements of Clause 12; or

d) a sealed device that meets the requirements of Clause 13.

5.1.2 Equipment shall comply with the thermal ignition requirements of Clause 10.

5.2 Enclosures shall provide a suitable degree of protection against deterioration of theequipment that would adversely affect its suitability for use in Class I, Division 2 locations.

NOTE Although general-purpose enclosures normall y will suffice, particular attention should be given to the possibleneed for weatherproofing, general protection from corrosion (for further information see ANSI/UL 50 or ANSI/NEMA250, Enclosures for Electrical Equipment) and to preventive maintenance .

5.3 Fuses used in circuits that are subject to overloading in normal use shall be of a typesuitable for use in Division 2 locations or housed in an enclosure suitable for Division 1locations.

NOTE This subclause precludes a fuse housed in a general-purpose enclosure from being used in a motor circuitwhere a possibility of a stalled motor opening the fuse exists, or where there is the possibility of an overload not causedby a fault in the circuit.

5.4 If a replaceable fuse is provided, a switch suitable for the location where it is installed shallalso be provided to remove power from the fuse. The switch need not be integral to theequipment if the equipment installation instructions indicate the need for such a switch.

5.5 A circuit breaker that may be used as a switch shall be of a type suitable for use inDivision 2 locations or alternatively protected for use inDivision 1 locations.

6 Requirements for Class II, Division 2, Class III, Divisions 1 and 2 equipment

6.1 For Class II, Division 2 equipment, protection shall be provided by the use of an enclosurethat meets the requirements of Clause 13 or 14 or shall be a nonincendive circuit meetingthe requirements of Clause 7, with consideration for possible ignition in accordance with 7.2due to the ingress of dust or by a combination of these methods. For Class III locations,

protection shall be provided by a dust-tight enclosure that meets the requirements ofClause 14.

Consideration shall be given to shorting or bypassing components by Class II Group E orClass II Group F dusts.

EXCEPTION: Portable battery-powered equipment marked for use in Class II Group G or Class IIIonly need not have all electrical components and wiring enclosed provided both the followingconditions are met:

a) Entrance or accumulation of dust does not result in ignition or charring of the dust

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b) Circuits with make/break components shall be determined to be nonincendive with a propane-air mixture in accordance with the spark-ignition test (see 11.1 through 11.5, or 7.1).

7 Nonincendive circuits and nonincendive field wiring

7.1 Either of the following two methods may be employed to determine that a circuit(s) or f ield

wiring is nonincendive:

a) Testing the circuit according to Clause 11

b) Comparing the maximum calculated or measured values of current, voltage, and associatedinductances and capacitances to the appropriate values in Figures 1 through 8 to establishthat the current and voltage levels are below those specified in 7.3; for Class II and IIIlocations the curves for propane are to be used.

7.2 When evaluating a circuit as nonincendive, the following ignition sources shall beconsidered:

a) Discharge of capacitive circuits

b) Interruption of inductive circuits

c) Intermittent making and breaking of resistive circuits

d) opening or grounding of any one or shorting of any two of the nonincendive field-wiringconductors

7.3 The maximum voltage and current levels (d.c. or a.c. peak) in circuits determined to benonincendive by the comparison method, for given circuit constants, shall be less than

a) the current from Figures 1 through 6; and

b) the voltage from Figures 7 and 8.

The maximum normal output voltage and the maximum short-circuit current shall be determinedunder the worst-case normal operation.

NOTE Figures 1 and 2 apply only to circuits whose output voltage/current characteristic is a straight line drawnbetween open-circuit voltage and short-circui t current. Circuits with nonlinear outputs are subject to specialinvestigation.

7.4 For evaluating associated nonincendive field wiring apparatus, use the maximum outputvoltage (Voc), and maximum output current (Isc) with the applicable ignition Figures 1 to 8 todetermine the maximum external capacitance (Ca) and maximum external inductance (La).

7.5 For evaluating nonincendive field wiring apparatus, determine the maximum internalcapacitance (Ci) and maximum internal inductance (Li). These parameters shall be belowthe limits shown in Figures 1 to 8 based on the maximum input voltage (Vmax) and themaximum input current (Imax) of the nonincendive field wiring apparatus.

7.6 For nonincendive field wiring circuit evaluations the maximum input voltage (Vmax) of thenonincendive field wiring apparatus shall be equal to or greater than the maximum outputvoltage (Voc) of the associated nonincendive field wiring apparatus. Additionally, themaximum input current (Imax) of the nonincendive field wiring apparatus shall be equal to orgreater than the maximum output current (I sc) of the associated nonincendive field wiringapparatus.

EXCEPTION: For nonincendive field wiring apparatus that controls its own operating current, themaximum input current (Imax) of the nonincendive field wiring apparatus need not correspond tothe maximum output current (Isc) of the associated nonincendive field wiring apparatus (e.g.,4-20 mA measurement and control devices). Likewise, the maximum input voltage (Vmax) of

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nonincendive field wiring apparatus that controls its own normal operating voltage need not begreater than the maximum output voltage (Voc) of the associated nonincendive field wiringapparatus (e.g., current to pressure valve controllers that are voltage clamped at the terminals).Details of the permitted connections shall be provided on a control drawing.

7.7 Nonincendive field wiring enables interconnection of nonincendive field wiring apparatus

with associated nonincendive field wiring apparatus not specifically examined incombination as a system when one of the following conditions is true:

a) Normal operating voltage or current not controlled by the nonincendive field wiring apparatus

Vmax Voc; Imax Isc; Ca Ci + C cable; La Li + Lcable

b) Normal operating current controlled by the nonincendive field wiring apparatus (Imax of thenonincendive field wiring apparatus need not be greater than the Isc of the associatednonincendive field wiring apparatus)

Vmax Voc; Ca Ci + Ccable; La Li + Lcable

c) Normal operating voltage controlled by the nonincendive field wiring apparatus (Vmax of thenonincendive field wiring apparatus need not be greater than the Voc of the associatednonincendive field wiring apparatus)

Imax Isc; Ca Ci + Ccable; La Li + Lcable

d) Normal operating current and voltage controlled by the nonincendive field wiring apparatus(neither Imax nor Vmax of the nonincendive field wiring apparatus need be greater than thecorresponding parameter of the associated nonincendive field wiring apparatus)

Ca Ci + C cable; La Li + L cable

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Figure 1 Resistance circuits (L5 H)

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Figure 2 Resistance circuits (L5 H)

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Figure 3 Inductance circuits

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Figure 7 Capacitance circuits

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Figure 8 Capacitance circuits

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8 Normally nonarcing components

8.1 Make/break components that are to be considered nonarcing in normal operation shallcomply with the requirements of 8.2 through 8.7, as applicable.

8.2 Connectors and plug-in components used in incendive circuits and incorporated within

equipment shall be considered normally nonarcing if disconnection is not required underoperational conditions and if they require a separating force of at least 15 N. If accessibleduring normal operating conditions, connectors in an incendive circuit shall be provided witha warning marking in accordance with 9.2.

EXCEPTION: Plug-in components need only pass a pull test of 3 times the mass of thecomponent.

8.3 In incendive circuits, fuses that are removable during normal operating conditions shall beremovable only with the use of a tool and require a separating force of at least 15 N. Thefuseholders for such fuses shall be provided with a warning marking in accordance with 9.2and located adjacent to the fuseholder.

EXCEPTION: Plug-in type fuses need only pass a pull test of 3 times the mass of the component.

8.4 Circuit breakers that cannot be manually switched off, i.e., have only a reset button, may beused in circuits that are not subject to overloading in normal use. All such circuit breakersshall be provided with a warning marking in accordance with 9.3 and located adjacent to thecircuit breaker.

8.5 In incendive circuits, removable lamps that are accessible during normal operatingconditions shall be removable only with the use of a tool. The lamp holders for such lampsshall be provided with a warning marking in accordance with 9.2 and located adjacent to thelampholder. The lamp shall be protected to prevent breakage of the bulb.

EXCEPTION: A tool need not be required to remove the lamp if the lamp is accessible only afterremoval of a separate protective cover. The cover need not require a tool to remove.

8.6 If accessible during normal operating conditions, connectors used for nonincendive fieldwiring shall not be interchangeable with other field wiring connectors.

EXCEPTION: Where interchange does not affect nonincendive circuits or where connectors areso identified that interchange is unlikely, interchangeable connectors are allowed.

8.7 If accessible only by the use of a tool, manually operated make/break components in anincendive circuit are considered normally nonarcing components.

NOTE Circuit breakers may be used in circuits that are not subject to overloading in normal use.

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9 Marking

9.1 In addition to the marking required for general-purpose equipment, the equipment shall bemarked with the following minimum information:

9.1.1 For equipment to be installed in a hazardous location, the hazardous location suitability:

Class, Division, and Group(s). In lieu of Group(s), a specific gas, vapor, or dust, fiber, orflying. Apparatus that at tains temperatures higher than 100C based on a 40C ambientor a higher marked ambient shall be marked either by the temperature code as given inTable 3, or by the specific temperature as measured according to 10.

9.1.2 For associated nonincendive field wiring apparatus, a statement that the equipmentprovides nonincendive field wiring outputs and the hazardous location suitability of theoutput: Class, Division, and Group(s). In lieu of Group(s), a specific gas, vapor, dust,fiber, or flying

9.1.3 Any other markings or cautions necessary for the installation and safe operation of theequipment

The international symbol may be used to refer the operator to an explanation in theequipment instructions.

9.2 Connectors, fuseholders, and lampholders required to be marked according to 8.2, 8.3, and8.5 shall be marked with the following or an equivalent warning:

WARNING: DO NOT REMOVE OR REPLACE WHILE CIRCUIT IS LIVE UNLESS THE AREA ISKNOWN TO BE FREE OF IGNITIBLE CONCENTRATIONS OF FLAMMABLE SUBSTANCES.

If practical, this marking shall be either on or adjacent to the component. Otherwise, this markingshall be displayed on a prominent place on the enclosure.

9.3 Circuit breakers, required to be marked according to 8.4, shall be marked with the following

or an equivalent warning:

WARNING: DO NOT RESET CIRCUIT BREAKER UNLESS POWER HAS BEEN REMOVEDFROM THE EQUIPMENT OR THE AREA IS KNOWN TO BE FREE OF IGNITIBLECONCENTRATIONS OF FLAMMABLE SUBSTANCES.

9.4 The following information shall either be marked on the equipment or contained in theControl drawing for equipment with nonincendive field wiring connections:

9.4.1 Connections for nonincendive field wiring shall be clearly identified

9.4.2 Associated nonincendive fie ld wiring apparatus

a) Voc

b) Isc

c) Ca

d) La

e) Po - (optional)

NOTE In addition to the above, parameter La/Ra may also be marked.

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9.4.3 Nonincendive field wiring apparatus

9.4.3.1 Normal operating voltage or current not controlled by the nonincendive field wiringapparatus

a) Vmax

b) Imax

c) Ci

d) Li

e) Pi - (optional)

9.4.3.2 Normal operating current controlled by the nonincendive field wiring apparatus

a) Vmax

b) Ci

c) Li

d) Pi (optional)

9.4.3.3 Normal operating voltage controlled by the nonincendive field wiring apparatusa) Imax

b) Ci

c) Li

d) Pi (optional)

9.4.3.4 Normal operating current and voltage controlled by the nonincendive field wiringapparatus

a) Ci

b) Li

c) Pi (optional)

EXCEPTION: Equipment supplied, as a system, including cables supplied for field wiring, needonly comply with 9.4.1.

NOTE 1 In addition to the above, parameter Li/R i may also be marked,.

NOTE 2 Ordinary locations standards such as ANSI/ISA-61010-1 require the marking of the rated values of the supply

voltages or rated range of the supply voltages, and either;

a) the maximum rated power in either watts or volt-amperes or

b) the maximum rated input current.

9.4.4 The control drawing reference shall be marked on the associated nonincendive fieldwiring apparatus and on the nonincendive field wiring apparatus.

9.5 In addition, equipment may be marked Class I, Zone 2 Group IIA (or IIB, or IIC asapplicable) and the operating temperature or temperature class. The temperature classshall be in accordance with 10.2. The correlation between Groups for Zones and Groups forDivisions are shown below.

Where the electrical equipment is suitable for use in a particular gas, the chemical formula orname of the gas shall follow the symbol II.

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Class I Division 2 Groups Class I Zone 2 Groups

A IICB (IIB + H2)C IIBD IIA

NOTE (IIB +H2) is not a Group as defined by the NEC.

9.6 For practical reasons the symbols used for voltage, current capacitance, inductance, andL/R ratio may be replaced by the symbols defined in ANSI/ISA-60079-0, ElectricalApparatus for Use in Class I, Zones 0, 1, & 2 Hazardous (Classified) Locations GeneralRequirements. A comparison is shown in the following table. Division and zone parametersshould not be mixed.

Table 1 Nonincendive field wiring apparatus parameters

Electrical ParameterDivision

parameters

Zoneparameters

Associated Nonincendive Field Wiring Apparatus

Maximum output voltage Voc Uo

Maximum output current Isc Io

Maximum output power Po Po

Maximum external capacitance Ca Co

Maximum external inductance La Lo

Maximum external inductance to resistance ratio La/Ra Lo/Ro

Nonincendive Field Wiring Apparatus

Maximum input voltage Vmax Ui

Maximum input current Imax Ii

Maximum internal capacitance Ci Ci

Maximum internal inductance Li Li

Maximum input power P i P i

Maximum internal inductance to resistance ratio Li/R i Li/R i

10 Surface temperature requirements

10.1 Determination of maximum surface temperature

The maximum temperature of any surface that may come in contact with a f lammable gas orvapor-in-air mixture, dust, fibers, or flyings shall be determined under normal operationalconditions. Such measurements need not be made on the internal parts of sealed devices.Measurements shall be made at any convenient ambient temperature, corrected linearly to 40Cor higher marked ambient.

Maximum surface temperature shall be determined for rated duty of the electrical equipment butwith the most unfavorable supply voltage between 90% and 110% of the rated voltage of theelectrical equipment, unless other applicable standards prescribe wider tolerances.

NOTE More than one temperature class may be established for different ambient temperatures.

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10.2 Surface temperature

The maximum surface temperature obtained during testing shall be used to determine theapplicable temperature class. The maximum surface temperature may be exceeded for smallcomponents meeting the requirements of 10.3.

10.3 Small components

Small components, for example transistors or resistors, whose temperature exceeds thatpermitted for the temperature classification, shall be acceptable providing that they conform toone of the following.

a) When tested in accordance with Clause 26.5.3 of ANSI/ISA-60079-0, small components shallnot cause ignition of the flammable mixture and any deformation or deterioration caused bythe higher temperature shall not impair the type of protection; or

b) For T4 classification, small components shall conform to Table 2; or

c) For T5 classification, the surface temperature of a component with a surface area smaller than

1 000 mm2 (excluding lead wires) shall not exceed 150 C.

Table 2 Assessment for T4 classification according to component sizeand ambient temperature

Total surface area excluding wireterminations

Requirement for T4 classification

< 20 mm2 Surface temperature 275 C

20 mm2

Power dissipation 1,3 W*

20 mm2 1 000 mm

2Surface temperature 200 C

* Reduced to 1,2 W with 60 C ambient temperature or 1,0 W with 80 C ambient temperature.

For potentiometers, the surface to be considered shall be that of the resistance element and not

the external surface of the component. The mounting arrangement and the heat-sinking andcooling effect of the overall potentiometer construction shall be taken into consideration during thetest. Temperature shall be measured on the track with that current which flows under the testconditions required by this standard. If this results in a resistance value of less than 10 % of thetrack resistance value, the measurements shall be carried out at 10 % of the track resistancevalue.

The surface temperature of components having a total surface area of not more than 1 000 mm2may exceed the temperature class marked on the electrical equipment, if they are not ignitioncapable with a safety margin of:

50 K for T1, T2 and T3;

25 K for T4, T5 and T6.

This safety margin shall be ensured by tests of the electrical equipment.

NOTE During the tests, the safety margin may be provided by increasing the ambient temperature.

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Table 3 Temperature classifications (T codes)

Degrees C Temperature Code

450 T1

300 T2

280 T2A

260 T2B

230 T2C

215 T2D

200 T3

180 T3A

165 T3B

160 T3C

135 T4

120 T4A

100 T5

85 T6

11 Evaluation of nonincendive circuits

11.1 The spark test apparatus used for performing ignition tests on circuits shall consist of anexplosion chamber at least 250 cm

3in volume, in which circuit-making and circuit-breaking

sparks can be produced in the presence of the prescribed test gas.

11.2 Components of the contact arrangement are a cadmium disc with 2 slots and 4 tungstenwires of 0,2 mm diameter, which slide over the disc. The free length of the tungsten wiresshall be 11 mm. The driving spindle, to which the tungsten wires are attached, shall make80 revolutions per minute. The spindle on which the cadmium disc is mounted shall revolvein the opposite direction. The ratio of the speeds of the driving spindle to the disc spindleshall be 50 to 12. The spindles shall be insulated from one another and from the housing.

See Figure 9. The explosion chamber shall be able to withstand pressures of 1 470 kPa orshall be provided with suitable pressure relief. When cadmium, zinc, or magnesium will notbe present, the cadmium disc may be replaced by a tin disc.

11.3 Gas mixture

11.3.1 For Group D, the test m ixture shall be 5,25 0,25 percent propane by volume in air.

11.3.2 For Group C, the test m ixture shall be 7,8 0,5 percent ethylene by volume in air.

11.3.3 For Groups A and B, the test mixture shall be 21 2 percent hydrogen by volume in air.

11.3.4 For Classes II and III, the test mixture shall be 5,25 0,25 percent propane by volume inair.

11.3.5 Apparatus that is intended for use in a specific gas or vapor-in-air may be tested in themost easily ignitable concentration of that gas or vapor-in-air mixture in lieu of themixtures specified in 11.3.1 through 11.3.4.

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Figure 9 Test apparatus for evaluating nonincendive circuits

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11.4 Sensitivity verification of spark test apparatus

11.4.1 The sensitivity of the spark test apparatus shall be verified before and after each testseries conducted in accordance with 11.4.2. The test apparatus shall be operated ina 24 V d.c. circuit containing a 95 mH air-core coil. The currents in these circuits shallbe set at the corresponding value given for the appropriate group in Tables 4 or 5, asapplicable.

11.4.2 Verification of the apparatus shall be satisfactory if ignition of the gas occurs within 400revolutions of the tungsten wire holder.

Table 4 Current in verification circuit - cadmium disk

Group Inductive Circuit

D 100 mA

C 65 mA

A & B 30 mA

Table 5 Current in verification circuit - tin disk

Group Inductive Circuit

D 110 mA

C 90 mA

A & B 50 mA

11.5 Tests

11.5.1 The spark test apparatus shall be connected in the circuit under test at each point wherea spark can normally occur, taking into account the requirements of this standard.

11.5.2 Ignition test conditions

There shall be no ignition of the test mixture under any of the following conditions:

a) For line-connected apparatus, the input voltage shall be increased to 110 percent of nominalline voltage.

b) All adjustments shall be set at their most unfavorable positions.

c) All circuits shall be tested for the following number of revolutions of the tungsten wire holder inthe spark test apparatus:

1) For d.c. circuits, not less than 400 revolutions - 200 revolutions at each polarity

2) For a.c. circuits, not less than 1000 revolutions

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11.5.3 The test apparatus shall be verified according to 11.4 after each ignition test. The ignitiontest shall be considered invalid if the verification test is unsatisfactory.

12 Evaluation of nonincendive components

12.1 Nonincendive components shall be subjected to the tests specified in 12.2.

12.1.1 A nonincendive component is limited in use to the rating for which it has beensatisfactorily tested according to 12.2.

12.1.2 Nonincendive components shall be preconditioned by being operated a minimum of 6 000times at the rate of approximately 6 times per minute while carrying their normalelectrical load.

12.2 Spark ignition test for nonincendive components

12.2.1 Following the preconditioning test, the nonincendive component shall be placed in asuitable test chamber of at least ten (10) times the volume of the device and connectedto an electrical load of 150 percent of the a.c. or d.c. current (maximum 75 percent power

factor if for a.c.) and at maximum voltage of the circuit for which the component is beingtested.

EXCEPTION: The 75 percent power factor requirement may be neglected for totally resistive loadsonly.

12.2.1.1 Components intended for use with high inrush current loads (e.g., motor or tungstenlamp loads) shall be subjected to overload testing that is representative of actualcircuit applications. Preconditioning and overload conditions shall be according to therequirements of national standards that cover these applications.

12.2.2 Nonincendive components shall be filled with and surrounded by a gas mixture accordingto 11.3.1 through 11.3.5. The samples should be prepared by using one of the methodsin 12.2.2.1 to 12.2.2.3 and then successfully withstand the test in 12.2.3.

12.2.2.1 Remove the housing adjacent to the contacts to permit free access of the air-gasmixture to the contacts.

12.2.2.2 Drill at least two holes in the enclosure that will assure propagation of an ignition fromthe inside to the outside of the enclosure. The test gas shall flow through the device.A tube may be connected to one of the holes for this purpose.

12.2.2.3 Draw a vacuum within the chamber and maintain the vacuum for 100 seconds. Fill thetest chamber with the specified air-gas mixture and maintain the concentration for 100seconds before applying the required electrical load. An explosion detection device(e.g., a pressure transducer) shall be connected to the device under test to detectignition.

12.2.3 The component shall be operated a minimum of 50 times at not less than 10-secondintervals, renewing the air-gas mixture after each set of 10 operations (or morefrequently, if necessary to ensure the presence of the air-gas mixture within thenonincendive component). There shall be no ignition of the air-gas mixture.

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13 Evaluation of sealed device

13.1 This subclause covers the requirements for electrical equipment or parts of electricalequipment or components that contain normally arcing parts or heat-producing surfacesthat, by their location in a sealed enclosure, are intended to be made incapable of causing

ignition of the specified gas or vapor-in-air mixtures at their most easily ignitableconcentration.

13.1.1 Hermetically sealed devices (see definition in Clause 3) shall be considered to meetthese requirements without test.

13.2 Except as permitted in 13.1.1, the free internal volume of the device shall be less than100 cm

3.

13.3 Resilient gasket seals or poured seals shall be arranged so that they are not subject tomechanical damage during normal operational conditions and shall retain their sealingproperties for the intended conditions of use.

13.3.1 Sealing and encapsulating material shall have softening or melting points at least 20K

higher than the maximum temperature of the material achieved during the tests specifiedin this standard.

13.4 A sealed device shall have structural integrity and shall be constructed of materials suitablefor the intended environment with full consideration for anticipated atmosphericcontaminants and corrosive compounds. The enclosure shall be sufficiently rugged towithstand normal handling and assembly operations without damage to any seals provided.

13.5 To ensure that damage affecting safety of operation will not occur during normaloperational conditions of the sealed device, three samples shall be preconditioned by ovenaging according to 13.5.1 and subjected to an air leakage test according to 13.5.2.

13.5.1 Oven aging

If the device contains a gasket or seal of elastomeric or thermoplastic material or a compositiongasket utilizing an elastomeric material, each sample shall be subjected to temperature aging in acirculating air oven in accordance with the following formula:

( )( )T1T0.06932685et =

where

t = the test time in hours

e = 2.7183

T = the aging temperature in C

T1 = the maximum rated operating temperature in C (40C minimum)

13.5.2 Air leakage test

Each of the samples shall pass one of the following tests:

a) At an initial temperature of 25C the test samples shall be immersed in water at a temperatureof 50C to a minimum depth of 25 mm for a minimum of 1 minute. If no bubbles emerge fromthe samples during this test, they are considered to be "sealed" for the purpose of thisstandard.

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b) The test sample shall be immersed to a minimum depth of 75 mm in water contained in anenclosure that can be partially evacuated. The air pressure within the enclosure shall then bereduced by 120 mm of mercury. If no visible bubbles emerge from the samples during thistest, samples are considered to be sealed for the purpose of this standard.

c) The test sample shall be shown to leak at a rate not greater than 10-5

ml of air per second at apressure differential of 1 atmosphere (101.3 kPa) by means of a suitable leak rate detector.

13.5.3 As an alternative to the test detailed in 13.5.1 a gasket of an elastomeric or thermoplasticmaterial, or a composition gasket utilizing an elastomeric material, shall be tested bysubmitting the enclosures to continuous storage for one week in an ambient of (90 5) %relative humidity and at a temperature of (20 2) K above the maximum servicetemperature but a t least 80 C.

In the case of a maximum service temperature above 75 C the period of one weekspecified above will be rep laced by a period of 85 hours at (95 2) C and (90 5) %relative humidity followed by a period of 85 hours at a temperature of (20 2) K higherthan the maximum service temperature.

14 Evaluation of enclosures for Class II and III

14.1 An enclosure that is required to exclude the entry of dust shall pass any one of the testsaccording to 14.2, 14.3, or 14.4.

14.1.1 For the tests in 14.2 or 14.4 a length of conduit may be installed in the enclosure undertest to equalize the internal and external pressures, but it shall not serve as a drain.

14.1.2 A gasket used to make an enclosure dust-tight shall be made of material acceptable forthe purpose, e.g., plant-fiber sheet packing or similar material. A gasket of elastomericor thermoplastic material may be used if it is resistant to aging when tested inaccordance with 14.1.3. Gaskets shall be either secured or captive if they could bedislodged during installation or maintenance of the apparatus.

14.1.3 Aging test

A gasket of an elastomeric or thermoplastic material, or a composition gasket utilizing anelastomeric material, shall be of such quality that samples have a tensile strength of not less than60 percent and an elongation of not less than 75 percent of values determined for unagedsamples, when subjected to temperature aging in a circulating air oven in accordance with thefollowing formula:

( )( )T1T0.06932685et =

where

t = the test time in hours

e = 2,7183T = the aging temperature in C

T1 = the maximum rated operating temperature in C (40C minimum)

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14.1.4 As an alternative to the test detailed in 14.1.3 a gasket of an elastomeric or thermoplasticmaterial, or a composition gasket utilizing an elastomeric material, shall be tested bysubmitting the enclosures to continuous storage for one week in an ambient of (90 5) %relative humidity and at a temperature of (20 2) K above the maximum servicetemperature but at least 80 C.

In the case of a maximum service temperature above 75 C the period of one weekspecified above will be replaced by a period of 85 hours at (95 2) C and (90 5) %relative humidity followed by a period of 85 hours at a temperature of (20 2) K higherthan the maximum service temperature.

14.2 Dust-blast method

The enclosure shall be subjected to a blast of compressed air mixed with dry Type 1 general-purpose Portland cement (or equivalent) using a suction-type sandblast gun that is equipped witha 4.8-mm diameter air jet and a 9.5-mm diameter nozzle. The air shall be at a supply pressure of620-690 kPa. The cement is to be supplied by a suction feed. A minimum of 6 kg/m of test length(sum of height, width, and depth) of the enclosure under test is to be applied at a minimum rate of2.3 kg per minute. The nozzle is to be held 305-381 mm from the enclosure, and the blast of airand cement is to be directed at all points of potential dust entry, such as, but not limited to,

seams, joints, and external operating mechanisms. There shall be no visible dust inside theenclosure at the end of this test.

14.3 Circulating dust method

The test is made using equipment in which talcum powder is maintained in suspension in asuitable closed chamber. The talcum powder used shall pass through a square-meshed sievewhose nominal wire diameter is 50 m and whose nominal width between wires is 75 m. Theamount of talcum powder used shall be 2 kg/m

3of the test chamber volume. It shall not have

been used for more than 20 tests.

Enclosures shall be determined to fit in one of two categories:

a) enclosures where the normal working cycle of the apparatus causes a reduction in the airpressure within the enclosure below the surrounding atmosphere (e.g., caused by thermalcycling effect); or

b) enclosures where reductions in pressure below the surrounding atmospheric pressure are notcaused by normal cycles of the apparatus.

For enclosures of category (a) the enclosure under test shall be supported inside the test chamberand the pressure inside the enclosure is maintained below the surrounding atmospheric pressureby a vacuum pump. The suction connection shall be made to a hole specifically provided for thistest. If not otherwise specified in the relevant product standard, this hole shall be in the vicinity ofthe vulnerable parts. If it is impracticable to make a special hole, the suction connection shall bemade to the cable inlet hole. If there are other holes (e.g. more cable inlet holes or drain holes)these shall be treated as intended for normal use on site. The object of this test is to draw into the

enclosure, by means of depression a volume of air 80 times the volume of the sample enclosuretested without exceeding the extraction rate of 60 volumes per hour. In no event shall thedepression exceed 2 kPa (20 mbar). If an extraction rate of 40 to 60 volumes per hour is obtainedthe duration of the test is 2 hours. If, with a maximum depression of 2 kPa (20 mbar) of water, theextraction rate is less than 40 volumes per hour, the test shall be continued until 80 volumes havebeen drawn through, or a period of 8 hours has elapsed . For an enclosure of category (b), theapparatus under test should be supported in its normal operating position inside the test chamber,but the test chamber shall not be connected to a vacuum pump. Any drain hole normally openshall be left open for the duration of the test. The test shall continue for a period of 8 hours.

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If it is not possible to place the complete assembly in the test chamber, one of the followingprocedures shall be used:

a) Individual testing of separate enclosed sections of the apparatus

b) Testing of representative parts of the apparatus (such as doors, ventilating openings, joints,and shaft seals), with the vulnerable parts of the apparatus (such as terminals and slip rings)

in position at the time of testingc) Testing of smaller apparatus having the same full-scale design details

The enclosure shall be deemed to pass the test if no visible dust is detected inside the enclosureat the end of the test.

14.4 Atomized-water method

The enclosure shall be sprayed with atomized water using a nozzle that produces a round pattern76-102 mm in diameter, 305 mm from the nozzle. The air pressure shall be 207 6 kPa. Thewater is to be supplied by a suction feed with a siphon height of 102-204 mm. A minimum of 485ml/m of test length (sum of height, width, and depth) of the enclosure under test shall be appliedat a minimum rate of 11 liters per hour. The nozzle shall be held 305-381 mm f rom the enclosure,

and the spray of water shall be directed at all points of potential dust entry including, but notlimited to, seams, joints, and external operating mechanisms. To pass the test there shall be novisible water inside the enclosure at the end of this test.

15 Drop tests and impact tests

15.1 Portable equipment (equipment intended to be carried by hand) shall be subjected to a droptest as specified in 15.2. There shall be no damage to the equipment that may affect itsacceptability for use in hazardous (classified) locations.

15.2 Equipment is to be dropped six times, not more than once on any one equipment surface,from a height of 0,9 m onto a smooth concrete floor. A nonrestrictive guide may be used.

15.3 Equipment with non-metallic enclosures or parts of enclosures intended for use in Class II,or Class III hazardous (Classified) locations shall be subject to a 2,7 joules impact test priorto dust tests.

15.3.1 The point(s) of impact shall be the place(s) considered to be the weakest. No locationshall be subjected to more than one impact. The equipment shall be tested completelyassembled, and with any guards installed that are normally supplied as part of theequipment. Ambient temperature for the test shall be 20C 5C except where theelectrical enclosure or parts of the enclosure are made from polymeric material. In thiscase, the impact tests shall be repeated at the lower ambient temperature of the deviceas marked on the equipment label or listed in the product literature.

15.3.2 The test mass shall be f itted with a steel hemisphere of 25 mm diameter. The equipment

shall be positioned on a steel or concrete base so the direction of impact is normal to thesurface being tested. The base shall have a mass of at least 20 kg.

15.4 Class I equipment shall be examined to ensure there is no damage to the equipment thatmay affect its acceptability for use in Division 2 locations after impact test specified in theapplicable standards for products in unclassified locations.

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16 Manufacturer's instructional manual

16.1 The manufacturer's instructional material shall include, in addition to the informationrequired for unclassified locations, the information shown in 16.2 through 16.5 toemphasize the precautions required when operating the equipment in a Division 2 location.

16.2 The following or equivalent specification for the location of the equipment shall be included:

This apparatus is suitable for use in Class (as applicable), Division 2 groups (as applicable), orunclassified locations.

16.3 The following or equivalent information for use of the equipment shall be included.

A control drawing shall be provided for all nonincendive field wiring apparatus or associatednonincendive field wiring apparatus. A nonincendive field wiring system could consist ofequipment investigated as a system or equipment investigated under the nonincendive field wiringconcept. If the nonincendive field wiring and the associated nonincendive field wiring areinvestigated as a system, the control drawing shall provide information for proper connection andinstallation. If the nonincendive field wiring or associated nonincendive field wiring apparatus is

investigated separately the control drawing shall include applicable electrical parameters to permitselection of apparatus for interconnection.

The control drawing shall contain notes to explain the following if applicable:

a) The polarity requirements for associated nonincendive field wiring apparatus

b) That associated nonincendive field wiring apparatus shall not be connected in parallel unlessthis is permitted by the associated nonincendive field wiring apparatus approval

c) How to calculate the allowed capacitance and inductance values for the field wiring used in thenonincendive field wiring circuit

d) The hazardous (classified) locations in which the apparatus may be located

e) Permissible connections to simple apparatus

The control drawing shall provide the following information where applicable, either the Divisionparameters, the Zone parameters, or both, as shown in Table 1, may be used to designateelectrical parameters on the apparatus and in the installation documents and control drawing.

16.4 If equipment contains sealed components the following shall be provided:

16.4.1 A warning such as: "WARNING: EXPOSURE TO SOME CHEMICALS MAY DEGRADETHE SEALING PROPERTIES OF MATERIALS USED IN THE FOLLOWING DEVICES";identification of the sealed devices

16.4.2 The list of materials used in the construction of these devices

Name of sealed device - generic name of the material and the supplier's name and type

designation.

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16.4.3 A recommendation for the user to periodically inspect the devices named above for anydegradation of properties and replace if degradation is found

16.5 The following warning or equivalent warnings for repair of the equipment shall be included:

16.5.1 If replacement of a component (e.g., fuse, lamp or plug-in module) could ignite theflammable atmosphere

WARNING: EXPLOSION HAZARD. DO NOT REMOVE OR REPLACE LAMPS, FUSES OR PLUG-IN MODULES (AS APPLICABLE) UNLESS POWER HAS BEEN DISCONNECTED OR THE AREAIS KNOWN TO BE FREE OF IGNITIBLE CONCENTRATIONS OF FLAMMABLE GASES ORVAPORS.

16.5.2 If disconnecting the equipment supply could ignite the flammable atmosphere

WARNING: EXPLOSION HAZARD. DO NOT DISCONNECT WHILE THE CIRCUIT IS LIVE ORUNLESS THE AREA IS KNOWN TO BE FREE OF IGNIT IBLE CONCENTRATIONS.

16.5.3 If components are relied upon to make the equipment suitable for Division 2 locations,these components shall be individually identified. The following is an example ofidentifying such components:

WARNING: SUBSTITUTION OF THE FOLLOWING COMPONENTS MAY IMPAIR SUITABILITYFOR DIVISION 2:

Reference designation Description Type of Protection

K3 Relay Sealed contacts

OL1 Thermal switch Hermetical ly sealed contacts

M1 Fan Brushless motor

S6 Switch Nonincendive component

16.6 Documentation accompanying nonincendive components that are not factory-installed inequipment shall state the circuit parameters for which the components have beendetermined to be safe.

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Annex A Normative references

The following referenced documents may be necessary for the application of this document. Fordated references, only the edition cited applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.

ANSI/NFPA 70:2005, National Electrical Code

ANSI/ISA-60079-0 (12.00.01)-2005, Electrical Apparatus for Use in Class I, Zones 0, 1 & 2Hazardous (Classified) Locations: General Requirements

ANSI/ISA-61010-1 (82.02.01)-2004, Safety Requirements for Electrical Equipment forMeasurement, Control, and Laboratory Use Part 1: General Requirements

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

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Annex B Common standards safety requirements for electricalequipment (informative)

The following are common standards used to verify conformance with safety requirements forelectrical equipment. This list is not comprehensive.

ANSI/ISA 61010-1 Safety Requirements for Electrical Equipment for Measurement, Control,and Laboratory Use Part 1: General Requirements

ANSI/UL 20 General-Use Snap SwitchesANSI/UL 50 Enclosures for Electrical EquipmentANSI/UL 67 PanelboardsANSI/UL 94 Tests for Flammability of Plastic Materials for Parts in Devices and

AppliancesANSI/UL 153 Portable Electric LampsANSI/UL 298 Portable Electric Hand LampsANSI/UL 347 High Voltage Industrial Control EquipmentANSI/UL 427 Refrigerating UnitsANSI/UL 429 Electrically Operated Valves

ANSI/UL 464 Audible Signal AppliancesANSI/UL 486A Wire Connectors and Soldering Lugs for Use with Copper ConductorsANSI/UL 486B Wire Connectors for Use with Aluminum ConductorsANSI/UL 486C Splicing Wire ConnectorsANSI/UL 486E Equipment Wiring Terminals for Use with Aluminum and/or Copper A

ConductorsANSI/UL 489 Molded-Case Circuit Breakers and Circuit-Breaker EnclosuresANSI/UL 498 Attachment Plugs and ReceptaclesANSI/UL 508 Industrial Control EquipmentANSI/UL 512 FuseholdersANSI/UL 514A Metallic Outlet BoxesANSI/UL 514B Fittings for Conduit and Outlet BoxesANSI/UL 514C Nonmetallic Outlet Boxes, Flush-Device Boxes, and Covers

ANSI/UL 595 Marine-Type Electric Lighting FixturesANSI/UL 746A Polymeric Materials Short Term Property EvaluationsANSI/UL 746B Polymeric Materials Long Term Property EvaluationsANSI/UL 746C Polymeric Materials Use in Electrical Equipment EvaluationsANSI/UL 746D Polymeric Materials Fabricated PartsANSI/UL 746E Polymeric Materials Industrial Laminates, Filament Wound TubingANSI/UL 840 Insulation Coordination Including Clearances and Creepage Distances

for Electrical EquipmentANSI/UL 864 Control Units for Fire Protective Signaling SystemsANSI/UL 873 Temperature-Indicating and -Regulating EquipmentANSI/UL 924 Emergency Lighting and Power EquipmentANSI/UL 943 Ground-Fault Circuit-InterruptersANSI/UL 984 Hermetic Refrigerant Motor-CompressorsANSI/UL 1004 Electric Motors

ANSI/UL 1053 Ground-Fault Sensing and Relaying EquipmentANSI/UL 1059 Terminal BlocksANSI/UL 1097 Double Insulation Systems for Use in Electrical EquipmentUL 1104 Marine Navigation LightsANSI/UL 1480 Speakers for Fire Protective Signaling SystemsANSI/UL 1481 Power Supplies for Fire Protective Signaling SystemsUL 1562 Transformers, Distribution, Dry-Type Over 600 VoltsANSI/UL 1585 Class 2 and Class 3 TransformersANSI/UL 1598 Luminaires

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ANSI/UL 1638 Visual Signaling Appliances Private Mode Emergency and GeneralUtility Signaling

UL 1682 Plugs, Receptacles, and Cable Connectors of the Pin and Sleeve TypeANSI/UL 1740 Industrial Robots and Robotic EquipmentANSI/UL 60950-1 Safety of Information Technology Equipment, Including Electrical

Business Equipment (Second Edition)ANSI/UL 1971 Signaling Devices for the Hearing ImpairedUL 2111 Overheating Protection for MotorsUL 2225 Metal-Clad Cables and Cable-Sealing Fittings for Use in Hazardous

(Classified) Locations

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Developing and promulgating sound consensus standards, recommended practices, and technicalreports is one of ISAs primary goals. To achieve this goal the Standards and PracticesDepartment relies on the technical expertise and efforts of volunteer committee members,chairmen and reviewers.

ISA is an American National Standards Institute (ANSI) accredited organization. ISA administersUnited States Technical Advisory Groups (USTAGs) and provides secretariat support forInternational Electrotechnical Commission (IEC) and International Organization forStandardization (ISO) committees that develop process measurement and control standards. Toobtain additional information on the Societys standards program, please write:

ISAAttn: Standards Department67 Alexander DriveP.O. Box 12277Research Triangle Park, NC 27709

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