ISA 12.12.01

Applicable to Class I and II, Division 2 and Class III,Divisions 1 and 2 locations

This standard applies only to equipment, circuits, andcomponents for use in Class I and II, Division 2 and Class III,Divisions 1 and 2 hazardous (classified) locations as defined inthe National Electrical Code^® (NEC^®)ANSI/NFPA 70 or in the Canadian Electrical Code (CEC) CSAC22.1.

NOTE 1 Some equipment designed for use in unclassified locationsis permitted by the NEC^® or CEC for installation inDivision 2 locations. The judgment of acceptability for theinstallation would be determined by the authority havingjurisdiction. Such equipment would not have the hazardous locationmarking or documentation described in this standard. It isanticipated that such equipment would comply with the otherrequirements in this standard and that the determination ofcompliance is elementary (e.g., a nonarcing instrument inside aType 4 or Type 12 enclosure used in a Class II, Division 2location).

NOTE 2 Throughout this standard, reference to CAN/CSA C22.2 No.60079-0 and ANSI/ISA 60079-0 are made as CSA/ISA 60079-0. Similarlyreference to CAN/CSA C22.2 No. 60079-1 and ANSI/ISA 60079-1 aremade as CSA/ISA 60079-1. Similarly reference to CAN/CSA C22.2 No.60079-11 and ANSI/ISA 60079-11 are made as CSA/ISA 60079- 11.Similarly reference to CAN/CSA C22.2 No. 60079-15 and ANSI/ISA60079-15 are made as CSA/ISA 60079-15.

NOTE 3 The US and Canadian adoptions of IEC 60079-0, IEC60079-1, IEC 60079-11 and IEC 60079-15 may be adopted at differentrevision levels and may have different National Deviations.

Applicable to associated nonincendive field wiringapparatus 

This standard also applies to associated nonincendive fieldwiring apparatus located in a nonhazardous (unclassified) locationspecifically designed to directly connect to nonincendive fieldwiring in Class I and II, Division 2 and Class III, Divisions 1 and2 hazardous (classified) locations.

NOTE The 2015 CEC does not address nonincendive field wiringcircuits in Class II or Class III hazardous locations.

Applicable ambient conditions

The requirements of this standard are based on consideration ofthe following ambient conditions:

a) A lower ambient temperature of -50°C or higher.

b) An upper ambient temperature of 40 °C or lower.

c) An oxygen concentration of not greater than 21 percent byvolume.

d) A pressure of 80 kPa (0.8 bar) to 110 kPa (1.1 bar) .

NOTE Equipment specified for atmospheric conditions beyond theabove limits may be subject to additional investigation.

Not applicable to specified ignition mechanisms

This standard is not applicable to mechanisms of ignition fromexternal sources, such as static electricity or lightning, that arenot related to the electrical characteristics of the equipment.

Not applicable to specific products

This standard does not apply to electric luminaires for use inDivision 2 hazardous (classified) locations.

This standard does not apply to electric motors, electricheaters, heat tracing cables, and similar heat-producing products,except where they are an integral part of the equipment underevaluation, for use in Division 2 locations. Where electric motors,electric heaters, heat tracing cables or similar heat-producingproducts are an integral part of the equipment under evaluation,applicable requirements from the Division 2 hazardous locationsstandards for these products shall be considered.

In the United States, this standard does not apply tobattery-operated flashlights and lanterns within the scope ofANSI/UL 783.

Purpose

The purpose of this standard is to provide minimumrequirements for the design, construction,and markingof electrical equipment or parts of such equipment for use in ClassI and Class I I, Division 2 and Class III, Divisions 1 and2hazardous(classified) locations.

This equipment, in normal operation, is not capable ofcausing ignition of the surrounding atmosphere underthe conditions prescribed in this standard, although the equipmentmaycontainelectronic components used in anincendivecircuit and may also have field wiringthat is anincendivecircuit.

In addition, it is the intent of this document toestablish uniformity in test methods fordeterminingthe suitability of the equipment andassociated circuits and components as they relate to potentialignition of a specific flammable gas or vapour -in-air mixture,combustible dust, easily ignitible fibers, or flyings.

Edition:

15

Published:

08/21/2015

ANSI:

ANSI Approved

Number of Pages:

54

File Size:

1 file , 780 KB