Hazardous Location
Hazardous Area Guidelines for Compliant SCADA Systems
The suitability of equipment for specific hazardous areas in the North American regulated market is required to be tested by a NRTL (Nationally Recognized Testing Laboratory). This is a testing facility, recognized by OSHA (Occupational Safety & Health Administration), as primarily private sector organizations that provide product safety testing and certification services to manufacturers.
The testing and certification are done, for purposes of the program, to U.S. consensus-based product safety test standards. These test standards are not developed or issued by OSHA, but are issued by U.S. standards organizations, such as the American National Standards Institute (ANSI). Some well-known organizations currently recognized by OSHA as NRTL’s include (but are not limited to):
Canadian Standards Association (CSA); FM Approvals LLC (FM); and Underwriters Labs Inc (UL)
Refer to Article 500 of the National Electrical Code, publication NFPA 70, or Section 18 of the Canadian Electrical Code, publication C22.1 for complete definitions of hazardous areas. For our purposes, a brief recap follows:
Hazardous Location (classified) is a North American term for locations where the potential for fire or explosion exists because of gases, dust, or easily ignitable fibers or filings in the atmosphere.
Such an area is categorized according to the nature of the risk and the relative risk level.
To define the level of safety required for equipment installed in these locations, Classes, Divisions, and Groups separate the different hazardous areas:
Classes define the general form of the flammable materials in the atmosphere.
Divisions define the probability of the presence of flammable materials.
Groups classify the exact flammable nature of the material.
A Class I Hazardous Location is one in which material may be present in the air in sufficient quantities to be explosive or ignitable. Some typical Class 1 locations are utility gas plants and operations involving storage and handling of liquefied petroleum gas or natural gas petroleum refineries gasoline storage and dispensing areas.
When the hazard would be expected to be present in everyday production operations or during frequent repair and maintenance activity, this is called the normal condition.
When the hazardous material is expected to be confined within closed containers or closed systems and will be present only through accidental rupture, breakage or unusual faulty operation, the situation could be called abnormal.
The Code writers designate these two kinds of conditions very simply: normal condition is deemed Division 1, and abnormal condition is known as Division 2. Thus:
Class I, Division 1 – Where ignitable concentrations of flammable gases, vapors or liquids are present within the atmosphere under normal (day to day) operating conditions.
Class I, Division 2 – Where ignitable concentrations of flammable gases, vapors, or liquids are present within the atmosphere under abnormal (system failure) operating conditions.
Groups A,B,C, & D designate the various types of flammability, and for the purposes of most SCADA applications, are quite secondary to the Class/Division rating.
With respect to SCADA systems, radio modems require certification ratings to operate in a hazardous area. Typically, commercially available gain antennas and virtually all surge suppressors are not rated. Due to increased demand for intrinsically safe wireless equipment, however, a growing number of unity gain omni-directional models certified for use in Class I Div 1 areas are more readily available.
Field services personnel seeking to meet the compliance requirements using (non-rated) directional antennas may consider the following:
* connect the cable and antenna in place on the mast before it is deployed in the restricted area, and
* install the antenna at a height that is deemed to be out of the Class I Division 2 zone:
typically this zone is understood to extend 25 feet outside the adjacent Division 1 zone.
As height is one of the most important considerations with respect to optimizing the operating characteristics of an antenna, this strategy works to the benefit of the site anyway.
About the Author
Good SCADA automation can become GREAT using optimum antenna technology incorporated into the design from the start. Visit us to learn more and see what great antenna options Wavelink Antenna Systems offers. Gary Tootle advises and supports wireless communications professionals throughout USA and Canada http://www.wavelinkantenna.com/contact.php
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Appleton Explosion Proof Plug ECP20232 Hazardous Location Plug $0.99 |
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NEW TRITON CDS T3CDS ORDINARY WET AND HAZARDOUS LOCATION CABLE CONNECTOR GLANDS $4.95 |
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HUBBELL KILLARK 1/2″ BREATHER HAZARDOUS LOCATIONS KB1B $7.00 |
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EC&M’s Practical Guide to Hazardous Locations $8.00 |
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Standard Transformer Low Voltage Hazardous Location Transformers 1958 print Ad $8.99 |
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Hazardous Classified Locations (Electrical Trades (W/O Electro)), Richard Loyd, $9.57 |
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2 NEW MIDLAND ROSS HAZARDOUS LOCATION ELECTRICAL CONNECTORS 30A 240V (C5-3-26) $9.99 |
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Crouse Hinds Outlet Box Cover 2.5″ for Hazardous Locations Type GUA 0101638 $9.99 |
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Student workbook: NJATC hazardous locations workbook $10.00 |
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THERMON JB-7 TYPE 4 ENCLOSURE FOR HAZARDOUS LOCATIONS $11.25 |
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BRANDT TRANSDUCER MODEL CPT3130 FOR HAZARDOUS LOCATIONS $11.25 |
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One 1″ Type C Outlet Box Hazardous Location GUAC-100 O-Z/Gedney $11.69 |
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Killark OLB-1CG Conduit Body Hazardous Location LB 1/2 Inch Hub $11.70 |
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Killark Explosion Proof Outlet Box Cover 3.5″ for Hazardous Locations GECBC $12.50 |
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Killark/Hubbell GUF-5, 1-1/4″ Hazardous Location Rated Aluminum Conduit Union $12.50 |
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Electrical installations in hazardous locations, Peter J Schram, Good Book $12.50 |
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Killark XLB-1 Aluminum Hazardous Location Conduit Body $12.74 |
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1″ Outlet Box Type L By O-Z/Gedney Hazardous Location W/ O ring GUAL-100 $12.99 |
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One 3/4″ Type C Outlet Box Hazardous Location GUAC-75 O-Z/Gedney $12.99 |
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One 1/2″ Type LB Outlet Box Hazardous Location GUALB-50 O-Z/Gedney $12.99 |
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2005 NEC code review-Guide for Use of Electrical Products in Hazardous Locations $13.50 |
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FENWAL 8843 FIRE DETECTION HEAT DETECTOR IN HAZARDOUS LOCATIONS 27121-0 $13.99 |
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POTTER & BRUMFIELD HAZARDOUS LOCATION RELAY KR-11DGE-24 $14.00 |
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KILLARK GUF-3 HAZARDOUS LOCATION 1″ ALUMINUM UNION NEW $14.88 |
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Hazardous Locations-International Association/Electrical Inspectors9781890659462 $15.00 |
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1″ GUAC – 100 Outlet Box – Type C Hazardous Location w/ O-Ring By Oz Gedney $16.24 |
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Crouse-Hinds 3/4″ Hubs Hazardous Location Iron Conduit Outlet Box GUAL26 $16.99 |
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THREE EYE Y CONDUIT CONNECTOR UNILET EXPLOSION PROOF HAZARDOUS LOCATION INV=348 $17.49 |
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CROUSE-HINDS 1″ GUAX 36 CONDUIT OUTLET BOX FOR HAZARDOUS LOCATIONS $18.00 |
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Unused Red Dot EXT-1 1/2″ “T” Hazardous Location Conduit Body. T-Style $18.00 |
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CROUSE HINDS CPS152A HAZARDOUS LOCATION RECEPTACLE $18.99 |
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O-Z Gedney 1/2″ Hazardous Location Exp Cond UNYE-50S Steel Zinc Plated NOS $18.99 |
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Ericson Vapor Gard Hazardous Location Hand Lamp $19.99 |
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Crouse Hinds UNF305 Hazardous Location 1″ Conduit Union $19.99 |
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OZ Gedney UNF-100S Hazardous Location 1″ Conduit Union $19.99 |
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O-Z GEDNEY TYPE GUAT-75 HAZARDOUS LOCATION OUTLET BOX $19.99 |
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Killark 90 Deg 1″ Elbow Fitting for Hazardous Locations B-10846 $19.99 |
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Killark 1/2″ Outlet Box for Hazardous Locations GECCT-1 $19.99 |
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Appleton Hazardous Location Sealing Fittings 1 1/2″ NPT $20.00 |
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NEW THERMON HAZARDOUS LOCATION OUTLET BOX NEMA 4 ECA-1 $20.00 |
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Crouse-Hinds Hazardous Location 2 Way Outlet Box 3/4″ New $20.00 |
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RL-21 1HP Manual Motor Starter 230V Hazardous Location $20.00 |
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Allen Bradley 800H Base for Hazardous Location $20.00 |
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New Killark XLB-3 Hazardous Location Conduit Body $21.24 |
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Condulet 3/4″ Hazardous Location Conduit Outlet Box W/ Cover EAJL26 $21.35 |
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PARKER SOLENOID VALVE FOR HAZARDOUS LOCATIONS $22.49 |
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CROUSE-HINDS ENP5201 HAZARDOUS LOCATION PLUG ***XLNT*** $24.00 |
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Square D 9007 CR61B2 Hazardous Location Limit Switch $24.50 |
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HOLOPHANE 09108-3 Hazardous Location Safety Chain $24.50 |
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NEW Hubbell Splice Box VXA-2, 3/4″ Size Hazardous Location Splice Box #28754 $24.95 |
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NOS! RELIANCE HAZARDOUS LOCATION OUTLET BOX 4118684A $24.95 |
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ALLEN BRADLEY ROLLER LIMIT SWITCH BULLETIN 802X TYPE 7-9 HAZARDOUS LOCATIONS $24.99 |
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1 1/2″ Union For Hazardous Locations $24.99 |
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DAYTON 1/2 HP MOTOR 3N368L FOR HAZARDOUS LOCATIONS $25.00 |
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Akron Instrument Enclosure For Hazardous Location Cat.no XJIHG5.MSD, p/n 1331AAB $25.00 |
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Gedney Hazardous Location Exp Conduit Unions 1/2″ Unfel-50S Steel Zinc Plated $25.00 |
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Unused Killark XLB-1 1/2″ LB-Style Hazardous Location Outlet Body $25.00 |
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NEW RED DOT 1/2″ EXLB FOR HAZARDOUS LOCATIONS $25.00 |
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NEW KILLARK #GEML-1 FOR HAZARDOUS LOCATIONS 1/2″ $25.00 |
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USED APPLETON #GR TYPE X 1/2″ FOR HAZARDOUS LOCATIONS $25.00 |
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Killark XLB-2 Aluminum Hazardous Location Conduit Body $25.49 |
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New Appleton 1/2″ ERLB Hazardous Location Outlet Body $25.49 |
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Crouse Hinds C2479 Hazardous Locations Electrical Outlet Box, New $28.00 |
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Appleton EDSC271 hazardous locations control assembly body 3/4″ $29.00 |
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Baldor Hazardous Location Electric Motor 1760-2700RPM 230-460V 0.43HP [55] $29.00 |
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Parker 04F30C2106ACFEC05 Gold Ring SOLENOID VALVE for Hazardous Locations $29.74 |
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NEW Hubbell Splice Box VXA-2, 3/4″ Size Hazardous Location Splice Box #28755 $29.95 |
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GE HAZARDOUS LOCATION LIGHT FIXTURE H5115L 150 WATT NEW $29.95 |
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CROUSE-HINDS GUAT-36 HAZARDOUS LOCATION 3-WAY EXPLOSION PROOF JUNCTION BOX $29.99 |
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RELIANCE DUTYMASTER A.C. MOTOR – P48H2302M SJ – 1/4 H.P FOR HAZARDOUS LOCATIONS $29.99 |
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ADALET X82-83 HAZARDOUS LOCATION EXPLOSION PROOF JUNCTION BOX USED $29.99 |
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Crouse-Hinds Hazardous Location Box 3/4″ Hubs $29.99 |
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RIG-A-LITE SRE45GL GLASS REFRACTOR HAZARDOUS LOCATIONS $29.99 |
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Crouse Hinds Arktite CPP 312 plug 20 amp for hazardous locations 1 HP/ 125-250 V $29.99 |
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APPLETON RB-250-200 Reducing Bushing 2-1/2″ to 2″- Hazardous Location-Mal Iron $29.99 |
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NEW KILLARK GECLT-1 1/2″ BOX FOR HAZARDOUS LOCATION $29.99 |
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CROUSE HINDS COOPER CONDULET GS GUA-CS SERIES TYPE GUA HAZARDOUS LOCATION CONDUI $30.00 |
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CROUSE HINDS CONDUIT OUTLET BOX FOR HAZARDOUS LOCATIONS $30.00 |
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NEW KILLARK #VGA-2 3/4″ PENDANT SPLICE BOX FOR HAZARDOUS LOCATIONS $30.00 |
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KILLARK PLUG HAZARDOUS LOCATION **KP-303D45** 30 AMP $30.00 |
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KILLARK EMG1 GUARD GAURD for EM EB EQ SERIES HAZARDOUS LOCATION LIGHTING – NEW/N $30.00 |
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Cooper/Crouse- Hinds CPS14-21 Receptacle Assembly For Hazardous Locations $30.00 |
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☺ *NEW* ALLEN BRADLEY 700-FSK3CU23-EX HAZARDOUS LOCATION TIMER ☻ $29.13 |
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2 CROUSE-HINDS GUAX-47 COUNDULET OUTLET BOX FOR HAZARDOUS LOCATIONS 1 1/4″ $32.00 |
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POTTER BRUMFIELD HAZARDOUS LOCATION RELAY KR-14DGE-24 $32.00 |
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Strate Line Plug For Hazardous Locations EPD-51532 $33.00 |
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Appleton GR Series 1-1/4″ Outlet Box for Hazardous Locations $34.00 |
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NEW – SQUARE D 9007CR53N2 LIMIT SWITCH 10A SER A 600V HAZARDOUS LOCATION SPDT $34.20 |
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Bacharach Combustable Gas Detector for Hazardous Locations 23-4012 $34.99 |
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Outlet Box For Use In Hazardous Locations 93141 $34.99 |
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7 O-Z GEDNEY UNF-100S CONDUIT UNION 1IN MALE TO FEMALE HAZARDOUS LOCATION 55300 $34.99 |
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SIEMENS 51C156H HAZARDOUS LOCATION CONTROL SWITCH w/ 1 SELECTOR SWITCH NEW $35.00 |
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NEW KILLARK #GECLT 1/2″ BOX FOR HAZARDOUS LOCATION $35.00 |
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NEW KILLARK #GEMCA 1/2″ UNILET BOX FOR HAZARDOUS LOCATIONS $35.00 |
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Appleton Mall Iron Device Body for Hazardous Locations 3/4” EFD175-NL-Q $35.00 |
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Appleton Mall Iron Device Body for Hazardous Locations 3/4” EFD175-NL-Q $35.00 |
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USED RED DOT 3/4″ EXT FOR HAZARDOUS LOCATIONS $35.00 |
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NEW RED DOT #EXLB 3/4″ FOR HAZARDOUS LOCATION $35.00 |
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KILLARK EMG1 GUARD GAURD for EM EB EQ SERIES HAZARDOUS LOCATION LIGHTING – NEW/N $35.00 |
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Appleton CPH7933 plug/ hazardous locations 30 amp $35.00 |
