Tag: hazardous cooler

NEMA, UL, IP, UL Classified and ATEX ratings

Published on by johnball2014Leave a comment

EXAIR manufactures Cabinet Coolers to keep your electrical components cool inside.  This will help to prevent any costly shutdowns or premature electrical failures due to overheating.  The EXAIR Cabinet Cooler System is a simple device that generates cold air with no moving parts, motors, condensers, or Freon.  They are maintenance-free with a long-life cycle, and installation is quick and easy.  But when mounting the system to your electrical panel, you want to make sure that the Cabinet Cooler meets or exceeds the integrity standard for that environment.  There are standards that categorize electrical panels to protect workers, shield the panel from the environment, and sustain the internal electrical components.   

Electrical panels come in all shapes, sizes, and colors and can be used in a variety of environments, including indoor, outdoor, and even hazardous locations.  Depending on the place and setting, you will need to determine the minimum requirements for the integrity of your electrical panel.  For example, you do not want to use an “indoor only” electrical enclosure for outside areas.  Also, you would not want a standard enclosure to be used in a hazardous area, as it can be very dangerous.  The major organizations that create these electrical standards are NEMA, UL, and IP.  In this blog, I will cover these organizations and how they use the rating system.  

NEMA, or National Electrical Manufacturer Association, and UL, or Underwriters Laboratory, are generally used in North America.  The difference between these two organizations is that the NEMA ratings are self-certifying, while the UL requires testing by qualified inspectors, independent of the manufacturer, for compliance.  They use numbers and, in some instances, letters to indicate the type of environment in which the enclosure can operate. EXAIR Cabinet Cooler Systems are UL listed, so they have been tested and verified.  Currently, there are over 20 different NEMA/UL classifications. 

IP, or Ingress Protection, is an international standard commonly used in Europe and established by the International Electrotechnical Commission, or IEC.  This organization also allows for self-certification.  They use two digits to define levels of integrity for electrical enclosures against intrusion from debris and liquid. The first digit ranges from 0 to 6, which specifies the protection rating from solids.  The second digit, which ranges from 0 to 9, specifies the protection rating for the ingress of water.  The higher the number, the better the protection.  The combination of these two numbers will determine the protection level of the enclosure against dust and water.  There is an equivalence between the NEMA ratings and the IP ratings, but it is up to the preference of the user to verify the protection requirement.   

EXAIR offers three main NEMA types for our Cabinet Cooler Systems, which are the most commonly found within most facilities.  We also offer two additional NEMA ratings that are designated strictly for hazardous locations: UL Classified and ATEX rated.   

From right to left: Small NEMA 12, Large NEMA 12, Large NEMA 4X

NEMA 12 (IP54) Cabinet Coolers are rated for dust and oil tight. NEMA 12 cabinet coolers are ideal for general industrial environments where no liquids or corrosives are present and are located inside the facility.  

NEMA 4 (IP66) Cabinet Coolers are rated for dust tight, oil tight, splash-resistant and indoor/outdoor service. These Cabinet Coolers incorporate a low-pressure relief valve to allow the internal hot air to escape as well as to close and seal when the cooler is not in operation.  This allows this Cabinet Cooler to maintain the integrity of a NEMA 4 enclosure.  

NEMA 4X (IP66) Cabinet Coolers offer the same protection as NEMA 4 but are constructed of stainless steel for food service and corrosive environments.  EXAIR offers both 303SS and 316SS materials.  

HazLoc Cabinet Coolers are designed for hazardous locations and are mounted to NEMA 7, 8, and 9 enclosures.  EXAIR catalogs these Cabinet Coolers as NEMA 4 (IP66) or NEMA 4X (IP66), as mentioned above.  But their registration for UL classified is for Class I, Class II, and Class III hazardous areas, both Div 1 and Div 2.  The reason that they do not match the NEMA rating of the hazardous panels is because they require an X-type or Z-type purge system.  In combination, they will not sacrifice the integrity of the hazardous electrical panels.   

ATEX Cabinet Coolers have similar attributes as HazLoc Cabinet Coolers except this type of registration is popularly used in Europe.  These area classifications fall under the EN/IEC 60079-2 international standard for explosive zones.  It covers three zones in two hazardous areas, gas/liquid and dust.  The ATEX Cabinet Coolers can be used in Zone 2 for gas/liquid and Zone 22 for dust.  Like the HazLoc Cabinet Coolers, to keep their classification, the ATEX Cabinet Coolers require a Zone 2/22 purge system.  The ATEX terminology is as follows:  

Gas – CE EX II 3 G Ex h IIC T3 Gc

Dust – CE EX II 3 D Ex h IIIC 200oC Dc  

EXAIR offers a variety of Cabinet Coolers in stock with different cooling capacities, materials of construction, and operational locations.  We also offer them in 316SS, high temperature versions, and non-hazardous purge.  We do have a Cabinet Cooler System Sizing Guide to help determine the best product for your application or a Cabinet Cooler System Calculator to do it yourself.  For any hazardous location, we do recommend contacting us for clarification.  If you have any questions, an Application Engineer at EXAIR can assist you.    

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Class 2 Div 1, Groups E, F, G Cabinet Coolers

Published on by bdwagesLeave a comment

When it comes to electrical equipment, and in our case electrical cabinets, there are regulations we all must follow for safety concerns from hazardous locations. There are explosion hazards that occur when handling flammable gases, vapors and dust. Hazardous location regulations have been designated from the NEC, CEC, OSHA and the NFPA. There is also a Globally Harmonized System (GHE) that oversees labeling the hazards of products.

In the US the governing body for electrical hazards is the NEC (National Electric Code). In Canada, it is the CEC (Canadian Electric Code). These 2 agencies work very closely together in North America, and have very few differences – the main differences concern how and where signs are posted, not the hazards themselves. Both agencies utilize document NFPA 70 (National Fire Protection Agency) as the primary basis for all electrical hazard information and requirements. The NFPA 70 outlines the different Classes and Divisions.

As we look at our Class II Div 1 groups E,F, and G Cabinet Cooler Systems, where can we actually use them? First, they are to be used in conjunction with a purged and pressurized control, system. They are not a replacement of such systems but, rather, provide cooling for them. To fully understand the environments they can be used, we need to understand the class, division and group meanings so let’s dive in…

Let’s jump right into a brief overview of the Classifications. The classifications offer a precise description of the hazardous material that is (or most likely) in an area, so that the appropriate equipment can be used, and safe installations can occur. Sometimes these classifications are easily recognized, and many times they may take a detailed study of the site. There are 3 categories of hazardous materials which define the type of explosive (or flammable) that is present:

Pixabay Image licensed by Pixabay

Class I = Flammable vapors, gases or liquids – examples would be areas such as Gasoline storage, petroleum Refineries, Dry Cleaning Plants, Fuel Servicing Areas, Spray Finishing areas, etc…

Class II = Combustible dust – examples would be Grain elevators, Flour and feed mills, Metal powders manufacturers, coal plants, etc…

Class III = Ignitable Fibers and flyings – Examples would include sawdust areas, Textile mills, Cotton processing, Cotton Seed Mills, etc..

Now as we dissect this further, we will see that each of these “Classes” are divided into 2 divisions. We many times hear these expressed as Div1 and Div 2. The Divisions tells of the likelihood that a hazardous material may be present in a flammable concentration.

Division 1 = an area where the explosive or flammable vapors, gases, dust, fibers, or liquids (as mentioned in Class definitions) can exist under normal everyday operating conditions.

Division 2 = an area in which the dangerous vapors, gases, dust, fibers, or liquids are NOT likely to be present under normal operations.

After the Classes and the Divisions come the groups.

Class 1 has 4 groups, A-D. These are all gases.

Group A = Acetylene is in the air

Group B = Flammable gases with a Minimum Igniting Current (MIC) less than 0.40 such as hydrogen, butadiene, ethylene oxide, propylene oxide

Group C = Flammable gases with a Minimum Igniting Current (MIC) greater than 0.40 such as ethyl ether, ethylene, acetaldehyde, and cyclopropane

Group D = Flammable gases with a Minimum Igniting Current (MIC) greater than 0.80 such as acetone, ammonia, benzene, butane, ethanol, gasoline, methane, natural gas, naphtha, and propane.

Class II has 3 groups, E,F and G. These are all types of dust

Group E = Combustible Conductive metal dust such as aluminum and magnesium

Group F = Combustible electrically Non-Conductive dust such as coal, carbon, charcoal

Group G = Combustible dusts not included in E or F such as flour, grain, wood, plastic and chemicals.

As we come full circle here looking at our Class II, Div 1, Groups E,F, and G Cabinet Cooler systems, we now understand the following:

  • We know that these systems are perfect for areas that contain combustible dust such as coal dust, flour, grain and feed (Class II)
  • We also know that these will work well in areas where these combustible dusts are constantly present around this Cabinet Cooler (Div 1)
  • Lastly we understand that these are a great fit for all types of dusts, whether conductive or not (Groups E,F,G)

Please feel free to reach out to myself or any of the application engineers for further questions on this or any of our amazing products.

Thank you for stopping by,

Brian Wages

Application Engineer

EXAIR Corporation
Visit us on the Web
Follow me on Twitter

Cover photo by Clker-free-vector-images/29545, licensed by Pixabay

Class III Hazardous Locations Defined

Published on by Tyler DanielLeave a comment

The National Electrical Code (NEC) has a system for classifying areas deemed hazardous due to flammable or combustible materials. When an area is considered classified, extreme caution needs to be taken to ensure nothing within that area provides a possible ignition source. In the US, Underwriter’s Laboratory (UL) provides third-party certification for products that can safely be used in these areas. EXAIR’s newest addition to the longstanding line of Cabinet Coolers was our Hazardous Location Cabinet Cooler. Designed and built with these types of applications in mind, the Hazardous Location Cabinet Cooler has been independently certified by UL for use in Hazardous Locations in Class I Div 1, Groups A, B, C, and D; for use in Class II Div 1, Groups E, F, and G; and also in Class III areas.

Class III areas can often be overlooked as the materials that generally create a Class III area may not always be considered “explosive” by nature. In Class III areas, the risk of combustion occurs due to the presence of ignitable fibers or materials that produce or process combustible flyings. According to the International Electrotechnical Commission (IEC), combustible flyings are defined as solid particles, including fibers, where one dimension is greater than 500µ in size, which can form an explosive mixture with air at standard atmospheric pressure and temperature. These areas are most commonly found within the textile and woodworking industries. The video below, posted to YouTube by News Center Maine, shows just how violent an explosion due to wood fibers can be:

When using a Hazardous Location Cabinet Cooler in a Class III area, it’s important to keep the Cabinet Cooler and immediately surrounding area free of settling debris. Implement a regular inspection, and cleaning procedure if necessary, to ensure that the flyings/textiles don’t accumulate on the Cabinet Cooler.

If you have control panels installed in a hazardous location and are sick of the nonstop maintenance associated with an A/C type system, the Hazardous Location Cabinet Cooler is the right tool for you. Contact an Application Engineer today for help determining the most suitable model for your enclosures.

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD