Tag: hazardous location

Hazardous Location Cabinet Cooler Systems “Make Things Better”

Published on by Russ BowmanLeave a comment

In a previous arc in my career path, I worked on, and then built, and then sold industrial pumps, so I’ve been in my fair share of chemical plants. Did you ever wonder what all these places make? A decent number of them make what are called “intermediates”. These are compounds, solutions, & substances that aren’t found in stores, but go into almost all of the goods that ARE found in stores. One such company used to make commercials that explained it nicely:

I recently had the pleasure of assisting a caller from a company like this, who wanted to install three of our Hazardous Location Cabinet Cooler Systems in their facility. This particular company doesn’t make anything shown in the commercial above; they make intermediates for agricultural use (to paraphrase the commercial, “they don’t make fertilizer; they make fertilizer better”). As is the case in MANY chemical plants, a good portion of their real estate is classified as hazardous area (as defined by regulatory oversight agencies) AND subject to exposure to some fairly corrosive chemicals. Now, these places all go to great lengths to ensure safety for personnel AND equipment, through compliance AND design. So, when they needed to add durable & reliable heat protection to their electrical panels, they called EXAIR.

This was a pretty easy application, as the engineer I spoke to had gotten the internal heat loads from the equipment supplier, and already knew that 316SS construction was needed for the corrosive elements the equipment could be exposed to. The panel was in a Class I Div 2 area (flammable gasses or vapors may be present in the event of an accident or during unusual operating conditions). After calculating the external heat load, we specified a Model HZ4725SS-316 NEMA 4X (316SS Construction) Hazardous Location Cabinet Cooler System, rated for 1,700 Btu/hr, and Model 902021 24VDC HazLoc Solenoid Valve. These panels came equipped with temperature monitors that they could wire our valves into, otherwise we’d have supplied Thermostat Controlled systems.

EXAIR HazLoc Cabinet Cooler Systems are rated for Class I Div 1 & 2, Class II Div 1 & 2, and Class III environments.

EXAIR Cabinet Cooler Systems are available, from stock, to suit most any electric/electronic panel heat protection need:

  • Cooling capacities from 275 to 5,600 Btu/hr. Call me if your heat load is outside this range…we can look at customized solutions too.
  • NEMA 12 (IP54), 4, or 4X (IP66) ratings.
  • Thermostat Control – Standard, or Electronic Temperature Control.
  • Non-Hazardous Purge for contaminant exclusion on less-than-ideally sealed enclosures.
  • High Temperature models for ambient temperatures from 125°F (52°C) to 200°F (93°C).
  • Side Mount Kits when space is limited above the panel.
  • 316SS construction for particularly aggressive environments.
  • UL Classified for hazardous locations, just like the one I wrote about above.

If you’d like to find out how easy it is to provide durable and reliable heat protection for your electrical panels, give me a call.

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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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
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Cover photo by Clker-free-vector-images/29545, licensed by Pixabay

The UL Classified Mark

Published on by codybiehleLeave a comment

Safety, it’s a word that gets tossed around in both the work place and in your daily life.  From the beginning of time, people have been injuring themselves at work and at home. Today’s well known phrases “Hey watch this” or “Hold my Beer” became a popular way to say I am about to do something crazy and stupid and I know it. As someone who enjoys the outdoors and the thrills of extreme sports, I can attest from both personal experience and the experiences of those around me that people don’t make smart decisions. At a young age I had a laundry list of injuries longer than most people 10 years older than me. But even in the craziest of my stunts (i.e. running an 18’ waterfall in a kayak) there is a level of safety that is put into place. That safety can come from the practice it takes to develop higher skill (experience) or from the knowledge of experts around you. 

Companies have been trying to figure out ways to make offices and manufacturing plants a zero-incident environment for a long time. A lot of safety departments call this journey the Road to Zero and track each incident closely. Aside from policies and equipment modifications there are consulting and certification companies that focus solely on the safety of products used in manufacturing and production plants. One of the more prominent companies in the U.S. is UL or Underwriters Laboratories; this company was founded by an electrical engineer named William Henry Merrill in 1894. In 1893 an insurance company hired Merrill to perform a risk assessment on new potential clients, George Westinghouse and Nikola Tesla. This led him to realize the potential for an agency to test and set standards for product safety.

One example of a sought after and critical accreditation is the UL Classified Mark. The UL Classified certification means that the product has been evaluated, tested and passed the test for being safe when installed within classified areas. This includes a large range of hazardous locations which according to OSHA is defined as an explosive atmosphere due to the presence of flammable fluids (Class 1), combustible dusts (Class 2), or ignitable fibers and flyings (Class 3). These areas include everything from chemical plants to the food industry.

EXAIR’s Hazardous Location Cabinet Cooler

EXAIR has a Cabinet Cooler that can be used in these Hazardous Locations and earned the UL Classified Mark. The Hazardous Location Cabinet Cooler Systems are designed to be used with purged and pressurized systems in the following locations:

Class I Div 1, Groups A, B, C, and D
Class II Div 1, Groups E, F, and G
Class III

This means that the Hazardous Location Cabinet Coolers can be used in areas with explosive gas and vapors, combustible dusts, or ignitable fibers. 

If you have any questions about compressed air systems or want more information on any of EXAIR’s products, give us a call, we have a team of Application Engineers ready to answer your questions and recommend a solution for your applications.

Cody Biehle
Application Engineer
EXAIR Corporation
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Class II Hazardous Areas, Groups E, F and G Explained

Published on by johnball2014Leave a comment

The National Electrical Code, or NEC, classifies hazardous areas into three different categories; Class I, Class II, and Class III.  To use equipment in or around these types of areas, caution has to be taken to not cause an explosion or fire.  In the U.S., the Underwriter’s Laboratory, UL, can certify products that can be used safely in these hazardous areas.  EXAIR received our UL Classification for our HazLoc Cabinet Cooler® Systems.  Under certain guidelines, the HazLoc Cabinet Coolers can be used in Class I areas for gases and vapors, Class II areas for flammable dust, and Class III areas for ignitable fibers and flyings.  In this blog, I will cover the Class II hazardous areas.

First, HazLoc Cabinet Coolers are designed to keep electrical components cool during summer months and higher ambient conditions.  They are powered by an EXAIR Vortex Tube which only uses compressed air to generate cold air.  They do not have any moving parts, refrigerant, or refrigerant compressors to fail.  These simple, but effective, cooling devices can be used in the toughest of environments.  With the Vortex Tube as the “engine”, the reliability of the EXAIR HazLoc Cabinet Cooler is unmatched.  It is an easy choice for cooling electrical panels and reduce premature shutdowns.

For a fire to occur, we only need three things as described by the fire triangle; oxygen, fuel, and an ignition source.  For an explosion, we need two other conditions, dust concentration and confinement.  For a Class II area, the fuel is combustible dusts.  “Combustible dusts are fine particles that present an explosion hazard when suspended in air under certain conditions.”1  By NEC standards, dust is categorized into three different groups.  Group E is for metal dust.  This will include aluminum and magnesium dust.   Group F is for carbonaceous dust like charcoal, coal, and carbon black.  And Group G is for non-conductive dust like flour, grain, and plastic.  These fine particles can float and collect on equipment in the surrounding areas.  This collection of material can ignite and cause a fire from a spark or a heat source.  If they are contained like within a panel, then there is a possibility of an explosion.

The ignition source (the second leg of the fire triangle above) is generally from electrical equipment, heat, and static.  Arcs and sparks from motors, contacts, and switches can ignite Class II materials; as well as, high temperatures from equipment.  NEC and UL segregate this hazardous location into two divisions.  Class II Division 1 is in an area where dust material is handled, manufactured, or used.  Class II Division 2 is where the dust material is stored or handled other than in the process of manufacturing.  In both divisions, it is important to protect your electrical systems from these particles “floating” in the surrounding air.

The EXAIR HazLoc Cabinet Cooler Systems are designed to keep your electrical panels cool within hazardous areas like Class II above.  Because system shutdowns from electrical components overheating are costly and potentially dangerous, you can install a HazLoc Cabinet Cooler System without sacrificing your panel’s integrity.  If you would like to discuss in more detail about the different types of EXAIR HazLoc Cabinet Coolers, an Application Engineer at EXAIR will be happy to help you.

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

 

Note 1: Osha.gov publication

Photo: Inflammable Sign Hazardous Symbol European by Clker-Free-Vector-Images.  Pixabay License