The UL Classified Mark

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 III Hazardous Locations Defined

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

Tale Of The Tape: EXAIR Cabinet Cooler Systems vs. Air To Air Coolers

As summer heat continues to rise, so does the volume of inquiries we get for EXAIR Cabinet Cooler Systems.  Many callers want to know what differences they can expect in using our products versus other methods they’re considering…or even using…right now.

One very common method is the use of a fan to draw cooling air into the panel, from the surrounding environment.  This is the simplest, and least expensive option, but it has two main drawbacks:

  • Components inside the panel are now exposed (albeit in a controlled manner) to the very same environmental elements that putting them inside a panel was supposed to protect them from.
  • Since the air surrounding the panel is the cooling medium, the temperature inside the panel will never be lower than the temperature outside the panel.  Fan cooling in hot environments will still allow overheating.
If a computer’s fan in the family room can get this dusty, imagine how much worse a control panel on a factory floor can get.

Two key benefits of EXAIR Cabinet Cooler Systems take direct aim at these drawbacks:

  • Once properly installed on a sealed enclosure, all the air entering the enclosure comes from your compressed air supply.  It’s also been through the Automatic Drain Filter Separator that comes with every EXAIR Cabinet Cooler System, so it’s clean and moisture free.
  • The air generated by the Cabinet Cooler is refrigerated, thanks to the Vortex Tube phenomenon.  It doesn’t matter how hot it is in the area; the air going into the panel is about 50F colder than the compressed air supply.  
Cold air from your compressed air supply, with no openings to the environment, eliminates any environmental effects on cooling capabilities.

Fans are one of the two methods of “air to air” cooling – the other is a closed loop system commonly known as a heat pipe:

*Hot air (inside the panel) causes refrigerant in heat pipe to flash to a gas.
*Cold air (from the environment) causes the refrigerant to condense to a liquid.

While this eliminates the environmental contamination concerns of dirt & humidity, it’s still limited.  Just like fan cooling, this method cannot make it cooler inside the enclosure than the ambient temperature in the surrounding area.

Despite this limitation, heat pipes (first column, below) are generally quite cost effective.  But, considering a total cost of ownership difference of less than $15/year, it’s clear that EXAIR Cabinet Cooler Systems, which aren’t limited by ambient temperature, are a strong contender for favorite selection.

Reliable, durable, and cost effective: the EXAIR Cabinet Cooler System.

EXAIR Cabinet Cooler Systems provide up to 5,600 Btu/hr worth of cooling power.  Regardless of your environment (even Classified/Hazardous locations,) we’ve got a system to keep your electronic and electrical panels safe from heat, humidity, and contamination. If you’d like to discuss enclosure cooling and the benefits of EXAIR Cabinet Cooler Systems, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Computer Fan image courtesy of tico_24 Creative Commons License

Class II Hazardous Areas, Groups E, F and G Explained

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