Tag: Enclosure air conditioner

Hazardous Location Cooler: UL and ATEX!

Published on by Jordan T ShouseLeave a comment

EXAIR currently offers TWO styles of cabinet coolers designed and certified for classified areas. Both UL Classified and ATEX!

Hazardous locations are a tricky opponent for electrical panels and controls. To safely be in a HAZLOC, they either have to be rated for that environment or they need to be enclosed in a Cabinet that is purged and pressurized to keep any explosive gases, fumes, or dust out of the Cabinet. This is no new thing, however, as the Industrial revolution 4.0 continues to grow and progress, products are continually being added to HAZLOC areas. For example, robotic controls, analyzers, motors and switch gears now use electronic accessories to meet the needs for speed, process control and energy efficiency, which often renders the equipment unsuitable for use in hazardous locations.  While the demand for these new devices continues to grow, not all of these items are able to be made intrinsically safe. And the items that are not will need to be enclosed in a cabinet where heat will build, and you need to manage that heat load while retaining the positive pressure purge and pressurization.

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 classification 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 to 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.    

 Jordan Shouse

Application Engineer

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UL Hazardous Class 1, Div 1, Groups A,B,C and D

Published on by Jordan T ShouseLeave a comment

EXAIR’s HazLoc Cabinet Cooler Systems have been set apart from the competition by achieving the UL classified designation for Div 1 environments. Thermostatically controlled systems are recommended for the highest efficiency and include UL-listed solenoids, also for hazardous environments. EXAIR Cabinet Cooller systems will install on your purged enclosure in minutes, require little to no maintenance and operate under the roughest of industrial conditions. If you require low cost, ease of use and reliability, a HazLoc Cabinet Cooler system will meet your needs.

 In the United States, the National Electrical Code (NEC) defines these areas in a system of Classes, Divisions, and Groups, depending on the nature of the material that presents the hazard (Class), whether it normally exists or if it’s just possible in abnormal situations (Division), and the specific type of the subject material (Group). Today’s blog is all about what would classify an area as Class I, Division 1, and which Group the specific hazardous material falls under.

A Class I location means that the hazard is a flammable gas or vapor which is present in the area in a high enough concentration to be considered ignitable. These were the locations that we were required to use non-sparking tools within, and for good reason. Some examples of Class I locations are:

  • Petroleum refineries
  • Gasoline storage or dispensing areas
  • Aircraft hangars and fueling stations
  • Spray finishing rooms or booths

Division 1 means that the flammable gas or vapor that makes the area a Class I location is present in the atmosphere during normal operating conditions and/or when the gas or vapor is released to the atmosphere during maintenance or repair work. These gases & vapors aren’t present in ALL areas of the above-listed Class I examples during normal operation, so only the areas where they ARE present during normal operations would be defined as Division 1. For example:

  • Areas where a gasoline tank (in a refinery or gasoline storage/dispensing station, for example) is vented to the atmosphere are Class I Division 1, because the vapor coming out of the vent is doing so by design…you can’t pump a liquid into a non-vented tank.
  • Only the parts of an aircraft hangar where fuel is actually being handled are Division 1. That wouldn’t necessarily apply to a stock or communications room in the hangar, though.
  • The interior of a paint booth is Division 1 because the spray is volatile, as is the immediate vicinity adjacent to an open spray booth.

Class I designation is further divided into four groups, based on two specific characteristics of the gas or vapor that express how easy it is to cause (or how hard it is to prevent) an explosive hazard:

  • Maximum Experimental Safe Gap (MESG) – The gas is put in the interior chamber of a vessel with an adjustable gap that leads to the outer chamber. MESG is the largest gap between the chambers that will prevent ignition of the gas.
  • Minimum Igniting Current (MIC) ratio. This is the ratio of the minimum current from an inductive spark required to ignite the gas, divided by the minimum current from an inductive spark that will ignite methane under the same conditions.
  • Group A: Acetylene
    • MESG = 0.25 mm
    • MIC ratio = 0.017
  • Group B: Hydrogen, butanedione, ethylene oxide, Propylene oxide, and acrolein
    • MESG <0.45mm (except acetylene)
    • MIC ratio <0.4 (except acetylene)
  • Group C: Ethylene, cyclopropane and ethyl ether
    • MESG = 0.45mm to 0.75mm
    • MIC ratio = 0.4 – 0.8
  • Group D: Acetone, ammonia, benzene, butane, ethanol, gasoline, hexanes, methane, methanol, methane, naphtha, natural gas, propane and toluene
    • MESG >0.75mm
    • MIC ratio >0.8

EXAIR HazLoc Cabinet Cooler Systems are engineered and approved for use on electrical enclosures in these areas, as well as Class II and Class III. Our ATEX Cabinet Cooler Systems are compliant with the European Union’s ATEX Directive (Zones 2 and 22).

Both the HazLoc (left) and ATEX (right) Cabinet Cooler Systems are available from stock in NEMA 4 and NEMA 4X ratings.

Wherever the panel you need cooling for is located, we’ve very likely got a reliable and safe solution. If you’d like to find out more, give me a call.

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS

UL Hazardous Locations Class 2 Division 1

Published on by Jordan T ShouseLeave a comment

Per the National Electrical Code (NEC) there are (3) classifications for areas that are defined as hazardous.  They are Class I (gases & vapors), Class II (flammable dust) & Class III (fibers). The focus of today’s Blog is on Class II locations.

Class II locations are those that are hazardous because of the presence of combustible dust. Note that the dust must be present in sufficient quantities for a fire or explosion hazard to exist. The fact that there is some combustible dust present does not mean a Class II hazardous location exists. Dust is defined as a combustible material that must exist as a finely divided solid of 420 microns (0.420 mm) or less. This will allow the dust to pass through a No. 40 sieve.  Just as in Class I, Division 1 and 2, the subdivision of Class II into Divisions 1 and 2 identifies the likelihood that there is an explosion hazard.

Division 1 locations are defined as an area where the amount of combustible dust is either suspended in the air or accumulated on surfaces in a sufficient concentration to allow for ignition.  The ignition could be caused by a failure or malfunction of the equipment in the classified area.  Group E & F dust (see chart below) is considered conductive and could penetrate into electrical equipment such as electric motors, control panels, electrical panels, etc., and cause an electrical failure.

Chart1

Group E dusts are metal dusts, such as aluminum and magnesium. In addition to being highly abrasive, and likely to cause overheating of motor bearings if it gets into them. Group E dusts are also electrically conductive and if they are allowed to enter an enclosure, can cause an electrical failure.

Chart2

Group F dusts are carbonaceous. The primary dust in this group is coal dust. Coal dust has a lower ignition temperature than those in Group E. While Group F dust has a higher thermal insulating value than the layer of Group E.  Therefore Group F requires more control of the temperature on the surfaces that the dust settles on. Group E dusts are semi-conductive, however if the voltages are 600 volts or less it is not generally considered a factor.

Chart3

Group G dusts include plastic dust, most chemical dust and food-grain dust. They are not electrically conductive. Generally, these dusts have the highest thermal insulating characteristics and the lowest ignition temperatures. Therefore, the equipment used in Group G areas must have the lowest surface temperatures to prevent ignition of a layer.

Chart4

Lastly, equipment rated for use in Classified Environments has a rating called the Temperature Code or “T-Code”.  This is the temperature or rather, temperature range that the rated device will operate normally and/or in a failed or failing state.  Consider something as common as a light fixture, electric motors, etc., as they could become hot enough to cause ignition depending on the type of dust in the area.  So be sure to check the “T-Codes” for every piece of equipment that will be used within a Classified Environment.

Chart5

When you are looking for expert advice on Hazardous Location Cabinet Coolers or safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you.

Jordan Shouse
Application Engineer

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Twitter: @EXAIR_JS

Cooling Electrical Panels: Freon-based A/C or Cabinet Coolers?

Published on by John BallLeave a comment

These hot summer months can bring some elevated temperatures within electric control panels.  With Freon based coolers, higher ambient conditions make them less efficient; and opening the electrical panel to have a fan blow inside creates a dangerous electrical hazard.  For every 10oC rise above the operational temperature, the life of an electrical component is cut in half.  To reduce loss in productivity and premature equipment failures, it is important to keep your electrical mechanisms cool.  The EXAIR Cabinet Coolers are designed to do just that.

We receive many questions when it comes to panel cooling as the Vortex technology is relatively new in this area.  The main question is the comparison between the Cabinet Cooler System and the Freon-based A/C panel units.  In short, the Cabinet Coolers have no moving parts to wear, do not use Freon, and require little maintenance.  But they do require clean compressed air to operate.  The Freon-based A/C units do not use compressed air, and only need electricity to operate.  In this blog, I will cover a term to consider: Total Cost of Ownership.

What do I mean by Total Cost of Ownership?  I mean that you not only take into account energy use, but also other, very real issues about owning a system.  There are some significant financial impacts on the bottom line when one considers the need for using the electrical or electronic panel coolers.

Initial Unit Cost – The initial cost to acquire a vortex style Cabinet Cooler is between 1/3 and ¼ the cost to acquire a Freon-based air conditioner system. And if we consider that a typical life span for a Freon-based cooling solution is 5 years, then the yearly cost is $500.00/year.  An EXAIR Cabinet Cooler System, by comparison, will have a 20-year life span as there are no moving parts to wear out. That makes for a yearly cost of $36.45 / year. Quite a large difference between the two. Also, note that over the 20-year life of an EXAIR Cabinet Cooler, the Freon unit will have to be replaced 4 times. We’re not taking that into account in our calculations, but assuming the cost remains the same over that time.

Installation – Because it is so easy to install an EXAIR Cabinet Cooler system, the estimated time to install is only 1 hour. One small hole to mount the unit on the top of the panel and another hole to route the thermostat to the solenoid.  With a small amount of plumbing for the compressed air and cold air distribution kit, the extent of the installation is complete. Compare that to the estimated 3-hour minimum time in order to install a Freon-based solution. With this unit, it will come with very large cut-outs on the panels to allow for the airflow to process through.

Maintenance – In this comparison, we are stating that there are no maintenance or downtime requirements for EXAIR Cabinet Cooler systems. This is another area where the EXAIR Cabinet Coolers really pull ahead of the Freon-based solutions. Yes, there is some small amount of annual filter maintenance for the compressed air supply, but a quick washing and re-installation of the sintered bronze element, and you are back in business in a very short time.  The Freon-based solution, by comparison, will require a minimum of 4 hours per year (one time per quarter) for charging with Freon (due to expected leaks), cleaning and replacing filters, washing the condenser, and performing compressor checks. At an estimated $80.00/hour, that is $320.00 per year for labor plus any parts. 

Operations – Here we can compare energy use.  If we use a simple estimate for the cost of compressed air at $ .25 / 1000 Standard Cubic Feet, then over the course of a year of operation, a vortex style cooling solution will run about $338.00 / year to operate. For a comparable Freon-based cooling system, it will be about $56.38 / year to operate.  But with a Freon-based system, it will need to be over-sized for ambient conditions over 95oF (35oC), which will make this more comparable. 

Electrical shutdowns are expensive and annoying, and if you do not maintain the Freon-based systems regularly, the shutdowns can occur often.  In showing the Total Cost of Ownership, it shows that the EXAIR Cabinet Coolers are a great purchase.  With no moving parts, Freon, or costly preventative maintenance needed, they can operate for decades to keep your electronics cool.  For our U.S. and Canadian customers, we are offering a promotion.  You will receive an AC Sensor, a $76.00 value, for free as a promotional item from now until the end of August 2024 with a qualified purchase.  How can you not give them a try?  If you have any questions about Cabinet Coolers or the Sizing Guide, you can contact an Application Engineer at EXAIR.  We will be happy to help you.  Remember whenever you make a purchase, you should always look at the Total Cost of Ownership to get the entire story. 

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