Tag: cooling electronics

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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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

EXAIR High Temperature Cabinet Cooler Systems Provide Durable, Reliable Heat Protection

Published on by Russ BowmanLeave a comment

One of the great things about EXAIR Cabinet Cooler Systems is that the environment in which they’re operated won’t affect their operation, or cooling performance, whatsoever. It’s, of course, important to choose the appropriate NEMA rating. For example, a NEMA 12 (oil tight, dust tight, indoor duty) Cabinet Cooler System will work great on a control panel in a typical factory setting, but if it’s going to be in an area where it could get wet, you’ll want a NEMA 4 (oil tight, dust tight, splash resistant, indoor/outdoor duty) System, and if whatever’s going to get it wet is corrosive in nature, a NEMA 4X (NEMA 4 rated, and made of stainless steel for corrosion resistance) System will be specified. We even make the NEMA 4X Cabinet Coolers in 316SS, if that’s required for corrosion resistance in the area where they’ll be installed.

What if it’s hot – I mean, really hot – in the area? The performance of other methods of cooling such as panel a/c, recirculating fans, or heat pipes is directly affected by the ambient temperature: the higher it gets, the lower their cooling performance. This is not the case with Cabinet Cooler Systems – the only variables to their cooling performance are the pressure and temperature of the compressed air supply. And if the temperature can exceed 125°F (52°C), we can provide High Temperature Cabinet Cooler Systems that are suitable for use in environments where the ambient temperature can be as high as 200°F (93°C). These are available, from stock, in cooling capacities of 1,000 Btu/hr and up.

High Temperature Cabinet Cooler Systems are available, from stock, in cooling capacities of 1,000 Btu/hr and up.

Regardless of where your critical electronics or control panels are located, if you need durable, reliable heat protection for them, EXAIR Cabinet Cooler Systems can provide just that. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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Critical Equipment Needs Reliable Heat Protection

Published on by Russ BowmanLeave a comment

Electricity and water don’t mix. Electrical and electronic components don’t like many contaminants that can be found in industrial settings, either. Exposure to moisture or dirt are surefire ways to “let the smoke out” – it can be just as bad as letting them overheat. Once that’s happened, replacement of the failed components is usually the only option. THAT can get expensive not only in the cost of the component, but also in the downtime waiting for it to come in…which can be a REAL problem if they’re not in stock.

Luckily, there’s no shortage of cooling devices for electrical panels. They all have certain areas/situations where they’ll work just fine, but most have areas/situations that can cause real problems:

Panel air conditioners work a lot like the a/c in your home or office, and if you’ve ever used window a/c units, they work EXACTLY like those. Since they cool the air as they recirculate it through the space, they have filters to catch any particulate. If the panel isn’t sealed tightly, this filter may very well require regular attention. They also use air from the surrounding environment to condense the hot refrigerant gas:

Evaporator: heat from inside air is transferred to a refrigerant, flashing it from liquid to gas.
Compressor: pressurizes low pressure refrigerant gas.
Condenser: transfers heat from hot, high pressure refrigerant gas to outside air.
Expansion valve: lowers pressure (and temperature) of condensed refrigerant, sending it to the evaporator to continue the heat transfer cycle.

If the condenser coils are exposed to contaminants (dust, oil, chemical vapors, etc.), they’ll be subject to fouling & corrosion, making panel air conditioners more prone to failure in more aggressive environments. Also, since they use air from the environment as a heat sink for the refrigerant, their cooling capacity is inversely affected by the ambient temperature.

Heat Pipe systems also use refrigerant, but they don’t have any moving parts to wear. Since they don’t have a compressor or expansion valve, though, they’re incapable of cooling the panel below ambient temperature. The evaporator fins or coils are also still subject to environmental contamination, so they have the same limitations as a panel a/c system…and are further limited in hot spaces.

Panel fans are easily the least expensive cooling method. They’re usually fitted with filters for the outside air that they move through the enclosure. Like heat pipes, they can’t cool the enclosure to a temperature below ambient for the area, and the filters are still subject to clogging from airborne particulate, and since those filters have to be coarse enough for the fan’s cooling air flow, smaller particulate can still make it inside the panel….along with any vapors or gases that could condense, or worse, corrode components inside the panel. If the fan on a home computer can get as dusty as the one in the photo to the left, imagine how much worse the one on a control panel on a factory floor can get.

Liquid to Air coolers use liquid – the most common being chilled water – for cold fluid flow through coils inside the panel to remove heat, which is then transferred to ambient through a refrigerant chiller, or a fan & radiator. The inside coils are subject to fouling and condensation if the panel isn’t sealed tightly, and the refrigerant chiller has the same limitations as a panel a/c unit. If it uses a fan & radiator, it (like panel fans or heat pipes) can’t cool the panel to less than ambient temperature in the area.

EXAIR Cabinet Coolers have no moving parts and use compressed air as the sole cooling medium, so they’re not affected at all by environmental conditions. When they’re properly installed on a sealed enclosure, the only thing the inside of the enclosure ever sees is clean, cold, moisture-free air. Wherever your panel is, and regardless of the environment, EXAIR has a wide selection of cooling capacities, features, and materials of construction. Consider:

  • 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), NEMA 4, or NEMA 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 where space is limited above the panel.
  • 316SS construction for particularly aggressive environments.
  • UL Classified systems for hazardous locations: Our HazLoc systems are approved for Class I Div 1, Class II Div 1 & Class III areas, and ATEX systems are approved for Zones 2 & 22.
Inside, outdoors, high temperature, dirt/dust/humidity, corrosive and classified environments are no problem for EXAIR Cabinet Cooler Systems

If you need heat protection for electrical/electronic panels, EXAIR has solutions. To find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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