hazardous location cooler

Hazardous Location Cooler: UL and ATEX!

Published on August 28, 2024 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 August 19, 2024September 25, 2024 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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EXAIR High Temperature Cabinet Cooler Systems Provide Durable, Reliable Heat Protection

Published on July 23, 2024 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.

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 July 12, 2024 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.

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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Tag: hazardous location cooler