NEMA Ratings Explained

NEMA ratings serve as important standards that delineate the specific environments suitable for electrical enclosures. Established by the National Electrical Manufacturers Association, this rating system indicates the capacity of a fixed enclosure to endure various environmental conditions. Below are some of the reasons why NEMA ratings are used for rating enclosures.

Environmental Protection– NEMA ratings serve as a benchmark for the level of protection that electrical enclosures offer against various environmental elements, including dust, moisture, chemicals, and corrosion.

Safety – Ensuring the safety of personnel and preventing accidents related to enclosures is of the utmost importance. By choosing the correct NEMA-rated enclosure, the risks associated with electric shock and exposure to hazardous materials can be significantly reduced or entirely avoided.

Equipment Performance– To ensure optimal performance of electrical equipment, it is essential to adhere to specific environmental requirements tailored to the equipment’s needs. The ratings associated with the equipment will guide you in selecting appropriate enclosures that offer adequate protection against temperature extremes, humidity, and excessive vibration.

Compliance and Regulations– NEMA ratings are established by regulatory bodies and industry standards to ensure that electrical installations adhere to essential requirements. Adhering to these ratings minimizes the risk of non-compliance and the potential legal ramifications that may arise from it.

Equipment Durability and Reliability– Electrical enclosures designed with the appropriate NEMA ratings provide enhanced durability and reliability by safeguarding internal components from environmental influences. This protection not only prolongs the equipment’s lifespan but also minimizes maintenance requirements and boosts overall system performance.

NEMA 12 Cabinet Cooler Systems are oil-tight, dust-tight, and rated for indoor duty. They can also be installed on the wall of an enclosure (instead of the top) with a Side Mount Kit.

EXAIR Cabinet Cooler NEMA Ratings:

NEMA 12 enclosures are designed primarily for indoor use in industrial, manufacturing, and machining environments. These robust metal enclosures provide effective protection against dust, dirt, and non-corrosive liquids, including oils and lubricants.

NEMA 4 rating signifies that an electrical enclosure is designed to withstand exposure to wind-driven dust and rain, splashing water, and water from hoses, while also resisting damage from ice accumulation. This rating makes the enclosure suitable for both indoor and outdoor applications, ensuring robust protection against various environmental conditions.

NEMA 4X rating indicates that an electrical enclosure is suitable for both indoor and outdoor applications, providing protection against wind-driven dust, rain, splashes, and hose-directed water, as well as resistance to corrosion. The inclusion of the “X” signifies enhanced corrosion protection, making these enclosures ideal for challenging environments such as marine locations and chemical processing facilities.

If you have questions about NEMA Ratings, or anything regarding EXAIR and our products, please do not hesitate to reach out.

Jason Kirby
Application Engineer
Email: jasonkirby@exair.com
Twitter: @EXAIR_jk

Hazardous Location Cooler: UL and ATEX!

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

Send me an Email 

Find us on the Web 

 Like us on Facebook

Twitter: @EXAIR_JS

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

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
Visit us on the Web
Follow me on Twitter
Like us on Facebook

Critical Equipment Needs Reliable Heat Protection

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
Visit us on the Web
Follow me on Twitter
Like us on Facebook