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

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UL Hazardous Locations Class 2 Division 1

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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UL and EXAIR

UL stands for Underwriter Laboratories, a third-party certification company that’s been around for over a century. UL was founded in 1894 and headquartered in Northbrook, IL. UL is a privately held company with over 14,000 employees and located in over 36 countries*. They certify products with the aim of making the world a safer place for both workers and consumers. Besides testing, they set industry standards to follow when innovating new products. 

EXAIR is UL recognized for our Static Eliminators, Cabinet Cooler Systems and Hazardous Cabinet Cooler Systems. The UL Component Recognized mark below is what you will see on our static eliminated products, including our GEN 4 Power Supplies, GEN 4 Ion Bars and Intellistat Ion Air Gun.

If a product or device carries one of these markings, it’s been evaluated for safety by top professionals in the field.**

This mark is seen least often because it is specifically used on component parts that are part of a larger product system. This component mark is used on a wide range of products, including, but not limited to, power supplies, industrial control equipment and many other products. You will notice the “C” and “US” on either side of the main logo indicating the product has been tested for compliance with both Canadian and US requirements.

EXAIR Cabinet Cooler Systems have the “Listed” UL marking indicating that the product meets the requirements and has passed the testing required to gain the mark for specific characteristics.

EXAIR Cabinet Cooler Systems have the following UL Marking indicating they are UL Listed for both Canada and USA requirements.

If a product or device carries one of these markings, it’s been evaluated for safety by top professionals in the field.

EXAIR has NEMA 12, 4 and 4X Cabinet Cooler Systems and each is UL Listed to maintain NEMA Integrity:

NEMA 12 (IP54) Cabinet Coolers: (Dust tight, oil tight) are ideal for general industrial environments where no liquids or corrosives are present.

NEMA 4 (IP66) Cabinet Coolers: (Dust tight, oil tight, splash resistant, indoor/outdoor service) incorporate a low pressure relief valve for both the vortex tube and cabinet exhaust. This valve closes and seals when the cooler is not in operation.

NEMA 4X (IP66) Cabinet Coolers: (offer the same protection as NEMA 4 but are constructed of stainless steel for food service and corrosive environments.

Note: some cabinet Coolers have thermostats that are UL Listed and Solenoids which are UL Recognized.

Our Hazardous Cabinet Cooling Systems have been tested by UL and meet the stringent UL requirements for service in use in Class I, Group A, B, C and D. Class II, Group E, F and G. and Class III. EXAIR Hazardous Cabinet Coolers have a UL Marking as shown below:

UL Classification for EXAIR Cabinet Cooler Systems

UL’s Marks for our Classification service appear on representative samples of products that UL has evaluated with respect to specific properties, a limited range of hazards or suitability for use under limited or special conditions. In the Classification service, UL determines that a manufacturer has demonstrated the ability to produce a product complying with UL’s requirements with respect to; specific risk, specific conditions, compliance to regulatory codes & standards, and/or other conditions as determined by UL.

All products carrying any UL mark are subjected to UL’s Follow-Up Services program to regularly confirm continued compliance with UL’s requirements.

If you have questions about our UL recognized products, please contact myself or any of our Application Engineers. We have someone here from M-F 7AM-4PM EST.

Jordan Shouse
Application Engineer

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