NEMA Ratings Explained

Published on by jasonkirbyLeave a comment

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

Six Steps to Optimizing:  Making your compressed air system efficient.

Published on by John BallLeave a comment
EXAIR Six Steps To Optimizing Your Compressed Air System

Since air compressors use a lot of electricity to make compressed air, it is important to use the compressed air as efficiently as possible. EXAIR has six simple steps to optimize your compressed air system. Following these steps will help you to cut electrical costs, reduce overhead, and improve your bottom line.

Step 1 – Measure the air consumption to find sources that use a lot of compressed air.  Information is important to diagnose wasteful and problematic areas within your compressed air system. To measure air consumption, flow meters can be used to find the volume or mass of compressed air per unit of time. Flow rates are very useful data points to find problems like leaks, over-use in blow-offs, waste calculations, and comparison analysis.

Step 2 – Find and Fix the Leaks.  One of the largest problems affecting compressed air systems is leaks.  That quiet little hissing sound from the pipe lines is costing your company a lot of money.  A study was conducted by a university to determine the percentage of air leaks in a typical manufacturing plant.  In a poorly maintained system, they found on average that 30% of the compressor capacity is lost through air leaks.  For a 100 hp compressor, you are losing 30 hp into the ambient air.  To put a dollar value on it, a leak that you cannot physically hear can cost you as much as $130/year.  That is just from one inaudible leak in hundreds of feet of compressed air lines.  EXAIR offers an Ultrasonic Leak Detector to find those inaudible leaks to fix.

Step 3 – Upgrade your blow-off devices with engineered products.  Here is a simple example.  A 1/4″ copper tube blow off can consume as much as 33 SCFM (934 SLPM) when supplied with compressed air at 80psig (5.5 bar).  It’ll give you a loud, strong blow off.  If you replace that copper tube with an engineered nozzle, a Model 1100 Super Air Nozzle, you can reduce that flow to just 14 SCFM (396 SLPM) at 80 PSIG (5.5 bar).  If you’re tracking your compressed air usage, you’ll see that replacing just one of them saves you 45,600 Standard Cubic Feet worth of compressed in one 5 day (8 hour a day) work week.  At $0.25 per 1,000 cubic feet of compressed air, that’s a savings of $11.40 per week.  Also, the noise level will be dropped to 74 dBA to make it comfortable when working nearby. 

Step 4 – Turn off your compressed air when not in use.  This step can be done using two simple methods, either by using manual controls such as ball valves or automated controllers such as solenoid valves.  Manual controls are designed for long use and when switching on and off are infrequent. Ball Valves are one of the most commonly used manual shut-offs for compressed air and other fluids.  The solenoid valves can be used for quicker shut-offs.  With the cost of compressed air, every bit counts.  If there are gaps in your operation, they can be triggered with different types of methods.  EXAIR does offer an Electronic Flow Control that has an optical eye and timing sequences to trigger solenoid valves to blow compressed air only when it is required. 

Step 5 – Install Secondary Receiver Tanks.  Compressed air receiver tanks are an integral part of many compressed air distribution systems. Compressed air is stored at a high pressure after drying and filtration. A secondary receiver tank is located on the floor for pneumatic equipment or systems. Think of a receiver tank as a “capacitor”.  It stores the energy within a system to be used in periods of peak demand, helping to maintain a stable compressed air pressure in your system. This improves the overall performance of the compressed air system and helps to prevent pressure swings.  Rather than having to pull from the compressor, a secondary receiver tank can be sized to provide the short-term volume of air for a particular application.

Step 6 – Control the Air Pressure.  People tend to overuse their compressed air for many blow-off applications.  This can create excessive waste, overwork your air compressor, and rob other pneumatic areas.  With Pressure Regulators, they give you control to set the operating pressure.  By simply turning down the air pressure, less compressed air is used.  As an example, a model 1100 Super Air Nozzle uses 14 SCFM (396 SLPM) of compressed air at 80 PSIG (5.5 bar).  If you only need 50 PSIG (3.4 bar) to satisfy the blow-off requirement, then the air flow for the model 1100 drops to 9.5 SCFM (269 SLPM).  You are now able to add that difference of 4.5 SCFM (127 SLPM) back into the compressed air system. If we use the average rate of $0.25/1000 cubic feet to make compressed air, this would be a savings of $135.00/year with an 8-hour shift.  And, if you have many similar blow-off devices, you can see how this can really add up.

It is important to review and monitor your compressed air system.  You can cut your energy consumption, improve efficiency, and save yourself money.  The six steps above will help to diagnose the overall “health” of your compressed air system. EXAIR does carry some of these products to help you measure and analyze.  You may have questions about the Six Steps to Optimize Your Compressed Air System, and an Application Engineer at EXAIR will be happy to help. 

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

Compressed Air Use in the Construction Industry

Published on by Russ BowmanLeave a comment

My drive to work involves passing through a growing neighborhood in the northeast suburbs of Cincinnati, Ohio. Over the past few weeks, I’ve seen a wooded lot get cleared & graded for construction of a new house. A week or so ago, heavy earth-moving equipment was digging the basement foundation…and adding to the traffic as huge dump trucks carried the dirt away. Fast-forward to this morning, when I saw that the 2×4 framing of the walls and the placement of the roof joists were almost complete. The backhoes and dump trucks on the lot have been replaced by a small fleet of carpenter’s work trucks, a ‘porta-potty’ (a real plus, considering the number of workers spending 8–10 hours a day on a site that was the utility equivalent of a primitive campsite)…and an air compressor.

Compressed air has been used in construction since ancient times, when manually operated bellows devices were used to stoke fires to increase the temperature inside furnaces that were used to make metal tools and building materials. The first large scale industrial use of compressed air on a construction project was the building of the Mt. Cenis tunnel in Switzerland. Tunnel construction began in 1857 and was expected to take at least 25 years, with some estimates projecting a timeline of over 70 years. However, technical innovations – like the development of pneumatic drills that replaced steam-operated machinery – allowed them to complete it in only 14 years.

In addition to the pneumatic nail guns and impact drivers being used at the new home site along my daily commute, compressed air has a number of other uses in the construction trades. It’s used for excavation, to power de-watering & sludge pumps, hoists, and even material conveyors. For example, a contractor that was building a large fence on sandy terrain used a Model 150200 2″ Heavy Duty Line Vac to remove sand from the hollow fence posts after using hammer drills (which are also air operated, so you know) to anchor them in place. Another user got a Model 151250 2-1/2 NPT Threaded Heavy Duty Line Vac to remove light dirt & sand from holes they dig to set posts in. Both power their Line Vacs with diesel-fueled 185 CFM tow-behind compressors.

Heavy Duty Line Vac: Hardened Alloy Construction and High Performance

EXAIR Air Knives are also used by construction companies. One of our customers bought a Model 110218 18″ Aluminum Super Air Knife Kit to blow an air curtain onto a conveyor to separate filter fabric out of recycled asphalt. Many lumber & building material manufacturers use them to blow off sawdust and loose debris from plywood, OSB board, roofing shingles, etc.

Top: 108″ Super Air Knife is supported & aimed via an array of Model 9060 Universal Air Knife Mounting Systems.
Bottom: Mounting Systems can be ‘overkill’ for some smaller applications, especially when the user is creative. Yes, that’s a door hinge. No, it wasn’t my idea, but I kind of wish it was.

Another customer uses a Model 6901 Spill Recovery Kit with their Model 6395 55 Gallon Premium High Lift Reversible Drum Vac System for cleaning up spills of hydraulic oil from their equipment at construction job sites. The ability to vacuum it up without dragging an electric cord from a shop vac through the puddles of oil is a real plus for them.

The EXAIR Reversible Drum Vac System converts a drum and dolly into a mobile pumping system.

And back to the Line Vacs, an electrical contractor uses a Model 6086 3″ Aluminum Line Vac to pull wire through stretches of underground conduit that are too long for standard fish tapes. They can pull the fish line through 120 feet of conduit in about 30 seconds. The Line Vac also removes any debris that might have accumulated inside the conduit between installation and wire pulling.

If you’re in the construction industry – or any industry, really – and would like to discuss a potential application for engineered compressed air products, give me a call.

Russ Bowman, CCASS

Application Engineer
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Keep Your EXAIR Products Maintenance-Free with Refrigerant Compressed Air Dryers

Published on by Tyler Daniel2 Comments

When we talk with customers about their EXAIR Products, we also discuss the quality of their compressed air. Many of our products have no moving parts and are considered maintenance-free when supplied with clean, dry compressed air. One of the most critical aspects of a compressed air distribution system is the dryer.

No matter where you are in the world, the atmospheric air will contain water vapor. Even in the driest place in the world, McMurdo Dry Valley in Antartica, there is some moisture in the air. As this air cools to the saturation point, also known as dew point, the vapor will condense into liquid water. The amount of this moisture will vary depending on both the ambient temperature and the relative humidity. According to the Compressed Air Challenge, a general rule of thumb is that the amount of moisture air can hold in a saturated condition will double for every increase of 20°F. In regions or periods of warmer temperatures, this poses an even greater problem. Some problems that can be associated with moisture-laden compressed air include:

  • Increased wear of moving parts due to removal of lubrication.
  • Formation of rust in piping and equipment.
  • It can affect the color, adherence, and finish of paint that is applied using compressed air.
  • Jeopardizes processes that are dependent upon pneumatic controls. A malfunction due to rust, scale, or clogged orifices can damage products or cause costly shutdowns.
  • In colder temperatures, the moisture can freeze in the control lines.

In order to remove moisture from the air after compression, a dryer must be installed at the outlet of the compressor. It is recommended to dry the compressed air to a dew point at least 18°F below the lowest ambient temperature to which the distribution system or end use is exposed. A dew point of 35-38°F is often sufficient and can be achieved by a refrigerated dryer (Best Practices for Compressed Air Systems). This makes the refrigerant dryer the most commonly used type in the industry.

A refrigerant dryer works by cooling the warm air that comes out of the compressor to 35-40°F. As the temperature decreases, moisture condenses and is removed from the compressed air supply. It’s then reheated to around ambient air temperatures (this helps to prevent condensation on the outside of distribution piping) and sent out to the distribution system.

With your air clean and dry at the point of use, you’re making sure you get the most lifespan out of EXAIR’s point-of-use Intelligent Compressed Air Products.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

X: @EXAIR_TD