Tag: high temperature

What Is A NEMA Rating?

Published on by Brian FarnoLeave a comment

With the Summer heat upon us here in Ohio the inquiries for our Cabinet Cooler Systems are increasing by the day.  A question we always ask customers with Cabinet Cooler Sizing Guides is, “What NEMA Type is your enclosure?”  There are quite a few times where no one truly knows what a NEMA rating is. So what exactly is a NEMA rating?

NEMA is the National Electrical Manufacturers Association, one of the many standards they publish is the NEMA rating standard for electrical enclosures up to 1000 Volts.  This standard is where NEMA Types such as 12, 4, and 4X come from (you will also see an international standard reference as “IP”, more on that later).  It categorizes the enclosures by their ability to protect the internal components from things such as corrosion, dust, oil, even external air quality. These standards are reviewed every five years and the last review was done in 2013.  The reviews are generally based on improving safety, clarity of the standard, and testing methods.

So what NEMA ratings does EXAIR offer?  For our Cabinet Cooler Systems, EXAIR offers three very common NEMA types to try an offer a selection to fit the needs that we most commonly encounter.  The NEMA types and their descriptions are below.   For a full list of the Non-hazardous location NEMA enclosure types, click on this link.

EXAIR NEMA 12 Cabinet Cooler System w/ Side Mount Kit

Type 12 (IP54): General purpose, indoor use.  Protects against falling dirt and circulating dust, lint, fibers, and flyings.  Protects against ingress of dripping and splashing water. Rust-resistant Type 12 enclosures do not include knockouts.

 

EXAIR NEMA Type 4 Cabinet Cooler System
EXAIR NEMA Type 4 Cabinet Cooler System

Types 4, 4X (IP66): Water-tight, dust-tight, sleet-resistant.  Resistant to windblown dust.  Indoor or outdoor use.  Also provides protection against splashing and hose-directed water.  The “X” designation indicates corrosion-resistance.

EXAIR's High Temp Cabinet Cooler Systems

The EXAIR Cabinet Cooler Systems also reference an equivalent IEC (International Electrotechnical Commission), IP code.   This is a code from the IEC system which specifies the ingress protection which classifies and rates the degree of protection provided against intrusion (body parts such as hands and fingers), dust, accidental contact, and water by mechanical casings and electrical enclosures. They are a two digit number that represents the level of protection against physical objects and he ingress of water.   Coorelation between NEMA ratings and IP codes is not always possible.  EXAIR has ensured that we also meet the equivalent IP codes shown in the NEMA descriptions above.

If you have a hot enclosure and you are not sure how much cooling is needed or what the NEMA type is, contact us.  We will gladly help you gather the information needed to calculate the heat load requirements and help determine the correct NEMA rating.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

Can An EXAIR Cabinet Cooler Work With My Enclosure?

Published on by Lee EvansLeave a comment

NEMA 4X Cabinet Dimensions

As I scanned through my emails this morning in search for a Cabinet Cooler Sizing Guide sent to me back in June (some changes were made by the end user and I wanted to reference the original heat load), I noticed the large number of sizing requests typical of summer months.  When I clicked back to my inbox I saw four more Cabinet Cooler sizing requests awaiting me from different corners of the globe.

One that stood out to me was in a particularly hot environment (Approximately 180 degrees Fahrenheit), and needed NEMA 4X protection.  The end user was kind enough to send a sketch of the enclosure they plan to use, and needed to know if an EXAIR NEMA 4X Cabinet Cooler could work for their application.

Fortunately for the end user, our Cabinet Coolers are suitable for many types of enclosures, and we have a staff of Application Engineers on hand to sort through any abnormalities or questions which may arise.  So, we are able to say with certainty that our Cabinet Cooler can work in their application.

Another fortunate feature for this end user is that EXAIR manufactures High Temperature Cabinet Coolers available from stock, and suitable for temperatures up to 200 degrees F.  These high temp systems are perfect for metallurgical plants, use near ovens or furnaces, and for applications with higher than normal compressed air temperature.

If the specifics of your application raise any doubt about integrating an EXAIR Cabinet Cooler, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

 

 

Adjustable Air Amplifier Removes Heat, Protects Thermocouple

Published on by Neal RakerLeave a comment

I was working with a customer recently who had a fairly interesting application that I’d like to share with you. The customer operates a steel furnace and they have an automatic, liquid steel temperature probe that does not have sufficient time to cool down before they take another temperature measurement which should be a minimum of 5 minutes.

The probe consists of a 6 foot long, ¾” pipe, attached to the end of a 12 foot long beam. The beam lowers the pipe with the probe attached into the steel bath to take the temperature (see sketch below). The pipe is covered with a consumable, cardboard type of tube (pictured above) which is the thermocouple.  A contact block with wiring inside the pipe connects to the thermocouple. This contact block becomes heat damaged because the pipe does not have enough time to cool between temperature measurements.

steel temperature

The customer was originally thinking about using a Super Air Knife to cool the probe and pipe between temperature measurements. After discussing options, the customer took our advice and went with (2) of our 2” Stainless Steel Adjustable Air Amplifiers (model 6042) instead. The Air Amplifiers are able to be mounted at the “parked” position of the pipe / probe and actuated to blow down the pipe and thermocouple length-wise during this time.

The high velocity airflow was able to carry enough heat out of the assembly between temperature measurements that the contact block was no longer becoming overheated and damaged as it was before. We decided to suggest this option to the customer because the air usage for this option was less than that of a 60” long Air Knife and the Stainless Adjustable Air Amplifier has temperature rating of 400°F which was easily able to withstand the heat in the application.

Neal Raker, Application Engineer
nealraker@exair.com

 

 

Insulating a Cabinet Can Help to Reduce Overall Heat Load

Published on by Neal RakerLeave a comment

Insulated Cabinet  Insulated Cabinet2

I was working with a customer the other day who had a control panel located in a very hot environment next to a steam turbine in a power plant. The panel already had a Cabinet Cooler System working to keep the internal space cooled. However, due to some faulty temperature data about the surrounding environment, the customer had underestimated the heat load required in the application. As a result, his control cabinet was running a little higher than he wanted it to in terms of temperature. His Target was 95°F but he was running a solid 105°F inside the cabinet.

After we discussed the application a bit further and he sent some photos of the Cabinet, I learned that there was a rather large, hot turbine, just inches away from this panel. I also determined that the customer had installed our Cabinet Cooler on the top of the panel and was feeding it with proper compressed air to allow it to work at full capacity.

This is where some thinking about other strategies when considering how to reduce heat load on a cabinet come into play. Namely, passive methods of adding insulation to the exterior of the panel as well as employing heat shields between the heat source and the cabinet. Both methods are good ways to passively reduce the amount of heat load that needs to be delivered from a Cabinet Cooler to the cabinet.

In this application, the customer not only insulated his whole panel, but also the in-coming compressed air line to keep the heat from the turbine from sinking in through the walls of the cabinet and the compressed air pipe. After he made the suggested changes, the customer was able to reduce his cabinet temperature by the needed 10°F to keep a safe, 95°F inside the cabinet.

Neal Raker, Application Engineer
nealraker@exair.com