Calculate Heat Loads from the Sun for Outdoor Control Panels

I am always happy to see the sun rise each morning. But, electrical panels that are exposed to the sun are not.  Solar heat adds significant BTU’s to the overall heat load in an electrical panel.

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A customer had a VFD to control a 300HP blower motor for a dust collection system. The VFD was getting an over-temp error and shutting down the system.  He contacted EXAIR to get a Cabinet Cooler to keep the VFD cool.  We went through our normal questions to determine the heat load, i.e. the size of the cabinet, the temperature inside, the temperature outside, the maximum external temperature and the desired temperature.  As we went through the questions, he stated that the cabinet was located outside.  This is not an issue for our Cabinet Coolers as EXAIR has NEMA 4 and 4X (IP66) Cabinet Coolers.  It did stem another question; was it under cover?  He mentioned that it was not.

NEMA 4 Cabinet Cooler
NEMA 4 Cabinet Cooler

Generally in calculating cooling capacities with our Cabinet Coolers, we size the units by adding the ambient heat load and the electrical heat load. With the panel exposed to the sun, this adds another component to the total heat load.  To get an estimation on the amount of solar heat, color becomes a big factor as the darker colors will draw more heat.  Here is a good approximation to follow:

Solar heating by color
Solar heating by color

In this application, the customer had a gray panel, a common color. With an exposed surface area of 16 ft^2 (1.47 M^2), we would have to increase the heat load by 16 ft^2 * 7 Watts/ft^2 = 112 Watts.  This equates to 112 Watts * 3.41 BTU/hr/Watt = 382 BTU/hr of added heat.  (Or 112 Watts * 0.86 Kcal/hr/Watts = 96 Kcal/hr).

If an electrical panel is outside and cannot be shaded from the sun, we can still protect the sensitive components inside.  With the proper sized Cabinet Cooler, your equipment will remain running cool.  If you need help to determine the correct Cabinet Cooler, inside or out, you can either contact an Application Engineers at 800-903-9247 or fill out our Cabinet Cooler Sizing Guide.

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

 

“The sun” image courtesy of Lima Andruška, https://creativecommons.org/licenses/by-sa/2.0

More Cooling At A Kuwaiti Sewage Station

Overheating electrical enclosure at Kuwaiti sewage station
Overheating control panels for sewage pumps

Last week I wrote a blog about cooling sewage pumps at a facility in Kuwait.  The pumps in question were overheating and needed a way to cool the pump motors down to ambient temperatures.  And, fortunately, our Super Air Amplifiers proved to be a great fit.

On the other side of the same facility, there were control panels for 3.3kV pumps that were also experiencing an overheat condition.  But, the motors were operating properly, it was the electrical panels that were tripping due to excessive heat.

The overheating of the electrical panels would shut down the pump motors, bringing operations to a screeching halt.  What the end user needed was a way to regulate temperature within the electrical panels that was small, effective, and easy to use.

This application, and its requirements, were a perfect fit for our Cabinet Coolers.  Cabinet Coolers are small, effective, easy to install, require no maintenance, and are incredibly easy to use – once installed and setup, they regulate themselves.

By receiving a completed Cabinet Cooler Sizing Guide, EXAIR engineers are able to calculate heat load for an enclosure and recommend a suitable solution.

If you have an overheating cabinet or electrical panel, call an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Video Blog: Cabinet Cooler Systems also Stabilize Relative Humidity

EXAIR Cabinet Cooler Systems are able to cool your electrical panels using only clean, dry compressed air. Other systems such as cooling fans or heat exchangers use ambient air full of dust and humidity. The temperature of ambient air also fluctuates with the seasons and will be very warm in the summer months, which degrades their ability to cool as the temperature rises. One of the myths about compressed air cooling is that humidity from the compressed air source will enter the cabinet. A water/dirt filter separator will prevent condensate from entering the cabinet and since relative humidity is carried away with the hot air exhaust, relative humidity will stabilize to 45%. This video shows how quickly EXAIR’s Cabinet Cooler Systems will have an effect on relative humidity.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

A Few Questions about Powering Cabinet Coolers

Dual CC outside
NEMA 4X Dual Cabinet Cooler

Not too long ago, I was contacted by one of our customers regarding the Cabinet Cooler Systems and the quality of the compressed air used to power them.

The specific questions were:

  1. What happens if the compressed air gets dirty with oil or other particles if sufficient filtration is not available at the facility where Cabinet Cooler is being used?
  2. Where does the oil particle go, into the cabinet or out through the hot exhaust or both?
  3. If it goes into the Cabinet Cooler, should one expect a spray or will it simply form small droplets?
  4. Is there a way to filter the cold air outlet?

Dirty, oil laden air would exhaust throughout the Cabinet cooler (both hot and cold flows) as well as into the inside of the attached cabinet if the air were contaminated and there was not any filter located up-stream of the Cabinet Cooler System. This is precisely why we always recommend the use of filter/separator and oil coalescing filters to clean up the compressed air before it goes into the Cabinet Cooler. In fact, we include a five micron, auto-drain, filter/separator with all our stock systems. If oil is a known contaminant in a customer’s system, we will also recommend use of an oil coalescing type filter which we can provide as well. Without a coalescing filter, you can expect any oil in the compressed air supply to be atomized into a vapor which then has possibility of settling on components inside the cabinet.

Filtering the compressed air while it is still in its compressed state and before it goes into the Cabinet Cooler is the only way to make sure that the air is properly cleaned before processing through the Cabinet Cooler System. Filtering the air after it has gone through the Cabinet Cooler System is not possible. Many filtration systems rely on the high velocity of the compressed air for their filtering capability. If it is no longer in its compressed state (a condition that exists at the cold outlet of the Cabinet Cooler), then the right conditions for proper treatment do not exist. Also, by the time the air exits the Cabinet Cooler, your primary need for it is going to be for cooling anyway. Attempting to add filtration to the cold air output will interfere with the cooling function, which negates the purpose for having the Cabinet Cooler.

As compressed air and the systems that produce it become more widely understood, filtering, drying and removing oil from the compressed air stream are tasks that are done on the production side of things.

The best way to proceed is to have the necessary filtration on the compressed air supply, at the point of use, even if the facility has filtered, clean, dry air. It would still be good to employ it just in case any up-stream equipment that is normally used to clean up the air, went down for some reason. I call it the belt and suspenders method. The redundancy is worth the investment.

Neal Raker, International Sales Manager
nealraker@exair.com

Cabinet Cooler Systems Prevent Heat from Causing Control Panel Problems

No matter the time of year, we routinely help customers solve overheating problems with electrical enclosures.  Sometimes these problems are ongoing and not dependent on the external environment.  Other times, seasonal temperature rises cause enclosure temperatures to creep higher and higher until thermal runaway takes hold and/or components fail.

To prevent an overheating condition, and to keep electronics operational, we help countless customers calculate their heat load and recommend Cabinet Cooler Systems accordingly.

Such was the case for an OEM which contacted me recently with the enclosure below.

Can you cool this 1
An industrial electrical enclosure in need of an EXAIR Cabinet Cooler System
Can you cool this 3
Left half of the enclosure
Can you cool this 2
Right half of the enclosure

Our customer manufactures and installs electrical enclosures for use in industrial environments.  This particular enclosure has been in use for several months, and recently encountered an overheating condition on a hot summer day.  I’ve had the pleasure of working with this particular OEM on multiple occasions, so along with the photos above, they supplied all relevant information from our Cabinet Cooler Sizing Guide, and even the sketch below.

Can you cool this 4
Dimensional sketch

Gathering details like the sketch above allow us to recommend the best possible solution for the problem at hand.  For example, knowing that the cabinet is composed of two sections and completely sealed from each other allowed for installation of (2) separate systems for each side.  This allows for separate temperature controls, tailored to the specific devices inside each side of the cabinet halves.

If you have an application similar to the one above, or need assistance with your application, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Summer Returns & So Does Heat Related Damage to Electrical Cabinets

Summer has not officially arrived in the Northern Hemisphere, according to the calendar, but temperatures have started to push 90 degrees Fahrenheit here in Cincinnati. As the temperatures increase, your electronics may start to feel the heat. High temperatures can cause circuits breakers to trip, controllers to shutdown, and connectors to be very sensitive.  We have seen electronics lose machine control, report bad readings, or if the heat is not managed promptly, damage circuitry. EXAIR Cabinet Coolers Systems are a simple, quickly installed and effective solution to heat related problems. Beside being installed in minutes and shipping from stock, they have additional benefits over fans, air conditioners and heat exchangers.

During the heat of the summer, fans, air conditioners, and heat exchangers may fail when you need them most.  For instance,  a fan and a heat exchanger work because the temperature differential between the ambient temperature and the inside of a cabinet is large. As the temperature rises, the ambient temperature goes up and a fan or heat exchanger lose their ability to remove heat from the cabinet. In a climate controlled environment this works great, in a hot plant floor without air conditioning, it is a recipe for failure.

So if fans aren’t a good solution you may turn to air conditioners in the summer because they can still produce very cold air at much higher ambient temperatures. You will need hours to install them, cross your fingers that they arrive undamaged, hope the condenser and other moving parts don’t fail and provide a drain for the condensate. If you are in a dusty environment, the filters will clog more often in the summer and require more maintenance. As the temperature rises the air conditioning systems run more often which means they pull in more air and particulate that will clog the filters and lead to reliability problems in the compressor. This compressor is subjected to more of a work load in the summer and more airflow restriction, if the filters are not changed often. This may lead to more air condition filters during the summer months.

EXAIR compressed air operated Cabinet Coolers System are a great solution for cooling enclosures. They operated via vortex cooling which requires no moving parts or filters from the outside air.  They drop your compressed air temperature 50 degrees Fahrenheit.  Mounting requires a compressed air supply, a standard electrical knockout, and the locknut that comes with the Cabinet Cooler System. The cooling is produced immediately with no lag time. A Electronic temperature controller is a available to maintain a temperature of your choosing.

ETC Dual CC Systems
Cabinet Cooler with ETC

Cabinet Cooler Systems are maintenance free with a clean dry supply of compressed air. Recently, we tested a cabinet cooler that was over twenty years old that still tested to our production standard.  The customer was delighted to hear that is was working so well they wanted it returned.  Cabinet Cooler Systems are available for NEMA 12, NEMA 4 and NEMA 4X enclosures. Kits include compressed air filtration to keep water, dirt and oil out of your enclosure. If you see an open panel door this summer, look into a Cabinet Cooler Systems. We can help you beat the heat.

fan enclosure
Cabinet Coolers will help you avoid this situation.

EXAIR’s Cabinet Coolers are in stock and ready to ship to you same day if ordered by 3:00 pm EDT. You can have it tomorrow if you like.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

 

Like a Donkey Between Two Haystacks

90Day_Temp

Having been born and raised in the northern climates, for me 80 degrees is hot. So when temperatures soar into the 90’s I really struggle to cope. Bad news is that according to NOAA, we are in store for above average temperatures for the remainder of the summer!

High temperatures are not only uncomfortable for we humanoids, electronics suffer as well. The demand for panel cooling is extensive and my company, EXAIR, produces Cabinet Cooler systems. There in lies my dilemma. I would like to wish for the heat to go away but then that would be wishing ill for my company. I’m like a donkey trying to decide between two hay stacks.

So, I will stay in my air conditioned cubical and calculate cooling requirements for customers. I would welcome the opportunity to assist you with your panel cooling requirements. Give me a call at 1-800-903-9247

Joe Panfalone
Application Engineer
Phone (513) 671-3322
Fax (513) 671-3363
Web: http://www.exair.com
Twitter: http://www.twitter.com/exair_jp
Facebook: http://www.facebook.com/exair