How Can I Stay Calm When My Control Panel’s Overheating?

Published on by Russ Bowman

We’re in the dog days of summer (in the Northern Hemisphere) for sure…or, as we call it, “Cabinet Cooler Season.” If you’re having heat-related problems with a control panel, there are plenty of cooling options out there, but you’ll be hard-pressed to find one that’s as durable, reliable, available, and easy to install as an EXAIR Cabinet Cooler System. All we have to do is find the right one for your enclosure, and we have a couple of different ways to do that:

Cabinet Cooler Systems Sizing Guide: We’ve had this on our website, and in our catalog, for years now. We can also email you one, if you want to print it out & fill in the blanks. Then, you can either email it back, or you can call us with the data. It only takes a minute to do the calculations, and we do it over the phone all the time.

Cabinet Cooler System Calculator: This one’s for the do-it-yourself-ers, and it uses the exact same formulas that an Application Engineer will use if you submit a Sizing Guide. There are still some situations where you might need to contact us — if your enclosure is in an explosive environment, an area with a hazardous classification, or if the heat load is outside the parameters of our stock Cabinet Cooler Systems, the Calculator is going to politely decline to make a selection and refer you to an Application Engineer. Of course, if you have ANY questions about the application or the Cabinet Cooler products, don’t hesitate to call, even if the Calculator doesn’t make you.

Here’s what we’re going to ask for, and why:

  • Enclosure dimensions. To calculate the heat transfer surface area
  • Current Internal Air Temperature. This is the starting point for figuring out the internal heat load…how much heat the components inside the box is generating. This needs to be the air temperature – don’t use a heat gun, or you’re going to give me the surface temperature of something that may or may not be close to what I need. Just put a thermometer in there for a few minutes.
  • Current External Air Temperature. We’re going to compare this to the internal air temperature…the difference between the two is proportional to the heat load. Also, if there’s anything cooling the enclosure right now (like circulating fans; more on those in a minute), this reading is key to figuring out how much heat they’re removing.
  • Maximum External Air Temperature. How hot does it get in the area on, say, the hottest day of summer? We’ll need this to calculate the external heat load…how much heat the enclosure picks up from its surroundings.
  • Maximum Internal Temperature Desired. Most electrical and electronic component manufacturers publish a maximum operating temperature of 104F (40C) – it’s kind of an “industry standard.” Based on this, a lot of us in the enclosure cooling business set our products’ thermostats to 95F (35C) – if we’re maintaining the air temperature a decent amount cooler than the components are allowed to get, history and practice has shown that we’re going to provide more than adequate protection. If your enclosure houses something with more sensitive temperature limitations, though, we can work with that too…that’s the only time you’re going to want to put something other than 95F (35C) in this field.
  • Cabinet Rating. This is all about the environment…we offer three levels of protection, per NEMA standards:
  • Other: If the enclosure is mounted to the side of a machine, or a wall in the plant, you really don’t need to put anything there. If it’s outside and exposed to direct sunlight, tell us what the surface finish (i.e., polished metal, painted grey, etc.) is so that we can account for solar loading too. If anything else is unusual or peculiar about the application, let us know that too.
  • My Cabinet Is… Not Vented, Vented, Wall Mounted, Free Standing, Fan(s). We’ll use what you tell us here to verify the heat transfer surface (a wall-mounted cabinet’s back surface isn’t a radiative surface, for example.) Also, I mentioned fan cooling before, so without further ado…
  • Fan diameter or SCFM. If there are fans circulating air into (and/or out of) the enclosure, they’re providing a finite amount of cooling right now. Proper installation of a Cabinet Cooler System is going to require their removal. Running a Cabinet Cooler System on a vented enclosure is just like running your air conditioner with the windows open. So, if we know the size (or the SCFM…sometimes there’s a label on those fans, and we LOVE those folks who do that) then we can use that, and the temperatures you gave us above, to take the fan cooling into account.

Once we (or the Calculator) have that data, we’ll calculate the heat load & specify the right system. Easy as that.

Before I go…here’s a nice little video, walking you through the Cabinet Cooler Sizing Guide. Yes, I just made you read the book before watching the movie…feel free to tell me which one you liked better.

Cabinet Cooler Systems are in stock and available for same day shipment with an order received by 2pm EDT. If you have a panel that needs cooling, we can fix that right now…give me a call.

Russ Bowman, CCASS

Application Engineer
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