Humidity

Computers in College Computer LabI talked with my children the other day about how quickly the world of information access is changing. They were fascinated to learn about how I went to college in the 1990s (in my head at least, it wasn’t that long ago!), and I had to (gasp!) walk all the way to the computer lab on campus to type my papers, as hardly anyone had a computer of their own. Getting that critical paper completed on time meant pre-planning to make sure it wasn’t too cold or rainy to walk to the lab and that you wouldn’t get to the lab at the same time as the rest of your colleagues. I can distinctly remember forcing myself to learn the new Mac OS because the Computer Science majors occupied all the Windows PCs!

Telecom Network Reliability

Now here we are today, and we don’t usually have to worry about pre-planning to avoid weather or computer lab availability…but watch out if our YouTube cat video doesn’t download and play immediately.

The expectation in today’s world is instant gratification, with no downtime or download delays.

The traditional standard for telecom network reliability, measured at the service level, is six-nines or 99.9999%, which translates to an average of 32 seconds of downtime per year per service.

Electric Vehicle (EV) Charging Network Reliability

It is also interesting to watch the burgeoning EV market. New buyers are entering the marketplace, and some of these consumers have ‘range anxiety’ – the fear of not having enough charge to reach their desired destination. EV Charging companies are mitigating this with more extended range battery packs and a growing number of well-placed EV charging stations.

The expectation of EV Charging uptime is not yet to the “six 9’s” of telecom, but they are not far behind. The CEO of EV Go touts 98% uptime on their fast-charging network. OEM’s in this space are discovering they can tout reliability (uptime) as a market share growth strategy.

Uptime Risks

Because Telecom and EV Charging cabinets both involve outdoor exposure, precautions must be taken to ensure hardened designs. One failure mode that isn’t as well documented is induced condensation.

Electronics enclosure designers must minimize the chance for induced condensation, as this could lead to electronics failure. The formation of condensation is one of the biggest dangers for electrical enclosures. Condensation is caused by hot, humid air coming in contact with a surface colder than the ambient air dew point. When the humidity is high, it does not take a significant temperature change to cause condensation to form inside the cabinet.

If condensation occurs, potential failure modes include:

  • Short circuits
  • Corrosion
  • Premature breakdown
  • Contamination by mold and other organisms
  • Water drainage from enclosures
  • Risk of electrical shock to employees

 Uptime Risk Mitigation

There are different tools to minimize condensation inside electronics enclosures. The most effective tool is a comprehensive design that considers both temperature and condensation. DC Heaters like those offered by STEGO are an excellent fit to minimize condensation buildup. STEGO products include PTC, touch-safe PTC, and flat heaters, as well as an explosion-proof option.

By thinking ahead and planning for condensation, designers can maximize uptime for their clients, leading to enhanced market share and customer satisfaction. You’ll be able to use your mobile phone to see more cat videos and get fewer panicked calls to diagnose what went wrong in the field!

Designing complex electronics that perform perfectly outdoors is, well, complex. At STEGO, we believe that protecting those complex projects from extreme climates should be the simplest part of your design. That’s why we use German engineering to create the highest quality thermal management components to protect your designs from anything Mother Nature throws at it. We’ve been pioneering Thermal Management for over 40 years now. With STEGO parts installed, you can rest easy that your complex design is reliably protected for the long haul.

 

When it comes to designing enclosures that contain electronics for maximum longevity, many factors must be considered, including geographic location, temperature, moisture exposure, and the risk of induced condensation. Some designers assume that their NEMA enclosure is waterproof, and so…why worry about all that?

In a recent Stack Exchange web post (https://tinyurl.com/4cmzph46), the author asked for help regarding a sealed electronics enclosure that “had the top cover … screwed on properly, and there was no way water (could) get in.” However, there was clear evidence of condensation after investigation of an intermittent functional failure. 

How did this happen?

There is a misconception that NEMA 4 enclosures provide all the protection needed to prevent moisture-related failures. Even though NEMA 4 is recognized as the standard for keeping moisture from entering an enclosure – it does NOT prevent condensation-induced risks. 

Condensation is caused by warm moist air coming into contact with a surface that is colder than the air’s dew point. Most designers know to account for extreme temperature swings and relative humidity; great designs also account for the condensation-induced use case. 

Induced condensation can stem from two scenarios:

  1. high humidity in combination with day-to-night temperature swings (in some parts of the world, temperatures exceed +50°C. In others, they fall to –40°C), or
  2. heat generated from running electronics in combination with ambient cold temperature (less widely known).

Either scenario above could result in undesired condensation. Over time, the electronics exposed to this scenario could lead to potential device failure, manifested as a short circuit, corrosion, or contamination by mold and other organisms. These could also lead to unexpected water drainage from enclosures and the potential risk of shock to employees.

Beyond the physical issues created, consider the time and resources spent finding a malfunctioning terminal or other electrical components that have been affected by moisture is somewhat difficult as any related problems are not always critical in the first place. As the malfunction triggers inconsistent product performance, the maintenance team must manually check all the electrical components. If there are a hundred electrical boxes to check, the time required to go through all of these can be extensive and result in increased operational costs.

There are different tools to minimize condensation inside enclosures. The most effective tool is a comprehensive design, taking into consideration temperature and condensation. To protect the user and technician, enclosure designs must include devices to compensate for temperature (i.e., thermostat) and condensation (Hygrostat).

Don’t assume that NEMA fixes all that ails you. If you aren’t sure about your design and withstanding pesky condensation, reach out to one of our experts.

Designing complex electronics that perform perfectly outdoors is, well, complex. At STEGO, we believe that protecting those complex projects from extreme climates should be the simplest part of your design. That’s why we use German engineering to create the highest quality thermal management components to protect your designs from anything Mother Nature throws at it. We’ve been pioneering Thermal Management for over 40 years now. With STEGO parts installed, you can rest easy that your complex design is reliably protected for the long haul.