Keeping electrical equipment running during the winter weather

Depending on where your equipment is placed, detailed consideration into electrical enclosure material, design, thermal management and durability are crucial to keep the equipment inside running smoothly.

The critical role of enclosures

Sophisticated and sensitive technology must be protected by closely controlled housings or enclosures, which can safeguard delicate electrical components and ensure that they work reliably and cost-effectively over their lifetime.

Enclosure housings must ensure that the equipment is shielded from the extremes of being sited in outdoor environments, including seasonal temperature variations, trackside vibration, and potential acts of vandalism.

A damaged or otherwise compromised enclosure can lead to IT failures, system downtime, and, in critical applications such as for signalling equipment, safety hazards. To mitigate these risks, enclosures must be designed and built to withstand environmental stresses, provide adequate thermal management, and have robust security features.

Rittal, a leading provider of enclosures and enclosure cooling products for IT and electrical equipment, provides superior protection for electrical equipment housed outdoors and in harsh environments.

Superior protection from the elements

Water can, of course, have a detrimental corrosive effect on outdoor enclosures, if the incorrect enclosure is used. That's why it's important to choose the right enclosure for the job. Rittal's enclosures are designed with multiple protective features to safeguard against rainwater and moisture, helping equipment to survive those tough winter months. All Rittal's enclosures achieve an IP rating 55 which protects against wind, rain, and dust.

Most notably, all Rittal's outdoor enclosures incorporate an overhanging double-skinned roof design. This creates a horizontal seal at the top that guarantees better protection than the standard vertical door seals. Rainwater can run off the roof edge without collecting around the seams, avoiding issues such as rust and corrosion.

The double wall enclosure construction creates an additional layer of protection where condensation can form without damaging the inner layer with the control panel. This small air pocket also provides an effective thermal barrier against heat transfer.

Tampering security measures

Inclement weather may not be the only threat posed to equipment housed outdoors. Restricting unauthorised access to outdoor equipment is an important consideration to avoid damage or safety hazards. Outdoor enclosures often house vital equipment, such as railway signalling control panels for example, which if tampered with would be detrimental to the running of trains. It's important, then, to place equipment inside enclosures that are designed to deter unauthorised access, for example, with robust locking mechanisms, impact-resistant materials, and surveillance equipment.

Rittal enclosures undergo rigorous testing and simulations, such as attempted access using common hand tools over an extended period. Rittal's resistance class rating 2 illustrates that its enclosures can withstand a sustained period of attempted vandalism with screwdrivers and hammers; the goal to allow enough resistance time for the vandal to be deterred.

Rittal enclosures also feature a labyrinth effect design, so the panels must be dismantled in a particular order to access the inside to deter unauthorised intruders.

Although you can still use traditional keys with Rittal enclosures, they also support contactless NFC access to allow technicians to access the enclosure quickly and efficiently while ensuring authentication. Customers can feel confident that their assets are well-shielded from tampering risks no matter the location.

Understanding enclosure materials

When choosing materials that will face all kinds of outdoor weather conditions, it is important to weigh up the pros and cons of each option. It's very common to favour stainless steel enclosures over aluminium, or plastic GRP, for outdoor applications.

But once again, the enclosure should reflect the application.

Stainless steel provides initial corrosion protection with an extra layer of powder coating paint. However, this can become vulnerable in the long-term. Stainless steel can rust and disintegrate with exposure to salt particles and water.

When aluminium encounters salt and moisture, it oxidises and creates its own protective barrier on the metal that can self-regenerate, and therefore boasts better longevity.

The strength-weight ratio of aluminium allows for thinner yet robust sheets which lowers material costs and provides more space inside for cabling. The lighter weight also saves resources on handling and transportation.

Aluminium has a higher IK rating than stainless steel and can better withstand impact. Stainless steel tends to crack whereas aluminium will bend.

However, in a coastal environment, 316L Marine grade stainless steel would be more suitable than aluminium. The higher molybdenum percentage in the composition prevents salt water from corroding the metal.

Enclosure features

An IP66 rated enclosure is not usually designed to deal with the consequences of prolonged or heavy rainfall, whereby rainwater falling on the enclosure collects next to the door seal. Not only is rainwater slightly acidic (because of the CO2 within the atmosphere), but it also contains other contaminants that, collectively, will degrade the seal over time. Plus, when rainwater freezes, it expands, pushing the door away from the enclosure body, leading to internal leaks.

By contrast, a specially designed outdoor enclosure has either a roof canopy or rainwater strip that stops the water from being trapped between the door and the body wall, thereby protecting the seal. This means the enclosure lasts longer and will provide better protection.

In summary, the type of enclosure you need will vary by application, industry, and location. If you are specifying for outdoor use, make sure that the protection it offers is robust and appropriate, such that it will be able to withstand the unique demands that are placed upon it into the future. It is, after all, protecting equipment that could cost tens of thousands of pounds to replace, not to mention the additional cost of any problems this may create for the infrastructure, which the equipment is designed to control.