3 Enclosure Design Mistakes That Hurt Reliability

An electrical enclosure that passed commissioning without issues can still become a weak point of the system months or even years later. The usual reason is not a defect but a change: higher loads, more intensive production, newly added equipment, or different ambient conditions. Fandis highlights three design mistakes that most often lead to this situation.

1. Sizing the load without considering the real application

A machine-mounted enclosure with drives, PLCs, and power supplies has a very different thermal loss profile than a power distribution enclosure. Rated current alone is not enough: the designer should also evaluate how the components behave over the actual operating cycle.

2. Laying out the interior without a thermal strategy

The position of each component affects airflow and heat dissipation. High-loss parts such as inverters, power supplies, and electronics can create hot spots if the layout is not assessed. Traditional ventilation may not be sufficient; intelligent, dynamic ventilation that runs only when needed helps keep internal temperatures stable. 3D CAD environments can also support thermal design, with accuracy depending on the type of simulation and the data available.

3. Ignoring how the system will evolve

Enclosures rarely stay unchanged. New devices, modified production processes, or different environmental conditions all shift the original thermal balance. A reliability-oriented design plans for monitoring and managing new operating conditions throughout the life of the enclosure.

Design checklist

• Have the thermal losses of the main components been assessed?
• Is the thermal management system suitable for the application?
• Does the internal layout support heat dissipation and maintenance?
• Does the ventilation adapt to actual operating conditions?
• Were the requirements of EN 61439 and, where applicable, UL 508A considered in the final configuration?

Fandis ventilation at Unisun

Unisun is an authorized Fandis reseller. Browse the Fandis collection, including filter fans and filters for enclosure ventilation.

Contact us

Tell us about your enclosure and heat load, and we will help you find the ventilation solution best suited to your application. Write to info@unisun.si, call +386 1 777 86 46 or use the contact form. We typically respond within one business day.

Source: Fandis S.p.A., blog.fandis.com.