Electrical Enclosures

Enclosure Design for Environmental Controls

Electrical controls and power enclosures cover a wide range of types, mounting, and applications. An enclosure may be indoor or outdoor, and floor mounted, pole-mounted, or pedestal.

An equal number of sizes and levels of protection from the elements and for safety are available. These variables have some influence on the interior design of the electronic equipment and switchgear within the enclosure.

Numerous electrical standard agencies dictate best practices for safety and local codes for building and wiring. All of the standards are readily available now by the internet and your company probably already follows best practices for adhering to the regulations and safety.

This article primarily deals with industrial type enclosures found in manufacturing facilities around the world. The type enclosure and electronics that control production lines and factory equipment. Designers can apply the logic introduced to other control enclosures like security and safety systems, remote gas & oil pipeline control systems, and even windmills.

The basic layout of power and electronics in industrial enclosures

Outside the codes and regulations is a design that facilitates equipment maintenance while adhering to the safety standards. You might have noticed stickers on panels or electrical enclosures that specified that only qualified individuals should open the panel or work on the equipment housed inside.

Unfortunately, several things can happen when an unauthorized or trained person gains access to the components inside the panels.  

Safety is the primary concern. The switchgear, electrical connections, and devices are exposed to contact. That contact can result in burns, electrocution, and death. Even an experienced electrician or electrical engineer can contact live circuits, resulting in painful results. An inexperienced individual coming in contact with a power circuit can be deadly.

It is advisable to always turn off the power before opening a control panel. There are occasions where service and maintenance need doing without shutting down. Organized wiring and spacing are even more critical when working on these types of systems.

When the manufacturer and designer take the time to organize the internal circuits and controls logically, they will be safer and easier to maintain.  

Best practices and logical arrangements

When possible, it is important to orientate the switchgear that controls the incoming power so that it can be shut off before opening the cabinet. Panels exposed to the public like traffic and safety panels don’t have access to switchgear externally since they don’t want someone to shut off the power supply. These types of cabinets have locked entry with the switchgear controls internally mounted.

Industrial control panels have switchgear with levers protruding from the panel to be turned off or on before opening or closing the panel doors. Of caution, even these panels will have hot terminals on the input side of the circuit breaker. A practical mounting for this type of switch is near the top right corner of the panel. This positioning keeps the input terminals out of reach for most repairs or maintenance.

A wrench or breaker bar coming into contact with 3 phase 240-480 Volt line power can become a disaster.

Windmills are one of the many applications suitable for the simplicity of the design and effectiveness of PTC elements to control heating.  Adverse environmental conditions requiring reliable temperature control require quality manufactured components to ensure operation.  See what components might help you solve your next industrial temperature design issue.