Allied Moulded Electrical Enclosures

Enclosure Selection Basics

Electrical enclosures are cabinets that are designed to house electrical components. Their main function is to protect the components, as well as to protect the operators from electrical hazards. Enclosures are typically made of solid plastics, fiberglass and metal materials, such as carbon steel, stainless steel and aluminum.

One of the most important things to consider when selecting an electrical enclosure is the NEMA rating. NEMA stands for National Electrical Manufacturer Association. They have developed a rating system which determines the types of environments an electrical enclosure can be used in. 

NEMA 1 and a NEMA 12 enclosures

Both of these enclosures are intended for indoor use only. They are both dust resistant. The NEMA 12 enclosure is rated for damp environments. The NEMA 1 is rated only for dry environments.  

NEMA 4 and NEMA 4X enclosures

Both of these enclosures can be used indoors as well as outdoors. They are both dust resistant. They are also water resistant and corrosion resistant. NEMA 4X has an extra layer of corrosion resistance.

NEMA 7 enclosures

This is a more specific type of enclosure that is rated for use in hazardous environments. It is rated to contain an explosion within the enclosure and not cause any sort of external hazard. 

Size

When selecting the size of an enclosure, it is important to consider the following: how much space will the electrical components occupy, how much space is needed around each component, is there enough room to run all of the wires and how much space is needed outside of the enclosure?

Temperature

When selecting an enclosure, it is important to consider both the ambient temperature and the temperature that is generated inside of the enclosure. When an enclosure is located outside in direct sunlight, that heat can be transferred inside the enclosure. Also, each component inside of the enclosure generates a certain amount of heat.