
Steel Enclosures & Junction Boxes

Electrical enclosures are designed to house industrial components and to protect them from the surrounding environment. They are also designed to protect operators from electric shock. They come in many different shapes, sizes and materials. Some things to consider when selecting the proper enclosure would be the number of components housed inside and what material and rating will provide the appropriate protection.
The National Electrical Manufacturers Association (NEMA) has devised a rating system to set performance standards for electrical enclosures. Manufactures follow these universal standards when making their electrical enclosures and label them accordingly. The most popular NEMA ratings are listed below.
NEMA 1 provides the least amount of protection and is for indoor commercial applications.
NEMA 3R provides protection against snow, rain and windblown particles. These enclosures can be indoor or outdoor and are commonly used for utility boxes and meter cabinets.
NEMA 4 provides protection against all weather conditions as well as being watertight. These enclosures are commonly used to house hydraulic controls, wiring and operator consoles.
NEMA 4X provides the same protections as NEMA 4 with additional corrosion protection. These enclosures are commonly found in water treatment facilities, marine environments, oil and gas industries and industrial food processing.
NEMA 12 provides a dust-tight enclosure, but are not watertight and should not be used in wash down environments.
Steel enclosures are made with carbon or mild steel for indoor and outdoor enclosures. Carbon steel is a strong and cost-effective material however, it is susceptible to corrosion from exposure to moisture and oxygen. Carbon steel enclosures require a powder coating or paint to provide protection from the elements.
Junction boxes are enclosures that house wire connectors or terminal blocks and are designed to protect the devices from harsh environmental conditions as well as operators from electric shock. They can distribute power from one location to many other locations or they can collect control signals from I/O devices and bring them back to a central control panel or cabinet.
Before mounting to any surface, it is important to understand how the hardware will interface with the enclosure. In many cases, the enclosures will have holes at the corners that can be used to attach any mounting hardware. It is common to see a mounting strut, commonly referring to as a Unistrut, being used with these electrical enclosures. The Unistrut can attach to the enclosure and provide a very strong connection point to either a wall, concrete or pole mount.
When mounting to a concrete wall, there are several things that should be considered to ensure it is done correctly. Industrial concrete anchors provide a very strong and reliable connection that can last a very long time. Make sure that the concrete is thick and strong enough for these types of anchors. Once the anchors have been installed, attach them to the mounting strut that is attached to the enclosure using hardware that is designed for that particular type of mounting strut.
When installing an electrical enclosure on a pole or mass, it is important to make sure that the pole can handle the weight of the enclosure. It is recommended that the pole is made of a very strong rigid material. At least two inch rigid galvanized conduit is recommended. Once the pole has been secured into the ground, strut clamps designed for the size of conduit will attach the enclosure.