Electrical enclosures perform a variety of functions, from housing electrical switchgear, pneumatic pilot devices and low and high voltage instrumentation. Enclosures are available off the shelf in a variety of standard sizes and specifications. They can also be custom made to required specifications, including size, construction material, color and finish as well as type. The NEMA Type 4 enclosure standard covers indoor and outdoor use and offers protection against:
- Corrosion, windblown dust and rain.
- Splashing water.
- Hose directed water.
- Should withstand the weight of standing ice.
Read the rest of the article to find out more about NEMA Type 4x boxes, construction & fabrication materials.
Types of NEMA Type 4x boxes
Specifying the correct type of enclosure is paramount when designing an electrical distribution system. Ensuring that it meets the environmental and safety requirements is also a key considerations. The different types of nema4x junction boxes and enclosures include the following:
- Junction box with hinged cover and clamps.
- Box with clamp cover.
- Wall mount enclosures.
- Pedestal mounted enclosures.
Different custom metal fabrication techniques are used to create the wide range of NEMA Type 4x enclosures listed above.
Enclosure specification
The four most commonly used materials to construct and fabricate NEMA Type 4x enclosures and boxes are as follows:
- 304 Stainless steel
- 316 Stainless steel
- 5052 aluminium
- Powder coated carbon steel.
The choice of material selected for the fabrication of your custom box will depend on several factors which may include project budget, environment for use of enclosure, type of enclosure and dimensions. There is often a requirement for wall mounted boxes to be light in weight and so aluminium may be chosen ois such cases. For rugged environments where there is a risk of physical or mechanical damage then powder coated carbon steel may be a better option.
Construction and fabrication
Apart from withstanding the environmental conditions, enclosures should also offer safety. For this reason, most are fitted with a continuous hinge. Sheets of metal 12, 14 or 16 gauge thick are precisely cut and then folded and welded into the desired shape for the enclosure.
Laser cutting machines are used to cut the panels to size and laser cut entries and cut-outs also feature on most electrical boxes. Grounding facilities including studs are also commonly provided in the base or at the top of enclosures. Rubber gaskets also surround the enclosure doors to help them meet NEMA Type 4x standard specification.