Electronic Enclosures

About Electronic Enclosures and Electronic Enclosure Manufacturers Including: Computer Enclosures, Metal Box, Metal Enclosures, NEMA Enclosures & Plastic Enclosures.

Electronic enclosures house a wide range of electronic equipment. They are a standard component in most industrial settings. These enclosures protect electrical and electronic components from moisture, chemicals and dust, which can damage the equipment permanently. Electronic enclosures are typically box-shaped and often have removable panels or doors to provide the easy access needed for maintenance and equipment modifications. The temperature and humidity within an electronic enclosure may also be controlled. Electronic enclosure manufacturers can produce electric enclosures as small as a pushbutton enclosure, which simply protects the surrounding area and wiring of a electrical push button, or as large as a room in which is housed large, sensitive computer networks and wiring. Wiring itself often needs to be enclosed in a protective enclosure, especially at the connection points of two or more types of wire or from the wire to the main equipment. These types of enclosures are called junction or terminal boxes.

The housing material used by electronic enclosure manufacturers is generally made from sheet metal, such as stainless steel or aluminum. However, other materials, such as fiberglass, high strength polymer plastics and other composites are also used, especially for portable devices. These materials are lighter weight and more durable than steel. Materials should be chosen for the desired properties of electrical, thermal and fire resistance and strength. Electronic enclosures can be coated with a substance that protects the internal equipment from EMI, which stands for “electromagnetic interference." This type of extra protection is necessary for sensitive electronic equipment in which EMI would disrupt efficient performance of the circuitry inside the equipment.

Electronic enclosures are made available by electronic enclosure manufacturers for portable devices, as well. There are two basic sizes of portable devices: pocket and handheld. Pocket boxes measure no more than two or three inches and typically house a single board and components. Pocket enclosures offer several different types of accessories, including body clips, keypads, key rings and buttons. Handheld enclosures measure between six and 11 inches and house larger components than pocket enclosures and multiple boards. Handheld boxes offer a wide variety of accessories and can easily accommodate cable glands, display areas, separate battery compartments and recesses for membrane keypads or product labels. Both handheld and pocket enclosures are usually made of ABS (acrylonitrile-butadiene-styrene) plastic.

Customized enclosures are commonplace in many industries, such as the medical, automotive and agricultural industries. Electronic enclosures should be an integral part of the design and should be considered early in the process, rather than near the end, to prevent problems or critical failures. Factors to consider when selecting an appropriate enclosure include size, NEMA type, materials of construction, mounting and security. The enclosure size is determined by the dimensions of the equipment that the electronic enclosure will house, as well as other factors, such as service connections, equipment mounting, internal and external access, thermal limitations, maintenance, economics and future expansion. The NEMA type selected depends on the environment of the application. Materials for enclosures should meet corrosion and strength requirements. Mounting methods for electronic enclosures include floor standing and pole-, wall- and pedestal-mounting. Padlock hasps, locking latches, key locks, fiberglass latches, wing-knobs and screw covers provide security for the enclosure.

Electronic Enclosures and Electronic Enclosure Manufacturers Images Provided by Compac Development Company

Electronic Enclosures and Electronic Enclosure Manufacturers Image Provided by Equipto Electronics Corporation

Types of Electronic Enclosures

• Computer enclosures are housings made specifically for computers. Computer enclosures are usually made of metal and are used to protect the inner electronics from dust and moisture damage.
  
• Custom enclosures are made to the detailed specifications of the customer. The sizes can vary to enclose a range of equipment, from a fuse box to a number of electronic devices and cables housed in a separate room, referred to as network racks.
  
• Double-shielded enclosures have an inner wall that is isolated from the outer wall with the exception of the region where the power-line filters and coaxial connectors penetrate. Double shielded enclosures can also be rooms.
  
• Electronic cabinets are filters designed to protect electronic parts from damage caused by dirt, oil, dust and moisture. Electronic cabinets, used in virtually every industry, give electronic components a plane of operation that improves their efficiency.
  
• EMI shielding (http://www.emi-shielding.net) involves using materials, such as filters, gaskets and coatings to block, absorb or redirect electromagnetic waves, in order to prevent electromagnetic interference (EMI) from harming sensitive equipment. These materials are attached to the metal surface of such enclosures.
  
• Junction boxes are a type of enclosure used specifically for wiring and the connecting of wiring to a larger unit and are often constructed with metal material. Junction boxes must have a cover plate and should be easily accessible.
  
• Metal boxes are metal enclosures that protect electronics.
  
• Metal enclosures are typically made of either aluminum or sheet metal. Metal enclosures are being replaced by enclosures made of lighter, more durable composites.
  
• NEMA enclosures are a specific type of electronic enclosure that is certified by the National Electronic Manufacturers Association (NEMA), which rates the enclosures bases on the type of application for which they are used. NEMA enclosures are typically made from carbon or stainless steel and can range in size from a pushbutton panel to a room-sized panel.
  
• Plastic enclosures are plastic housings that protect electronics.
  
• Pushbutton enclosures are either rectangular or wedge-shaped. Pushbutton enclosures have cutouts for surrounding and securing pushbuttons and can be mounted to a wall, pedestal or suspension system.
  
• Terminal boxes are similar to junction boxes and are used for the housing and protection of a connection point between two different types of wire.

Electronic Enclosures Terms

Attenuation – A reduction in signal strength. Attenuation can occur naturally during normal signal transmission, or it may be produced intentionally by inserting a device in the path of the signal to reduce signal strength.

Bounding Surface – The outer surface of the electrical enclosure.

Cabinet – Often used interchangeably with either enclosure or rack. It is a piece of equipment designed to house or enclose something, such as electrical or process equipment.

Cable Glands – Seals that prevent water, dust, etc. from entering the enclosure at the point at which the cable is brought through the enclosure wall. Often, cable glands are installed via a gland plate.

EMI (Electromagnet Interference) Emission – The unintentional or undesired exiting of potentially interfering electromagnetic energy from electrical/electronic sources.

Flame Retardancy – The ability of a material to resist burning, sparking, sputtering or dripping when brought into contact with a naked flame. Not all enclosures are flame retardant.

Gear Tray – Also called a “mounting plate” or “mounting pan,” it is a shelf that allows the mounting of equipment inside the enclosure. Gear trays are typically located at the rear of the enclosure, though some may be movable.

Gland Plate – Removable section of the enclosure, usually located on the bottom. The gland plate can be removed to allow the easy fitting of cable glands.

Permeability – The extent to which a material can be magnetized.

Plinth – Term used to describe various styles of mounting bases for floor-mounted enclosures.

Shielded Cables – Cables that have shields, such as braids or foils, to prevent EMI from entering or exiting the cable.

Rated Current – The input current of the equipment as declared by the manufacturer.

Shielding Vents – Vents that are used for HVAC or simple ventilation of shielded products, such as cabinets, rooms or enclosures. Some shielding vents also provide high shielding or air filtering.

Shielded Windows – Shielding consisting of a thin conductive film on the glass or a fine-wire mesh or metalized open-mesh textile.

Shielding Gasket – A material that maintains shielding effectiveness across a seam or gap in an electronic enclosure.

Type 1 – A NEMA rating indicating that the enclosures are intended for indoor, non-hazardous locations. Type 1 enclosures are mainly used to provide protection against limited amounts of falling dirt.

Type 3R – A NEMA rating indicating that the enclosures are intended for use in outdoor, non-hazardous locations. Type 3R enclosures are mainly used to provide protection against falling rain and external ice formation.

Type 4 – A NEMA rating indicating that the enclosures are intended for indoor or outdoor use in non-hazardous locations. Type 4 enclosures are mainly used to provide protection against splashing or hose-directed water, damage from external ice formation and windblown dust or rain.

Type 12 – A NEMA rating indicating that the enclosures are intended for indoor use in non-hazardous locations. Type 12 enclosures are mainly used to provide protection against dripping, non-corrosive liquids, circulating dust and falling dirt.