Enclosure (electrical)
Encyclopedia
Cabinet (furniture)
A cabinet is usually a box-shaped piece of furniture with doors or drawers for storing miscellaneous items. Some cabinets stand alone while others are built into a wall or are attached to it like a medicine cabinet. Cabinets are typically made of wood or, now increasingly, of synthetic...
for electrical
Electrical equipment
Electrical equipment includes any machine powered by electricity. They usually consists of an enclosure, a variety of electrical components, and often a power switch...
or electronic equipment to mount switch
Switch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
es, knobs and display
Display device
A display device is an output device for presentation of information in visual or tactile form...
s and to prevent electrical shock to equipment users and protect the contents from the environment. The enclosure is the only part of the equipment which is seen by users; in many cases it is designed not only for its utilitarian requirements, but also to be pleasing to the eye.
United States
In the United States, the National Electrical Manufacturers AssociationNational Electrical Manufacturers Association
is the association of electrical and medical imaging equipment manufacturers. Founded in 1926 and headquartered near Washington, D.C., its approximately manufacture products used in the generation, transmission, distribution, control, and end use of electricity. These products are used in utility,...
(NEMA) publishes standards for the performance of various classes of electrical enclosures. The NEMA standards cover corrosion resistance, ability to protect from rain and submersion, etc.
International
For IECInternational Electrotechnical Commission
The International Electrotechnical Commission is a non-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology"...
member countries, standard IEC 60529 is classifying the ingress protection rating (IP Codes) of enclosures.
Proposed generic requirements
Telcordia TechnologiesTelcordia Technologies
Telcordia Technologies, formerly Bell Communications Research, Inc. or Bellcore, is a telecommunications research and development company based in the United States created as part of the 1982 Modification of Final Judgment that broke up American Telephone & Telegraph...
has proposed generic requirements for electronic equipment cabinets. These requirements were developed with the input of United States North American service providers. GR-487, Issue 3, Generic Requirements for Electronic Equipment, provides criteria for analyzing electronic equipment cabinets used in a variety of outside plant environments and applications, including wireless. It includes proposed functional design criteria, generic mechanical and environmental requirements, desired features, and performance tests.
Materials
Electrical enclosures are usually made from rigid plasticPlastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
s, metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
s, particularly steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
and aluminum, and natural or processed wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
. They may be made for a specific purpose (e.g., the metal, plastic, or wooden box of a particular radio receiver) or to accommodate any equipment to which they are suited.
Terminology
Enclosures for some purposes have partially punched openings (knockouts) which can be removed to accommodate cableCable
A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
s, connector
Electrical connector
An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly. The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or...
s, or conduit
Electrical conduit
An electrical conduit is an electrical piping system used for protection and routing of electrical wiring. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Flexible conduit is available for special purposes....
s. Where they are small and primarily intended to conceal electrical junctions from sight, or protect them from tampering, they are also known as junction box
Junction box
An electrical junction box is a container for electrical connections, usually intended to conceal them from sight and meter tampering. A small metal or plastic junction box may form part of an electrical conduit wiring system in a building, or may be buried in the plaster of a wall, concealed...
es, street cabinets or technically as serving area interface
Serving area interface
The serving area interface or service area interface often called B-box, cross-connect box, cross box, ped , or access point is an outdoor telecommunications cabinet usually mounted on the ground on cable right-of-ways, but sometimes also on telephone poles...
.
See also
- Fiber to the telecom enclosureFiber to the Telecom EnclosureFiber to the telecom enclosure , also sometimes called fiber to the zone , is a standards-compliant structured cabling system architecture that extends the optical fiber backbone network from the equipment room, through the telecom room, and directly to a telecommunications enclosure installed in...
- NEMA enclosure typesNEMA enclosure typesNEMA defines standards for various grades of electrical enclosures typically used in industrial applications. Each is rated to protect against designated environmental conditions. A typical NEMA enclosure might be rated to provide protection against environmental hazards such as water, dust, oil...
- Rack unitRack unitA rack unit or U is a unit of measure used to describe the height of equipment intended for mounting in a 19-inch rack or a 23-inch rack...
- Telco canTelco canA telco can is an outdoor enclosure or metal box where telephone local loop wires come together to be spliced into a larger cable that then runs to the Central Office. They are often just brown metal boxes on the street or side walk...
- Utility vaultUtility vaultA utility vault is an underground room providing access to subterranean public utility equipment, such as valves for water or natural gas pipes, or switchgear for electrical or telecommunications equipment....